XXVIIIth international symposium on macromolecular chemistry (Amherst (USA) 11–16 July 1982)

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agent, adding 15-20 ml alcohol per g PB contained in the gel-fraction. Oxidation should be carried out at room temperature in 5 hr using the following reagent ratios: for 1 g PB 40 ml isopropylbenzene hydroperoxide and 5 ml catalyst (0.1 ~o solution of OsO, in benzene) is used.

Translated by E. S~MERE REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

D. KRANZ, L. MORBITZER and K. OTT, Angew. Makromolek. Chemic 58: 213, 1977 I. M. KOLTHOFF, T. S. LEE and M. A. MAIRS, J. Polymer Sci. 2: 199, 1947 H. SCHUSTER, M. HOFFMAN and K. DINGES, Angew. Makromolek. Chemic 9: 35, 1969 O. BARNARD, J. Polymer Sci. 22: 213, 1956 J. MORI, J. MINOURA and M. JMOTO, Die Makromolek. Chem. 25: 1/2, 1, 1958 J. L. LOCATELLI and G. RIESS, Angew. Makromolek. Chcmie 26: 117, 1972 P. HUBIN-ESCHGER, Angew. Makromolek. Chemie 26: 107, 1972 Metody issledovaniya udaroprochnykh plastikov (Edited by V. M. Gol'perin) p. 76, Khimiya, Leningrad, 1975 E. D. E. HAWKINS, Organicheskiye petekisi, ikh polucheniye i reaktsii, p. 536, Khimiya, Moscow-Leningrad, 1964 V. D. YENAL'YEV, N. A. NOSKOVA, O. P. SHMELEVA and A. A. KUZNETSOV, Rukopis' dep. v ONHTEKHIM, Donetsk. Dep. No. 636XP-82 J. MINOURA, J. MORI and M. JMOTO, Die Makromolek. Chem. 24: 205, 1957 V. P. BUDTOV, N. G. PODOSENOVA, V. M. BELYAYEV and L. L. SUL'ZHENKO, Plast. massy, 2, 36, 1975 N. M. ZALEVSKAYA, Avtoref. dis. na soiskaniye uch. st. kand. khim. nauk, p. 23, In-t fizikoorganicheskoi khimii i uglekhimii, Donetsk, 1981 GOST 12497-78

PolymerScienceU.S.S.R.Vol.26. ~1o.2, pp. 473--495,1984 Printed in Poland

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CURRENT EVENTS XXVIHth INTERNATIONAL SYMPOSIUM ON MACROMOLECULAR CHEMISTRY (Amherst (USA) 11-16 July 1982)* F. S. D'YACHKOVSKII a n d E. F. OLEINIK Tn~ XXVIIIth IUPAC International Symposium on maeromolecutar chemistry held in the University of Massachusetts was a major international event in the field of polymer science bringing together over 1500 persons from many scores of countries. The keynote of the symposium-New Horizons in Polymer Science- determined the special aspects of its conduct (no plenary reports, four one-hour and a few half-hour reports at each of the 16 sections daily). * Vysokomol. soyed..4,26: No. 2, 425-442, 1984.

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......

F, S . D'YACHKOVSKIIand E. F. OLEINIK

~. Over 900 reports were presented to the Symposium the proceedings of which in collated form will not. be printed anywhere. The endeavour of the organizers to give an idea of everything that is now being done in polymer science throughout the world well succeeded. Together with traditional sections the symposium saw new ones at work such as composites, polymers in biology and medicine and Coulombic interactions and polymers in electrical engineering and electronics, which reflects the new trends in current polymer science. We would note that about a quarter of all the papers were presented by companies, principally Am erican. Opening the symposium the president of the division of macromolecular chemistry of IUPAC C. H. Bamford (England) noted that the main feature of scientific work in the field of high molecular weight compounds is the creation of new relations between industry and fundamental science. The organizers of the symposium sought to create an atmosphere of maximum interaction of scientists working in fundamental science and researcher-engineers engaged in technical developments in the field of polymers and polymer materials. A 10 strong delegation of Soviet scientists headed by N. M. Emanuel' took part in the work of the symposium. The papers by Soviet scientists were well received and aroused much interest among foreign colleagues. Particularly widely aclaimed were the contributions of N. M. Emanuel' and N. S. Yenikolopov whose papers were undoubtedly the most interesting in the sections Degradation and Stabilization and Structure and Properties. Unfortunately, the US State Department comitted a hostile act by at the last moment cancelling the travel visas for some well known Soviet scientists invited by the Organizing Committee to present hour-long reports. Spectroscopy of polymers (66 papers). The vast majority of spectral polymer studies are now being conducted by two methods: Fourier IR spectroscopy and high resolution N M R in solids. The number of studies using combination light scatter (c.l.s.) is on the increase. The following problems are chiefly attracting the attention of spectroscopists: study of the character of the mobility of the various chemical groups of macromolecules (both side groups and those forming part of the main chain) in the crystalline and amorphous regions of solid polymers, the influence of external agents (temperature, pressure, strain) on the time and amplitude characteristics of such mobility; the problems of intermolecular interactions in polymer blends; the structure and molecular mobility in polymer glasses; the structure of the highly oriented state of polymers and the special aspects of the structure and behaviour of macromolecules at the interface in composites. It is significant that together with complication of the techniques of spectral studies employed many spectroscopists are paying close attention to study of complex polymer systems such as phenolformaldehyde and epoxide resins, polycarbonates and various polyesters. Among the most interesting results at this section we would note the following. S. Kaplan et al. from. Xerox Corporation (USA) have studied the cis-trans-isomerization of polyacetylene in the solid phase using high resolution N M R methods on solids (with use of the ~3C isotope and the magic angle technique) and Fourier IR spectroscopy. The possibility of quantitative conformational analysis was demonstrated, which is important for elucidating the mechanism of doping and electrical conductivity of polyacetylene. The spectral results confirm the soliton model of conductivity of doped polyacetylene. A detailed critical analysis of the possibilities of the various methods of investigating the special aspects of the lamellar structure of PE hasbeen made in the University of Mainz (GFR) by E. Fischer et al. The paper looks at the methods of c.l.s., differential scanning calorimetry (d.s.c.), electron microscopy and low angle X-ray scatter. The authors concluded that the values of the large periods d derived from the X-ray findings provide information only on the lamellae packed into regular stacks: c.l.s, spectroscopy (change in the frequencies of the longitudinal acoustic modes of vibrations) gives only the mean weighted value of d and is most sensitive to thick lamellae not containing folda; electron microscopy "sees" only the lamellae oriented parallel to the electron beam. Change in T~ri,

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by 2 ° leads to doubling of the thickness of the crystal and d (d.s.c. and c.l.s.). The joint use of different methods enabled the authors to describe correctly a host of observed morphological structures in PE. Some new results have been given by study of molecular mobility in polymer glasses by high iesolution N M R in the solid phase (h.r.s.p.). Thus, in polycarbonate and P E T P J. Schaefer et al. ( M o n s a n t o Company) and also A. Jones et al. (Clark University, USA) found considerable oscillations of the aromatic nuclei well below Tg. The amplitudes of such oscillations are close to 180 ° a n d it is assumed that this type of movement is associated with low temperature relaxation in the systems studied. Analysis of the temperature behaviour of such movements led the authors to postulate that they determine the process of vitrification, though in the last case the movements are more coHelated. Similar movements in epoxide polymer networks were observed by A. Garroway IUS Naval Research Laboratory) who showed that oscillations of the rings appear at 150 K and the rings in the polyepoxide sreorient through 180 ° about the axis i - 4 K higher than this temperature. V. Gronski and M. M o l l e r (Institute fur Makromolekularische Chimie, Freiburg, G F R ) have demonstrated the possibilities of NMR-h.r.s.p. for detecting high energy conformations in glassy polymers while t h e possibility of detecting ionic associates in ionomers by the methods of Fourier t R and N M R spectroscopy was discovered by US researchers. Researchers from the University of Nijmegen (Holland) have studied the slow skeletal movements in P M M A on passing through Tg (NMR-h.r.s.p.) and showed that in the Tg interval no a b r u p t changes in the relaxat ion times occur. Much work has b e e n devoted to study of polymers on their deformation. Spectral methods allow one to see the fine details of the processes at work, follow the orientation of the macromole.ctdes and various segments over the course of the deformation curve and determine Young's modulus a n d the deformation energy. A detailed spectral (Fourier IR) investigation into the melting of polyacetylene and some n-alkanes has been made by J. Zerbi (Milan Polytechnic Institute, Italy). He did not find conformational transitions in the polymethylene chains up to Tmelt. It is shown that the process of migration of the molecules of the n-alkanes as rigid formations apparently occurs in a solid body from one crystal to another. These results call for new thinking on the mechanisms of mass transfer in amorpho-crysIalline polymers and chain structures in general. Analysis of the work presented at the section invites the following conclusions. T h r o u g h o u t the world, in the first place in the USA, spectroscopists are paying much attention to the formation of oriented a n d ultra-highly oriented structures in polymers. In the next few years the NMR-h.r.s. technique may be expected to make an important contribution to the interpretation of the details of the mechanical behaviour of polymers, primarily glassy ones. Advances are also to be expected in the interpretation of the dynamics a n d viscoelasticity of solid polymer systems. The structure of the a m o r p h o u s phase of crystallizing polymers, in the first place PE a n d PP, a n d the mechanisms of their crystallization continue to attract attention. A m o n g the other lines of spectral research a striking feature is the rapid development of Brillouin a n d dynamic (spectroscopy of the correlation of photons) light scatter for polymers. The molecular mechanisms of deformation of polymers are attracting attention. Polymer synthesis and chemistry (177 papers). At the section 11 hour-long papers were read dealing with the new achievements in radical polymerization, stereoregulation, synthesis of high molecular weight polyacetylene derivatives, new linear and network polymers and other problems of m o d e r n polymer chemistry. We would note the growing interest in the synthesis and study o f complex polymer structures, the polymerization of functional monomers and the wide use of physical methods for initiating polymerization processes. Much attention is being paid to the solution of the problem of the incombustibility of polymers a n d the synthesis of fire-proof polymers through polymerization of functionalized monomers. We would also note the increased contribution of research into disperse systems, polymerization

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on solid surfaces and the synthesis of polymer-polymer composites in the course of polymerization. On the production of polymer materials of great interest is the development of the process of obtaining low density linear polyethylene at low pressures (LP-LDLPE). The process of the synthesis of LP-LDLPE consists in the copolymerization of ethylene with C4-Cs ~ olefines, for example, with ~-butylene. In the reaction in the gaseous phase one may directly obtain a granulated polymer in the course of synthesis, which greatly improves the economy of the process. In strength indices LPLDLPE well exceeds the usual LPPE. This gives a substantial gain in the sphere of exploitation and manufacture of products (in particular, films) from this material. The paper by T. Tsuruta (University of Tokyo, Japan) discussed the results of synthesis of functional polymers with units containing amino groups. The investigations were carried out in three directions. 1. Synthesis of macromers with polyamine chains. As starting reactants they used for example N,N-diethylethylene diamine and 1,2-divinyl benzene. A polyamine macromer was obtained or~ lithium alkyl amides by the poly-attachment reaction. Polymers have been obtained with M = 10004000. The synthesized new polymer products are soluble in organic solvents and water. 2. Obtaining soluble poly-l,4-divinyl benzenes and their amino derivatives. It was found that 1,4-divinyl benzene (DVB) is capable of polymerizing under the influence of lithium catalysts in THF. When the reaction proceeds in presence of excess diisopropylamine, the soluble polymer poly-l,4-DVB forms the units of which contain non-reactifig vinyl groups which are readily transferred to alkylaminoethyl gro ups. Thus it is possible to obtain water-soluble functional polymers with side diethyltriamine groups. 3. Obtaining isoprene amino group-containing oligomers with M = ~ 1000 by oligomerization. of isoprene in presence of lithium alkylamides. Then similarly to the preceding case, alkylation o f the double bonds of the oligomer is carried out. The interest of the listeners was aroused by the paper of T. Otsu "Radical Polymerization of 1,2-Substituted Ethylene Monomers" (University of Osaka, Japan). The author showed that contrary to the generally accepted view that radical polymerization of 1,2-substituted ethylene is impossible such monomers as dialkylfumarates polymerize comparatively readily under the influence of radical initiators with formation of polymers with high molecular weight. D. Hardy (Plastics Institute, HPR) reported on a study of polymerization and copolymerization reactions of liquid crystalline monomers containing mesogcnic groups in the side chains. The paper by J. Salamone (Lowell University, USA) dealt with the problems of synthesis and study of the properties of new amphoteric ionomers. The paper by A. Chapiro (France) presented data on the matrix effect in the polymerization o f acrylic acid and acrylonitrile. The observed self-acceleration in the author's view is due to the formation of oriented polycomplexes between the monomer and the polymer units creating the conditions for high rates of chain prolongation. J. Kennedy (USA) went into the synthesis of new linear and network polymers on cationic polymerization of functional monomers. Synthesis involves the formation of reactive prepolymers and oligomcrs with terminal functional groups. The paper by J. Eastmond (Liverpool University, England) proposed a new way of synthesizing block cop01ymers (for example PS and PMMA) consisting in "switching" the ionic mechanism of growth to radical achieved by disruption of the ionic centres of polymerization with an excess of bromiac. The brominated terminal groups formed are later used to initiate radical polymerization. The work of Soviet chemists at the section was represented by the papers of I. M. Papisov and D. A. Topchiyev. It should be noted that many scientists are continuing to work'in the field of polymer synthesis and this section was the largest (to go by the number of papers) at the symposium. Catalysts and catalysis (41 papers). The largest number of papers in this section (25) was concerned with the catalytic polymerization of ethylene. Attention was concentrated on the results of study of new highly active catalytic systems and study of the structure of the polymer as a function

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o f the catalyst used. The most effective catalytic systems contain titanium and magnesium chlorides

(TM-catalysts). In the case of polymerization of propylene these systems include alkylaromatic ethers which act as stereo-regulating additives. Various modifications of TM-eatalysts were reported distinguished by the methods of preparation, the additives and the ratio of components. A number of papers on this subject were presented by major companies (Montedison, Hoechst and Dart) which have used TM-catalysts to devise new large tonnage processes for obtaining PE and PP by a simplified technological scheme. The main tasks in this field were formulated as follows: further refinement of catalysts to raise their stability, improvement of stereoregulation, control of the granulometric composition of the polymer and its M W D physicochemical investigations into the processes of formation of the composition of catalysts, kinetic studies of homo- and copolymerization of olefines, devising methods for determining the number of active centres and quantitative evaluation of the parameters of the elementary stages of the process. Other papers looked at the work on polymerization of ethylene and its copolymerization with propylene on chromium oxide catalysts, study of homogeneous catalytic systems, polymer catalysts and study of the mechanism of catalytic polymerization by calculation methods. Two papers were concerned with study of the process of formation and composition of TMsystems (V. A. Zakharov, Institute of Catalysis, Sib. Div., U.S.S.R. Academy Sciences) and study of the mechanism of catalytic polymerization of the olefines by calculation methods (2.2. Zakharov, Institute of Catalysis, Sib. Div., U.S.S.R. Academy Sciences). The paper by T. Kwei (Tokyo Institute of Technology, Japan) reviewed the results on widening the M W D of the polyolefines formed on solid catalysts. It was concluded that the inhomogeneity of the surface of the catalyst plays a decisive role in the widening of the M W D and homogeneous and solid catalysts were compared from this angle. J. Chien (Massachusetts University, Amherst, USA) presented experimental data on the complex physieochemical conversions occurring at each of the five stages of the preparation of the multicomponent TM-catalyst, which is of interest in selecting the optimal conditions for the synthesis of such catalysts. The paper by I. Doi (Tokyo Institute of Technology, Japan) on gas phase polymerization o f propylene on highly active applied TM-catalysts presented information on the microstrueture of the PP formed. It is concluded that atactic PP constitutes a stereo-block copolymer consisting of iso- and syndio sequences. It is assumed that on the catalyst surface there exist active centres at which during polymerization reversible transition of the iso-syndio structures takes place. The paper by A. Langer, Chemistry of Applied Catalysts for the Polymerization of Propylene (Linder Scientific Laboratory, USA), examined the chemical reactions occurring between the components of TM-catalysts and established that during the interactions alkylation and reduction o f ethyl benzoate occur. The products formed play a role in the regulation of the activity and stereospecificity. V. Kaminsky (Hamburg University, G F R ) presented an interesting paper Homogeneous Highly Active Catalysts with an Alumoxane Component. Catalysts based on zirconium compounds combined with methylahimoxane possess high stable activity allowing up to 800 kg PE to be obtained per hr per g of zirconium at a pressure of 1 atm. They may be readily fixed on the surface o f inorganic and organic carriers. Using g-olefines as comonomers it is easy to regulate the density and molecular weight of the polymer, i.e. to 'obtain low density PE including on the surface of inorganic carriers. The paper by P. Galli (G. Natta Research Centre, Italy) considered the general theoretical aspects and practical problems of using complex catalysts on polymerization of olefines, emphasizing the important influence of amorphization of magnesium chloride on the activity of TM-catabsts. Catalysts have been formulated with a regulatable form of particles which allow granulated PP to be obtained directly in the course of its synthesis. It is considered that the development of such a catalyst for the polymerization of propylene in the suspension regime is a major tcchnical achievement. A so-called ideal technological scheme for obtaining PE and PP in a light solvent and by granulation of the polymer in the course of synthesis was also presented.

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F. S. D'YACHOVSKUand E. F. OLEINIK

The paper by J. Hogan (Phillips, USA) dealt with gas phase polymerization and copolymeriza.tion of the olefines in presence of a chromium oxide catalyst in the gas phase. Copolymerization of ,ethylene with a-olefines in presence of this catalyst gives low density PE (0.92--0.93 g/cma). The author considers that gas phase "linear PE" obtained on chromium oxide catalysts differs little from commercial low density PE obtained at low pressure. The final session was addressed by F. F. D'yachkovskii (Inst. Chem. Phys., U.S.S.R. Academy of Sciences) who reported on a new line of synthesis of catalytic systems of polymerization of the olefines on polymer carriers. The paper was heard with much interest, elicited many questions and a lively discussion. As a whole the work of the section was highly productive. The highly effective catalytic systems developed in tbe last few years have greatly simplified the technological production schemes for polyolefines. Of the greatest practical importance are TM-catalysts and catalysts on carriers. An •exceptionally important problem is working out ways of controlling the granulometric composition of the polymer formed and its MWD. Degradation and stabilization of polymers (32 papers). A joint paper by scientists of the Californian Institute of Technology and the Urtiversities of California and Massachusetts looked at the mechanism of deactivation of electron-excited states in copolymer benzotriazole and methylmethacrylate derivatives. The process of energy transfer represents the formation of crosslinks. In addition, another main photo-oxidation product f o r m s - hydroxyl groups, chiefly on the surface of the polymer film. The primary mechanism of thermal decomposition of the polyurethanes formed the theme of the paper by S. Foti et aL (Institute of Industri~il Chemistry, Catania, Italy). Correlations between the chemical structure, the mechanism of thermal decomposition and thermal stability were established. The paper by the Italian scientists M. Gleria et aL (Institute of Radiation and Photochemistry, Padua) looked at the photochemical behaviour of the polyorganophosphazenes. It was shown that in all experimental conditions the reaction of formation of crosslinks prevails. In an hour report with lively discussion N. M. Emanuel' (U.S.S.R.) spoke of the new results o f chemicophysical research into the ageing and stabilization of polymer materials obtained in the Institute of Chemical Physics, U.S.S.R. Academy of Sciences and in the Moscow State University. Much interest was aroused by the possibility of mathematically describing the whole variety of kinetic curves observed in the experiment on ageing of polymers in different conditions. A leading specialist in the field of polymer degradation and combustion N. Grassie (Glasgow University, Great Britain) in his paper dealt with the degradation of phosphorus-containing polyurethanes. Combustion is described as a three-stage process; in the first phase a liquid product forms, then its combustion is observed and in the third phase heat is transferred back to the polymer, which also continues the cycle. The search for additives lowering the combustibility of polymers must apparently start from this mechani sin. Extensive information on photopolymerization under a laser beam was presented by P. Castle (Westinghouse, USA). A number of common patterns were established for the acrylates and methacrylates studied by him: the reaction is arrested immediately on blocking the laser beam, the process of polymerization occurs not on the surface but in the whole mass of the solution, etc. In the work he used p-benzoquinone which is photochemically excited on exposure to the radiation of an Ar-laser. Important investigations into the combustion and thermal decomposition of polymers are under way in London University. This work was reported by C. Cullis and M. Hirschler who devoted their paper to the problems of thermal stability and capacity for ignition of organic polymers. The authors like Grassie emphasized that the combustion of organic polymers is a complex process with a large number of interrelated stages. The applicability of thermal analysis as a method for studying the effectiveness of the additives used to prevent combustion of polymer materials was considered. G. Scott (Birmingham University, England) reported on the role of stable radicals as anti-oxi-

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dants for polymers with analysis of the possible schemes of their action. As is known, this approach was first developed in the U.S.S.R. and the first stable radicals for these purposes were synthesized in our country. Oxidation of polymers and model systems was considered in his paper by L. Dulog (Institut fiir Technologische Chemic, Universit/it Stuttgart, GFR). The numerical data on the activation enthalpies and entropies of oxidation of bis-hydroperoxides in benzene may be of interest. A large number of special papers were also presented on thermal decomposition and combustion of polymers and additives preventing combustion, photodegradation of PVC on exposure to sunlight, thermal oxidation of the polyolefines, photostabilization of the polyolcfines and use of chemiluminescence to study the degradation of polymers (unfortunately without references to Soviet work in which this method was first developed). Of interest was the paper by L. Waiters and V. Landi (Rodgers, USA) presenting kinetic data o a the high temperature process of degradation of phenolformaldehyde plastics. The well known scientist in the field of polymer ageing and stabilization B. Ranby (Technological Institute, Stockholm, Sweden) presented a methodological report on primary photo-oxidative reactions in polymers. In the work of the section there was an obvious lack of generalizations and the attempt at such made in a Soviet paper (N. M. Emanuel') met with much approval. Polymers in biology and medicine (68 papers). The paper by D. Lyman (University of Utah, Salt Lake City, USA) considered the problems of the biocompatibility of polymers used for constructing artificial blood vessels. The principle of producing biocompatible polymers for such vessels was proposed consisting in sealing from thin fibres tubes which on contact with blood are covered with endothelium automatically compatible with the blood. The paper by P. Justy (University of Pisa, italy) presented material on the synthesis and characterization of new haemoeompatible thermoelastoplasts from which the corresponding polyurethanes are synthesized by cationic and anionic polymerization. The synthesis of block copolymers of styrene, ~-methylstyrene and isobutylene using "quasi-live" cationic polymerization under the influence of organoaluminium compounds and cationogenie additives (CI2, HCI, PC13, etc.) was described. On interaction with various diisocyanates a,o)-polyisobutylenediols form new polyurethanes used to obtain prostheses for blood vessels and the tunics for them. The paper by T. Kalal (CSSR) discussed water-soluble polymers with triiodobenzoic acid derivatives in the side chains; these polymers are used as macromolecular contrast agents in lymphography. The polymer was based on dextrin and synthetic N-substituted aspartamides. The author has formulated new diagnostic polymers based on polyglycidy[methaerylate and its copolymers in the form of monodisperse microspheres. The paper by L. Cohen (USA) examined the possibility of using synthetic D N A for generating secondary specific mutations. C. Overberger (University of Michigan, USA) dealt with the synthesis of polynueleotide models presenting the results of study of systems of hydrophilie polymers possessing both chirality and structural order similar to nucleic acids. Models of biological polymers were synthesized and their interaction with each other and with polynucleotides studied.

1

C'--"O

where B = A , T, C, A~A.

NH

NH

H

H

480

F . S . D'YACHKOVSKIIand E. F. OLer~K

The section paid a great deal of attention to the problems of thrombus formation on contact of polymers with live tissues and the synthesis of thrombolytic polymers. We would note the growing interest in the use of composite materials in biological systems and also for medical purposes. The development of biologically active oligomer and polymer preparations including spin-labelled polymer preparations for topologically directed chemotherapy are interesting. A discussion was held on the problems of synthetid~models of biological membranes, the use of microencapsulated polymers with functional groups for synthesizing medicinal preparations and transfer of oxygen by porphyrin complexes and the problems of synthesizing anti-turnout polymer preparations and conformational analysis of complex biologically active polymers. Use of polymers in electrical enuineering and electronics (48 papers). The appearance of such a section at a macromolecular symposium and the large number of papers read to it point to the success in obtaining polymers and materials based on them with interesting electrical properties and also the importance and prospects for such materials in modern technology. The work presented to this section covered a number of problems of electric conducting polymers: the synthesis of new conducting systems; conducting polymer blends and copolymers; the structure and mechanism of conductivity, doping and the mechanism of conductivity of doped systems; and the influence of the external conditions on conductivity. The objects of research in this division are polyacetylene, polydiacetylene, conducting polymers based on the pyrroles, doped poly-p-phenylenevinyleneand fluorometallophthalocyanins. Other lines are piezo-, pyrro- and ferroelectrical properties of polymers (here the most important research object is PVDP and its copolymers with trifluoroethylene) and photo- and electron-sensitive polymers and, finally, attempts at obtaining new materials for the semiconductor industry. K. Wayne et al. from the US Naval Research Laboratory (Washington, USA) have devised a new effective highly conducting system based on phthalocyanin metalfluorides (AI, Ga). Using for doping the nitrozonium BF2 and PF~ salts they managed to obtain composites with a conductivity 3 x 10 -2 and 2 x 10-1 ~ - t cm- l, respectively. The samples are distinguished by good stability to thermal factors and the action of the environment (no conductivity change on keeping in air for a year). The authors note that these materials may be readily obtained in the form of sublimated films and their conductivity may be changed by doping by 7-9 orders. Of the new polyene systems interesting results have been obtained by scientists at the Xerox Corporation (USA) on polymers synthesized from propiolic anhydride the cyclopolymerization of which [catalyzed by weak anions (I-, CNS-, etc.) or coordination catalysts of the PdCI2 type]' gives a polymer of the following structure: 0

~/ 0 \j 111

0

t

III

r°,/o\ffo 7 \

{jjl.

\

\t

Subsequent hydrolysis of polypropiolie anhydride leads to the polyene

\ J \ (J\)v n Doping of these systems leads to conductivities 5 x 10-*-10 -7 ~.)-x cm-1 (20oc, pressed pellets). From the material science point of view of interest are the PE-polyacetylene composites developed by G. Wnek (Massachusetts Institute of Technology, USA). Such composites are obtained in situ: a film of commercial LDPE is impregnated with Ti (OBu), : EtaAl followed by admission of gaseous acetylene to the system (ll0°C, 24 lax). The composite film is doped by immersing it it~ solution of I2 : pentane. The conductivity of such a composite reaches 10 £/-1 c m - t

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The search for new catalysts for polymerizing acetylene and new doping agents for P A is continuing. The catal~,sts WCI4-Ph4Sn and MoCIs-Ph4Sn give a polymer with 90% content of trans~units and AIEt3-Ti (OBu)4 a polymer with 60 % content of cis-urfits. The new doping agents (CF3SO3, WCIr, MoCI~) have so far given conductivities not better than 10-20 ~ - 1 era- 1 (20°C). In attempts to look for new derivatives and semiconducting polymers new syntheses have ~been made on the basis of heteroaromatic compounds such as pyrroles, furane, pyridine and di"benzothiophene and also vinylenes with heteroaromatic nuclei such as stilbene, poly-(1,4-phenylenevinylene, etc.) (Freie Universitht, Berlin) the furanes proved best of this polymer series. Doping v¢ith AsF5 gave polymer samples with a conductivity 0"2 f~-~ cm-~ (20°C) and activation energy .of conductivity 0.40 eV. The negative activation energy of conductivity, i.e. metal-like behaviour, is unusual. Also of interest is the attempt to sy~nthesize polyconjugated systems through polymerization ,via the reactions of metathesis

ilHicoo 0

HO ~---~OH -~ ~ n

The end product gives a conductivity without doping of 10 -a I'~-1 c m - I (20oc). (A. Alimuniar e t al., Durham University, England). Modern techniques call for the production of polymers sensitive to an electron beam. Investigations show that the various polyvinyl pyridinium salts are potentially promising for these purposes (K. Lee, GTE, USA). Another important technical task is the creation of materials for X-ray lithography. In this ,case it is necessary to have polymers selectively absorbing radiations in the region 5-20 A (roentgeno resists) with high sensitivity (over 50 m J ' c m - 2 ) . Some success has been achieved on halogenated acrylate and methacrylate polymers (L. Thompson, Bell Telephone, USA). Interesting work has been done by the Japanese scientists (S. Miyata et al., Tokyo) in producing photodiodes of the metal-polymer-metal and metal-polymer-semiconductor type on the basis of the technique of precipitating in vacuo a thin film of a crystalline polymer on a glass support. Control of the structure of the polymer crystals and the conditions of formation of the film led to an appreciable increase in the efficiency of the conversion of solar to electrical energy. A number of papers dealt with the theoretical problems of the conductivity of polymers. The efficienc2, of the photochemical conversion of the energy of visible light is an important characteristic of solar batteries. Japanese authors (M. Kaneko et aL) showed that the complexes of tris-(2,2'bipyridyl)ruthenium (II) with polymers are promising candidates for such materials since they well catalyze the photolysis of water. Composites (42 papers). Two main lines of work were represented at this section. 1. Composites reinforced with short fibres (glass, carbon). As matrices thermoplasts (in the first place PP) and thermoreactive polymers-el~oxides, polyesters-are used in such composites. The main task of these investigations is to produce materials with good mechanical properties and long-

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term stability which can be rapidly and effectively processed on standard extruders and moulding machines. The tendency to produce such systems has become dominant in polymer material handling since only by stepping up the manufacture of products from composites will it be possible to solve the economic problems still preventing the wide replacement of metals in traditional branches o f technology, for example, the motor car industry. It is now clear that polymer composites with a smaller specific weight possess almost all the requisite properties allowing them to widely replace metals. 2. Another important line is study of materials with high resilience. In this connexion a number of papers at the section were devoted to analysis of the mechanism of absorption of mechanical energy by heterogeneous rubbery phase inclusions dispersed in a glassy matrix. A very deep level of understanding of the subtle mechanisms of growth and retardation of the spread of cracks in heterogeneous systems has now been reached and the development of the theory already allows one in substance to "construct" materials with preset mechanical properties and crack resistance. Work here is being done at a very high experimental and theoretical level. Thus, S. Bucknell (Cranfield Institute of Technology, England) on the basis of a wide range of experimental data has analysed the possible coexistence in a composite of four types of deformation behaviour: formation of shear bands, non-localized shear, crazing and formation of voids of the cavitation type within or aroud the filler particles. To predict the behaviour of the material it is very important to establish what mechanism dominates and in what condition (temperature, particle size and content). The action of a filler of any type essentially boils down to lowering the fluidity limit of the matrix about the filler particles. However, fillers of different type (rubbery particles and rigid glass beads). behave differently. Rubbery particles promote the formation of crazes and shear bands but rigid beads do not always do so. The ability of rubbery particles to withstand heavy deformation and redistribute the stresses in the surrounding glassy matrix is a most important characteristic for producing shock-proof materials. An important factor in increasing impact strength is the acceleration of the process and localization of the deformation in the shear bands. An extremely interesting study was presented by M. Takayanagi (Kyusu University, Japan) who has attempted to produce "molecular composites" using the ability of the structure of some rigid chain polymers to retain their rigidity and high mechanical properties not only in the form of fibres but also in the form of microfibrils and also at the level of the large fragments of isolated molecules. He proposed that polymers be strengthened not with fibres of macroscopic size but macromolecules of rigid chain polymers. Using for strengthening poly-p-phenylene terephthalamide (PPTPA) and polybenzamide (PBA) in different matrices he obtained material with a very high mechanical properties. Thus, the PPTPA composite (5 7o) in a nylon matrix has a strength of 60 MPa, i.e. three times that of the initial matrix. Aramide microfibrils form a physical mesh in a nylon matrix, which also leads to high mechanical properties of the system. The synthesis of tri- and multiblock copolymers of aramide macromolecules with nylon gave a strong material with high elongation at rupture (ea=100-200~). The introduction of rigid aramide molecules into the PVC matrix also helped to reach high deformability of the molecular composite. Toughening butadiene nitrile rubber with 6"4 70 PPTPA in fibrillar or microfibrillar form gave a composite with Young's modulus 13 MPa and strength 26 MPa, which is higher than the corresponding values for carbon black filled vulcanizates (40 carbon black). The PPTPA composite with the matrix-polymer of the ethylene type has a fluidity limit of 35 MPa as compared with 10 MPa for the initial matrix. This pioneering work of Takayanagi undoubtedly opens up new possibilities for obtaining composites with a polymer matrix. Attempts to produce molecular composites have also been made by other researchers (V. Wang et aL, Dayton University and the US Air Force Research Laboratory). A rigid reinforcing polymer-poly-p-phenylenebenzbisthiazole was dispersed from solution in the matrix of flexible chain poly-2,5(6)-benzimidazole. The composite obtained (film) has Young's modulus E = 9 GPa, strength 190 MPa for an elongation at rupture of 4 ~o. Active development of this new way of obtaining constructional polymer materials has begun only in the last few years.

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A m o n g the other ways of producing composites we would note the attempt to obtain composites in situ (G. Kiss, Celanese, USA). The idea is based o n the fact that anisotropie reinforcing elements form during the manufacture of the products. The formation of monocrystalline whiskers of polyoxymethylene from trioxane (TO) is a n example of such a process. After f o r m a t i o n and cooling of the polymer matrix with additives of TO the latter forms anisotropic needle crystals which are then readily polymerized by g a m m a radiation. Monocrystalline wkiskers of polyoxymethylene (POM) have also been used to reinforce epoxide and polyolefine matrices, which raised Young's modulus to 7 G P a (16% POM). Diaphragms h a v e made from this material for sound dynamics which appreciably improve the quality of musical sounds at frequencies > 10 kHz. To raise the homogeneity of the epoxide matrices for composites a n attempt has been m a d e to synthesize mutually penetrating networks of epoxide-unsaturated polyester-styrene (P. Heintz and A. Gourdenne, France). It is interesting to note that these systems were heated by the microwave m e t h o d to carry out the chemical reactions of network formation. It appears that this method of heating for processing polymer composites will be actively developed in the near future. Molecular dynamics (36 papers). This section considered a wide spectrum of problems o n the influence of molecular mobility in polymers o n their properties a n d reactivity. Thus, one of the central problems is that of the special features of molecular mobility in solid amorpho-crystalline polymers. R. Boyd a n d P. Alvin (University of Utah, Salt Lake City, USA) have investigated the mechanical and dielectric relaxation of a n u m b e r of linear polyesters as a function of the crystalline phase in them. It turned out that the crystalline phase has a fundamental influence on molecular mobility in the amorphous phase, in particular, appreciably widening the relaxation time spectrum in the beta-transition but not influencing the gamma relaxation. R. Porter et aL (University of Massachusetts, USA) have studied the role of the initial morphology of PEPT on the process of deformation and the properties of extruded samples. It turned out that samples obtained from the initial a m o r p h o u s PETP appreciably differ from those obtained from the partially crystalline polymer. Molecular mobility in the former is greatly facilitated. The authors postulate the presence in the extrudate of regions of oriented a n d isotropically arranged segments. Much interest was aroused by the work of A. Jamieson a n d R. Simha (Cleveland Institute o f Technology, USA) o n dynamic light scatter in polymer glasses. They obtained a very i m p o r t a n t new result in polymers vitrified under raised pressures ( > 1 kbar) not a fall in the value of the density fluctuations (Ap 2) is observed, as expected from the quasi-equilibrium theories of the glassy state, but a n increase. The reasons for this unexpected behaviour of glasses are still not clear. Results of fundamental importance on the kinetics of the conformational transitions in macromolecules were presented by E. Helfand (Bell Telephone Ltd., USA). He showed that the mobility of the conformation type in the chains is a local process a n d the most typical "elementary" rearrangement is that similar to a "crankshaft". However unlike the movement of this type earlier proposed by P. Shatsky a n d R. Boyer the real rearrangement always occurs by the "one-barrier mechanism". The cooperativeness of the transition consists in the fact that after the j u m p of one of the chemical bonds of the chain through the barrier into the new conformation the probability of the j u m p of the other bonds in the transition of the first type considerably rises. P. Flory (Standford University, USA) examined in detail the current state of the theory of high elasticity. From analysis of the experiment and the existing theories the a u t h o r concluded that at present there are no grounds for considering that the mechanical load in rubber-like systems is carried by topological (trapped) meshings as well as by chemical crosslinks. A n u m b e r of papers considered the special aspects of mobility in polymer gels and the influence of the size of the macromolecules on their reactivity in dilute solutions. Thus, O. Olaj and G. Ziferer (Universit/it Wien, Austria) using the Monte Carlo method showed that the rate constant of the bimolecular reaction between two polymer coils appreciably changes with the length of the chain by a power law a n d the exponent depends o n the position of the active centres in the c h a i n - a t the ends or in the middle.

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The attention of the participants in the conference was attracted by the paper by G. Patterson .(Bell Telephone Ltd., USA) o n dynamic a n d Brillouin light scatter in block polymers. The relaxation functions obtained from the experiments o n scatter in the interval 10 -6 to 102 give new information .on the structure of the polymer close to Ts. The results given by this method already provide additional information as c o m p a r e d with the classical relaxation methods such as dielectric. The applic a t i o n of this method to solutions of polyelectrolytes (N. N e m o t o and M. Kurata, University of Kyoto, Japan) revealed the appearance of far order in the disposition of latex particles, which is d u e to the forces of electrostatic repulsion of the latex particles. J. O'Reilly ( E a s t m a n Kodak, USA) considered the special aspects of the dynamics of P M M A a s a function of the degree of its stereoregularity. He showed that the vibrations of the macromole~cule make a notable contribution to change in the thermal capacity of P M M A at T~ a n d that the position of T~ is one of the most sensitive properties with change in microstructure. The work of the section showed that the problems of the subtle mechanism of molecular mo,bility continue to be a focus of attention for scientists although now the greatest attention is con~entrated o n the search for the link between various forms of movements a n d the physical and, in particular, mechanical properties of block polymers in the melt a n d solid state. Elastomers (36 papers). All the papers at this section may be nominally divided into two major groups: synthesis and study of the properties of elastomers with heterophasic structure (majority) a n d work o n the theory of the highly elastic state. They were concerned with block copolymer systems, phase separation in which is due to the s t r u c t u r e of the blocks of different chemical nature a n d also filled (composite) systems. A m o n g the block-copolymer systems considered in this section we would note the segmented polyurethanes with rigid blocks, graft polybutadiene or nitrile rubber copolymers with polyletrahydrofurane, J. Blackwell et aL (Cleveland Institute of Technology, USA) studied the structure o f the h a r d phase in which the polyurethane segments are associated a n d showed their preferential t e n d e n c y to orientation. M. Droscher a n d U. Bandara (Institut fiir Makromolekularische Chemie, Freiburg, G F R ) l o o k e d at the structure a n d properties of certain copolyesters (simple and complex). They found that these thermoelastoplasts are well extruded in the solid state a n d the properties of the extrud a t e essentially depend on the morphology of the initial polymer. Interest was aroused by the paper by G. Finkelmann (Clansthal Hochschule, G F R ) o n the synthesis and properties of elastomers o f a new type containing liquid crystalline blocks. The main chains of the network are built of polysiloxane fragments a n d the liquid crystalline blocks with small mesogenic groups are introduced together with the hardening agent. It was found that the mesogenic groups form oriented associates in the netwok (above Tg) and the planes of the hard mesogenic groups are oriented perpendicular to the polysiloxane chains. This structure freezes with fall in temperature. Characteristic •of new liquid crystalline elastomers are certain special properties, in particular, the unusual dependence of mechanical stress o n temperature. In the communication by R. Sembrol (General Tire, USA) we find a clear link between the electrical resistance of vulcanizates a n d the dispersity of the filler: the higher the dispersity the lower the resistance. It is significant that the other physical properties cease to "sense" the dispersity of the filler m u c h earlier t h a n the electrical resistance. Of the other studies at this section we would note that of S. Prevorsek and V. D e b o n (Allied Corporation, USA) o n the aromatic polycarbonates, polyester carbonates and complex polyesters. The m a i n object of this study was to show that the molecular meshings play a prominent role in the mechanical behaviour of polymers not only in the rubber-like state but also below Tg. Rise in the rigidity of the chains of the network considerably increases the mutual penetration of the chains, i.e. makes phase separation more difficult. B. Maxwell a n d G. Jasso (Princeton University, USA) showed that a blend of incompatible polymers may be so prepared that it will have the morphology of continuous three-dimensional interpenetrating phases. I n this case the blend has the high elasticity of the melt so that it may be

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transformed into a structure with a high degree of orientation. It is significant that heating does not destroy the above mentioned morphology. G. Kraus and V. White (Phillips Petroleum Co., USA) were the first to present systematic data on the rheology of the melt of polyphenylene s u l p h i d e - a n important constructional plastic recently formulated by the company. The well known specialist on adhesion A. Gent (Akron University, USA) presented a review of the degradation of adhesives and concluded that allowance only for the chemical and van der WaaFs interactions within the glue cannot satisfactorily describe this complex process. Better results are now given by analysing the glues within the model of the compositional material. Structure and properties of polymers (85 papers). Despite the large number of sections, the problems of the structure of polymers and the links between st~ t~cture and properties continued to remain the most interesting for the participants of the symposium. Among the Soviet scientists addressing this section were N. S. Yenikolopov G. L. Slonimskii and E. F. Oleinik. The paper by N. S. Yenikolopov, Some Problems of the Chemistry of Plastic Flow, aroused enormous interest among the audience a lively discussion and comments. In the view of leading foreign scientists the results presented by N. S. Yenikopolov were among the most telling and stimulating in present day polymer science and the paper was recognized as one of the most intelesting at the symposium. The papels to this section may schematically be divided into five major groups. 1. The structure and morphology of the crystalline phase in crystallizing polymers and its influence on the properties (primarily mechanical) of the samples. 2. The structure of polymer crystals, the structure of the defects characteristic of polymer systems. 3. The mechanisms of polymer deformation. 4. The glassy state of polymers. 5. New methods for evaluating the various structural characteristics and physicomechanical properties of polymers. A. Keller (Bristol University, England) using "shish-kebab" PE examined the link between the elasticity modulus, strength and morphology of crystals of this polymer. He clearly showed that on crystallization of PE from a melt Young's modulus is determined by the elements of the "kebab" type which intermesh on uniaxial loading of the sample. Such structural meshings allow modulus values of up to 100 GPa to be reached despite the low (5 ~ ) concentration of these morphological formations. On storage of the samples additional crystallization produces a "self-consolidation" effect. On crystallization from solution rise in the modulus is always observed with in To,. In this case rigidity and strength of the system are due to structures of the "shish" type i.e. fibrous formations constructed from oriented crystalline segments the mean value of which rises with increase in T¢,. Subsequent thermal treatment profoundly changes the structure of the "kebabs" but weakly influences the value of the modulus of the samples crystallized from solution. L. Mandelkern (University of Florida, USA) presented a review dealing with the structure of the defective regions binding the lamellar erystallites and the contribution of defectiveness of the various phases of the polymer to the mechanical properties and molecular mobility. The author of the concept of paracrystallinity R. Hosemann (Freie Universit/it, Berlin) delivered a paper on the "Physics of Microparacrystals" Consistently developing the idea of paracrystallinity he considers that the structure of biopolymers and synthetic polymers, catalysts, pyrolytic graphites and metal melts must now be regarded as microparaerystalline. A special feature of microparacrystalline formations is the self-limitation of their growth by virtue of the fact that the free energy of the growing seed begins to exceed the surface energy because of the paracrystalline distortions in volume. A very interesting paper was presented by T. Ito (Kyoto Institute of Technology, Japan) reviewing the deformability of polymer crystals in conditions of hydrostatic compression. Direct measurements showed that practically for all types of polymer crystals (with flat and helical chains) the deformations in the Hooke region perpendicular to the axes of the chains exceed

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by two orders those along the axis of the chain and this anisotropy is an internal property of macromolecular systems. The defects of the crystal (branches or side groups) always increase the compressibility of the crystal in the perpendicular direction. A notable role in lowering compressibility is played by the hydrogen bonds (nylon-6). Unexpected results on the mechanical behaviour of the polyamide fibres have been obtained by Indian investigators. It turns out that with rise in the humidity of the medium the mechanical properties (strength, Young's modulus, ultrasonic modulus) and also the density and crystallinity of the fibre rise. R. Porter et al. (University of Massachusetts, USA) reported on the morphological and other structural changes in high density PE after extrusion. In addition, R. Porter and L. Wang (Fudan University, Shanghai, China) reported on the properties of samples of ultra-highly oriented PS obtained by coextrusion in the solid state. For atactic PS samples it was possible to reach degrees of stretching of 1-15 and for isotactic 1-7.5. A. Pennings (University of Groningen, Netherlands) reviewed his work to obtain ultra-high strength and high-modulus PE fibres. The fibres were obtained by orientation crystallization from dilute solution on a support. Strength values of 4.7 GPa and modulus 160 were obtained for such fibres. A. Peterlin (National Bureau of Standards, USA) presented a major review of the physical properties of oriented crystalline polymers. Stretching or extrusion of polymers in the solid state leads to orientation, although the morphological changes in the polymer are chiefly responsible for the substantial change in the mechanical properties. The changes in the properties were interpreted by the author within the context of the microfibrillax model. The axial modulus of such systems is determined by the mean volumetric fraction of "through chains" intersecting the amorphous regions, while the strength depends on the defects of the microfibrillar structure. Direct measurements of the permeability of the amorphous regions of the oriented polymer showed the practical invariability of the fibrillar structure of the amorphous regions even for maximal stretching. Chinese scientists (Hu Mao et al., Institute of Chemistr2~, Chinese Acad, Sci., Peking). who have studied PETP films also took "up the problems of investigating the mechanical behaviour of polymers in connexion with the structure of the crystals. They showed that the differences in the rates of crystallization of this polymer significantly affect the mechanical behaviour of the films on stretching. Much attention was paid to study of the structure of various polymer crystals artd analysis of the crystallization process. J. Magill (University of Pittsburg, USA) examined in detail the morphology of the surface of polysiloxane crystals. A number of papers were concerned with the structure of crystals of PTPE which is capable of forming several crystalline modifications and also the structure of PVDP. The defects in PTPE crystals were also considered in detail and it was shown that the energetically most preferable defect is the "coordinated rotation" of the macromolecules in crystalline surroundings. Interesting work on the structure and deformation of polydiacetylene monocrystalline fibres was presented by R. Young and G. Galiotis (Queen Mary's College, England). They found such fibres have moduli of 45-61 GPa and the strength of the defect-free fibre is close to 2.5 GPa, which indicates the good packing of the very strong macromolecules irt the fibre. C. Bailly et aL (Universit~ de Louvain, Belgium) found that the organic salts of alkaline metals (for example, Na o-chlorobenzoate) are strong promoters of crystallization of polycarbonate. It is interesting that in presence of these compounds the degree of crystallinity reaches 60 % and Tin©it = 300°C i.e. close to the thermodynamically equilibrium Tin©Itof this polymer. T. Juska and I. Harrison (University of Pennsylvania, USA) proposed the mechanism of plastic deformation of amorphocrystalline polymers based on notions on the melting-crystallizationphase transition induced by mechanical stress. The well known French scientists B. Escaig and D. Lefebvre (Lille Technical University, France) considered the mechanism of plasticity in glassy polymers. They tried out an apparatus of thermodynamics and kinetics of plastic flow new for the glassy state and showed that for glassy polymers two mechanisms of plasticity exists below Tz. The low temperature mechanism in its kinetic patterns is similar to dislocation plasticity in crystals and the high temperature mechanism is connected with the mobility and possibly the free volume of the polymer.

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G. Ii and R. Pearson (General Electric, USA) considered the mechanism of deformation of epoxides modified by rubbery particles. Their results indicate that the fundamental basis of the mechanism of ordering is the presence of a sufficiently large volume of rubber above and below the plane of the growing crack. Such material promotes the development of plastic flow in counterbalance to the rapid growth of the crack. E. Kramer (Cornell University, USA) considered the special aspects of craze formation in polymer glasses. In this work the author showed that an important factor determining the stability of the craze is the volumetric fraction of fibrils in the craze which is linked with the development of the molecular network. L. Nicolais and A, DiBenedetto (University of the State of Connecticut, USA and Naples University, Italy) have examined the kinetics of growth of crazes in thermoplasts. They found that an isolated craze (not interacting with the other crazes) grows linearly with time. The activation parameters of the kinetics of craze growth are defined in the work. J. Wilson and A. Hiltner (Cleveland Institute of Technology, USA) have studied the deformation of the amorphous regions of PE using Fourier IR spectroscopy. They showed that for low deformations both amorphous and crystalline regions orient. Orientation occurs simultaneously in both phases. The determinant criterion for molecular orientation is the true stress at the fluidity limit. The second deformation mechanism acting for high stresses is linked with the conformational changes and slippage of large morphological formations. Among the new methods for studying the structure and properties of polymers we would note the use of synchrotron radiation for studying fast crystallization and orientation processes occurring on deformation of polymers (H. Zachmann, Universitfit, Hamburg, GFR); the development of a new densitometric detector for gel chromatography which is 50 times faster than existing ones; measurement of the MWD of phenolformaldehyde resoles by gel chromatography; and the development of the technique of "trirefringence" for studying orientation in polymer products (R. Samuels, Institute of Technology, State of Georgia, USA). Interesting work o n gel formation of macromolecules was presented by E. Baer (Cleveland Institute of Technology, USA) who examined thermally reversible gel formation (PS solutions), gels of crystallizing polymers (series of chlorinated PE) and also the gel formation of crosslinked polyamino acids. It was postulated that the meshings of the macromolecules are a unique form of structure responsible for gel formation. A current characteristic of work in the field of the structure and properties of polymers is the ever wider use of the latest and most complex physical methods and the endeavour to apply a set of direct complementary methods. The attention of researchers is being attracted by the problems of studying high strength and rigid structures and methods of obtaining them. Microphase separation and interfaces (50 papers). This section proved to be one of the largest at the symposium reflecting the interest in heterogeneous polymer materials. The review paper by I. Sanchoz (National Bureau of Standards, USA) went into the problems of polymer compatibility. He showed that the theory based on the Flory equation of state qualitatively describes all the unusual aspects of the phase behaviour of polymer blends. J. Wendorff (Darmstadt Institute of Plastics, GFR) investigated the thermodynamics and structure of a blend of PMMA and PVDP. It was shown that phase separation passes through the stage of nucleation and growth of spherulites containing both components. The fluctuations in density in the blend are not correlated and are determined by compressibility while the concentration fluctuations are correlated. Partial phase separation occurs in the amorphous region between the PVDP lamellae. R. Stein (University of Massachusetts, USA) has used scatter of neutrons, X-rays and light to study blends of amorphous and amorphoerystalline polymers-their structure, compatibility, interactions, morphology and kinetics of phase separation. W. Prest and F. Roberts (Xerox, USA) have studied the processes of annealing in glassy polymer blends. Using the width of the interval of vitrification a n d the spectrum of the relaxation times found from analysis of the relaxation of thermal capacity the authors obtained information or~ the

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fluctuations in composition in compatible polymer blends. A most interesting phenomenon observed in the work is the widening of the interval of vitrification of a compatible blend during annealing. T. Kivei (Institute of Technology, Taiwan) together with E. Pearce and B. Min (Brooklyn Polytechnic Institute, USA) studying the absorption bands of the hydrogen bonds in polymer blends showed that this method also gives information on microphase separation. D. Feldman (Universit6 Concordia, Montreal, Canada) using polyurethane blends with various vinyl polymers and silicones obtained glues and seals with interesting properties. Stable metal oxide films with good adhesion to the polymer surface (even such as polyolefine and polytetrafluoroethylene) have been obtained by scientists from San Carlos Federal University (R. Baumhardt-Neto et aL, Brazil). The polymer surface was modified by sorbing on it pentacarbonyl iron followed by its oxidation with an aqueous solution of the oxidant. The samples obtained may be used as polymer-metal oxide composites and also as applied catalysts in which the catalytic activity of the oxide is not inferior to that for the free oxide. B. Ratner (University of the State of Washington, USA) studied the chemical and morphological changes no ~xtraction of the surface of commercial polyurethane under in vitro conditions used for biomedical purposes for endoprostheses. The author found that extraction leads to change in the surface morphology apparently through washing out of the low molecular weight products and, therefore, the material for biomedical purposes must be first subjected to extraction treatment. Interesting results have been obtained by P. Waters (Washington University, USA). He found a way of rapidly (almost instantly) obtaining dilute solutions or gels of high concentration for macromolecules of very high M. The polymers were ground in a mill at the temperature of liquid nitrogen and transferred to the solvent in a nitrogen atmosphere. Complete dissolution of the polymer occurs in several seconds. Under the microscope the elastomer particles ground in cryogenic conditions with M = 10~ are seen to swell at room temperature very rapidly while usually the swelling of a sample of this polymer takes several days. For this completely new phenomenon which will undoubtedly find practical application the author proposes an explanation connected with the formation of radicals on the surface, of degradation during cryogenic grinding both by further conversions and interaction of these radicals with the medium during dissolution. S. Desper et aL from the US Army Materials and Mechanics Scientific Centre investigated the structure of polyphosphazenes and demonstrated the presence in them of mesomorphie structures the number and form of which in the sample are determined by the conditions of preparation. Photoelectronic X-ray spectroscopy has been used by E. Merrill, N. Maxmud and S. Wan (Massachusetts Institute of Technology, USA) to study the surface of segmented polyurethanes. They showed that the structure and composition of the surface depend on the solvent from which the sample was prepared. However, as a rule, in preparing the sample from solution the surface is enriched with "soft" segments (polyester component). The degree of enrichment depends on the structure of the "hard" segments (isocyanate-diamine), the lengths of the chain of soft segment and type of solvent. The results are of great importance for biomedical applications of segmented polymethanes. A careful investigation has been made in the same Institute into the surface chemistry of low density PE by radioisotope analysis, electron spectroscopy for chemical analysis (e.s.c.a.) and fluorescence. The work showed that the chemical composition of the surface influences certain macroscppic properties of the samples. A. Shultz (Research Centre of General Electric, USA) devoted his paper to an analysis of plasticized surfaces using for this purpose a wide range of modern physical methods. In particular, he measured the properties o~ the surface of polycarbonate on diffusion into the polymer of additives absorbing UV-light (2-hydroxy-4-dodecyloxybenzophenone). K. Frisch, G. Frisch and others (University of Detroit, USA) reported on the application of the principles for obtaining mutually penetrating meshes for improving the compatibility of polymers. Composites based on the polyurethanes and epoxides were used as examples. T. Furukawa, K. Mittal and G, Aperson (WM, USA) used the spectroscopy of inelastic tunnel-

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ling of electrons to study polymer adhesion and obtained interesting new results on the chemistry and composition of the components of the adhesive on the surface. D. Meier (Midland Macromolecular Institute, USA) considered the deformation processes in block-copolymers and filled systems. Usually, the peculiarities of the behaviour of block-copolymer systems (raised viscosity of melts, raised modulus) are related to the special behaviour of the "meshings" in them. The authors developed a theory which helps to explain many phenomena without resort to special aspects of the "meshings". The analysis is based on notions of the domain morphology of such systems. The model may be extended to filled composites. S. Krause (Rensselaer Polytechnic Institute, USA) investigated Tg of block-copolymers as a function of the length of the blocks. She was able to show that Tg in block-copolymers does not depend on the length of the block in the way to be expected from analysis of homopolymers. The jump in thermal capacity Cp (T~) also appreciably differs from that for the corresponding homopolymers. The author explains this by the interaction of the phases of different composition. The well known specialist in research into polymer surfaces D. Clarke (Durham University, England) devoted his paper to the methods of producing different polymer surfaces and study of their properties. Thus, ultra-fine polymer, surfaces on supports may be produced by plasma methods using the procedures devised in the e.s.c.a, technique. Using this method Clarke studied the chemical changes on the surface of polymers on their natural ageing, on interaction with a liquid and in other conditions. Subtle chemical investigations of polymer surfaces are giving ever newer results thanks to the use of the latest physical methods of investigation. As is clear from the papers, the thermodynamic and kinetic picture of the formation of polymer blends is now qualitatively clear. Therefore, the quantitative description of the phenomena of blending and phase separation now becomes important and, what is particularly important, the links between the structure and composition of the phases in polymer blends and the microscopic properties of the latter. Diffusion phenomena (45 papers). This section touched on a wide range of problems: diffusion of macromolecules in solutions and melts, the effect of pressure on diffusion, diffusion in crystallizing and filled polymers, diffusion of low molecular weight substances (primarily water) in polymers and composites, diffusion in polymer glasses, problems of phase separation, diffusion across membranes and the behaviour of macromoleeules close to the interfaces. J. Klein and D. Fletcher (Cavendish Laboratory, Cambridge, England) investigated the diffusion of stellate polymers in solution of linear macromolecules of the same chemical structure and showed that the reptation mechanism of diffusion also holds for branched structures and the predictions of theoretical models on the dependence of the diffusion coefficient D on the molecular mass are well fulfilled. H. Silleseu (Universitfit Mainz, GFR) has studied the movements in polymer melts by the N M R method. Very rapid local movements were found in the PS melt allowing completely isotropic reorientation of the segments of the size of 10 skeletal bonds. This new process has a wide spectrum of correlation times (4 orders). The reorientation of the phenyl nuclei of PS occurs even 3-5 times faster. Over half all the phenyl nuclei undergo rapid jumps by 180 ° about the axis. It is significant that such "jumps" are not frozen out on vitrification of the polymer. The author was also able to observe a certain role of the network mesh in the processes of self-diffusion of polymers. The technique of correlation photon spectroscopy was used to study diffusion in solution (T. Nose and K. Tanaka, Tokyo Institute of Technology, Japan). They showed that the diffusion of the macromolecules is well described within the framework of the scaling concept and represents translational or internal movements of the polymer coils with the meshings. G. Cauche and K. Joule (Laussane Polytechnical Institute, Switzerland) studied an interesting aspect of diffusion- diffusion of the macromolecules during the healing of cracks. The authors consider that healing is associated with the formation of molecular meshes in the zone of the crack and their formation is connected with the macromolecular diffusion. To observe self-diffusion they devised a special technique of IR spectroscopy. S. Prager and M. Tirell (University of Minnesota,

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USA) presented a theory of union of two polymer surfaces (for example, healing of a crack) in terms of diffusion of the macromolecules through the zone of rupture (separation). T. Ito et al. (Kyoto Institute of Technology, Japan) have investigated the influence of pressure on the diffusion of organic compounds into polymers. The main object of the work was to compare the activation volume of diffusion A V with lhe size of the diffusing particles. Although A V always increases with the volume of the diffusing molecule, the first is always appreciably smaller than the second. The sorption of water by PMMA (D. Turner, University of North Carolina, USA) and polyester sulphone (E. Cole et aL, Coventry Polytechnic, England) gives the interesting effect of systematic rise in durability on creep for damp samples. In connexion with the problems of polymer technology L. Duda and J. Vrentas (University of Pennsylvania, USA) undertook work on molecular diffusion of solvents in polymer melts. Using the free volume concept they were able to describe quantitatively the problem concerned. In their view, the free volume approach has good predictive possibilities. We would note that the problems of migration of low molecular weight compounds in polyolefines and glasses were the subject of many papers. Study of the diffusion of vapours in PVC, PS and PMMA powders showed that at low concentration of,the diffusant neither the chemical nature nor the polarity of the small molecules, nor their capacity to interact with the polymer influence the dependence of D on the size of the diffusant molecules. This means that in such conditions geometric factors dominate. At a high concentration of the diffusant vapours an essential role is played by swelling controlled by relaxation processes in the polymer. An unexpected result was obtained in study of the sorption of water by PMMA (D. Turner, University of North Carolina, USA). It turned out that the crosslink of the macromolecules apparently with the appearance of macropores increases the amount of sorbed moisture. There has been noticeable increase in interest in the problems of sorption and diffusion in composite m e d i a - filled systems, polymer blends, interpenetrating meshes. G. Davis (University of Minnesota, USA) theoretically examined the problems of transport in composite media. The analysis showed that morphological disorder in the system always leads to memory effects, i.e. the effective diffusion coefficient becomes dependent on the time of the experiment. R. Carbonell (University of California, USA) looked at diffusion and thermal conductivity in spatially periodic systems choosing them as models of multiphasic and porous media. In the author's view the method of analyzing periodic systems allows one to consider practically important eases for complex polymer objects. Diffusion in multicomponent polymers was the subject of the paper by A. Kreitus (Institute of Wood Chemistry, U.S.S.R.). A number of studies dealt with the transport of gases through polymer films as a function of the chemical structure of the latter. Here we would note the work of R. Light and R. Seymour (Eastman Kodak, USA) who have established correspondence between the local molecular movements in amorphous polymers and the transport of such gases as 02 and CO2. Study of diffusion processes in polymers and composites is of special interest to researchers of companies, which indicates the importance of these problems for the technology of polymers and the stability of the properties of polymer products in time. For filled composites and fibre-reinforced plastics apparently of the utmost interest are the problems associated with the diffusion of moisture in the polymer matrix and at the interfaces in the comp6site. Rheology (44 papers). The work of the section began with the paper by G. Baird (Polytechnic Institute and University of the State of Virginia, USA) dealing with the flow of the melt of thermotropic liquid crystalline polyesters. Interest in this problem is due to the unique mechanical properties of the fibres and cast samples of liquid crystalline polymers. The author studied the nonlinear viscoelastic response of a copolymer (60 ~op-hydroxybenzoic acid and PETP) on shear. The time-dependent response of this system was determined although attempts to construct a rheological equation of state of liquid crystalline systems have so far been unsuccessful. M. Doi (University of Sategai, Japan) also considered the rheological behaviour of concentrated solutions of rod-shaped

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polymers. The aim of the work was to obtain a constitutive equation of the state of such systems based on the molecular-kinetic theory. It was found that the theory predicts the appearance of a maximum in steady viscosity when the concentration of the polymer in solution reaches a critical concentration (the concentration above which the isotropic phase becomes unstable is considered critical). This conclusion is confirmed by the experiment. The shear modulus for the function of concentration in the region of high elasticity has two maxima: one refers to the isotropic phase and the other to the liquid crystalline phase. D. Baird presented a further study concerning the nature of the meshings in rod-shaped molecules. The results allowed the author to consider that the meshings in the systems constructed from rod-shaped macromolecules do not appreciably differ from those in the usual flexible chain polymers. However, for heavy deformations all the rod-shaped m a c r o m o l e c u l e s orient and the meshings "uncouple" which leads to behaviour of liquid crystalline systems not characteristic of the flexible chain polymers. P. Fuoss et al. (University of Connecticut, USA) to measure the minor differences in the theological behaviour of the samples devised a special method of differential rheometry which gives good results. P. Wang (Institute ef Chemistry, Chinese Acad. Sci., Peking) used the Doppler effect to measure the distribution of the rates in flow of a polymer liquid through a rectangular slit. V. Oppermann, G. Rehage and D. Wagner (Claustal Hochschule, GFR) investigated the rheological behaviour of solutions of PMMA of different microstructure and showed that on exposure to shear stresses the behaviour of the solution is influenced by the intermolecular associations which appear even in solutions of extremely low concentration. H. Winter and K. Wei (University of Massachusetts, USA) studied the morphology of a polymer appearing on contact of two melts. Such a situation is realized on "welding" of two polymers and is of great practical importance. They found that at the interface of two polymers very high orientation appears and the oriented region has appreciable thickness. R. Prud'homme and V. Richards (Princeton University, USA) studied concentrated solutions at high temperatures (450°C) and pressures (up to 31"6 kG/cm 2) and designed the necessary apparatus for these purposes. W. Schowalter (Princeton University, USA) proposed that the activation kinetic theory be used to describe the special features of the flow of polymers close to a rigid wall and obtained results consistent with the experiment. G. Monstedt (Research Centre of BASF AG, GFR) considered the rheology of the polymer melt containing rubbery particles. The work deals with the special aspects of the behaviour of the extrudate as a function of the concentration and particle size of the rubbery phase. The experimental results point to the important role of the macrostructure formed by the rubbery particles. Only the destruction of this macrostructure allows molecular mobility in the matrix necessary for flow. Related problems of the flow of filled polymer systems were examined by L. Kosinski and J. Caruthers (Purdah University, West Lafayette, USA). Measurements of the rheology of the system quartz-polydimethyl siloxane gave much practically useful information. The special aspects of the flow of polymer systems with suspended inclusions were also considered by the well known Japanese specialist S. Onogi (Kyoto University, Japan) who offered an interpretation of all the characteristic features of the flow of such systems. Reactive polydimethyl siloxane filled with silica has been used by American scientists to encapsulate semiconductor products. R. Graessly et al. (Institute Curie, Centre Universitaire, France) studied the transition of the macromolecules on flow of the solution from the coil state to the elongated form in presence of a longitudinal flow elongation gradient. He was able to observe the transition predicted theoretically by de Gennes using for this the technique of localized flow birefringence. An unusnal result concerning the orientation behaviour of PS was obtained by L. Monnerie (Ecole Superieur de Physique et de Chemic, Paris, France). The ability of PS films to orient was studied by the method of IR dichroism and polarized luminescence (for macromoleeules with a luminescent label). IR dichroism made possible quantitative analysis of the local orientation of the

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F. S. D'YACHKOVSKIIand E. F. OLEINIK

chains as a function of temperature and shear rate. It was found that the orientation behaviour of the long macromolecules depends on the molecular weight of the matrix surrounding the macromolecule (orientation rises with change in the molecular weight of PS) which cannot be interpreted on the basis of the current concepts of relaxation. R. Mendelson (Monsanto Plastics, USA) made rheological measurements for a number of constructional thermoplasts based on polycarbonate, polysulphone and polyarylates. The behaviour of the melt of such polymers is of interest since all these polymers have high T~. One of the observed features of the behaviour of such systems was the closer dependence of viscosity on M as compared with flexible chain polymers (exponent 5.0-5"2 instead of 3"4). The author relates this result to the raised intra-chain rigidity. D. Crater and J. Curule (University of North Carolina, USA) considered the special aspects of the flow of the PETP melt leading to the formation of high strength fibres. The work of this section showed that the attention of scientists is now most attracted by two groups of rheological problems: flow of melts of liquid crystalline polymers and the rheological behaviour of heterophase systems, polymer blends and composites. There is no doubt this interest is linked with applied problems in the sphere of new materials. Rigid rod-shaped polymers (37 papers). This section went into many aspects of the synthesis, properties and structure of liquid crystalline polymer systems. The well known specialist in this field A. Blumstein (Lowell University, USA) presented two reports. In one he discussed the properties of thermotropic polyesters with a mesogenic "skeleton'" separated by long sequences of methylene groups, the influence of the structure and geometry of the flexible linkage on the temperatures and interval of the transition. The other report examined the influence of the molecular weight on certain properties of polymer liquid crystals. The paper by V. Jackson (Eastman Kodak, USA) was concerned with the influence of the composition and content of the naphthalene nuclei on Tm~, of some aromatic liquid crystalline polyesters. The introduction of flexible aliphatic groups into liquid crystalline polyesters shortens the relaxation times while the introduction of rigid "breaks" into the chain leads to lessening of orientation. Variations in the concentration of the different fragments in the chain reduce the capacity for the formation of liquid crystals and with it the level of rigidity and the strength in the plastics and fibres of these polymers. H. Ringsdorf and R. Lenz and others have studied mobility in spin-labelled liquid crystalline polymers. They found that the parameters of order of these polymers are comparable with those for liquid crystals of low molecular weight. However, in contrast to low molecular weight liquid crystals the nematic order in polymers may be frozen at T~. No change in the parameters of order were observed in the course of a year on storage of the samples below Ts (at room temperature). In all. the systems studied local order does not depend on the molecular weight of the polymer. However, this is not so for the processes of packing (macrostructure). V. Frosini (Pisa University, Italy) studied the processes of mechanical relaxation in polymer mesophases. He found certain new effects in connexion with the molecular packing and degree of order in the systems studied. The rigidity of the macromolecules forming the polymer mesophases is due, in his view, to the aperiodic helical packing of the side groups about the main chain. Such a cylindrical body may display additional bending or torsional modes of vibrations manifest in the spectrum of mechanical relaxation in the form of rise in the temperature of the beta transition and increase in the relaxation times. V. Welsh, J. Mark and D. Baumic (University of Cincinnati, USA) made a theoretical analysis of some cis- and trans-polybenzo-bis-oxazoles and poly-benzo-bis-thiazoles by the methods of quantum chemistry. They calculated the conformations and electron structure of these polymers. I. Wematsu et aL considered cholesteric nematic transitions in polypeptide liquid crystals anti also in copolymer polypeptides. D. Chen et aL (University of Massachusetts, USA) have begun systematic studies of the ~dbra-

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tory spectra of some fibres of rigid chain polymers including Kevlar. Their aim is to establish the link between the parameters of the vibratory spectrum (IR, c.l.s.) and the conformation and packing of the chains of these polymers in the solid state. Already the first measurements helped to reveal the special aspects of the deformation behaviour of such systems due to the structure of the morphological planar formations bound by hydrogen bonds. Very interesting applications of rod-shaped polymers in molecular composites were proposed by American scientists from the US Air Force Laboratory (Dayton, Ohio), (see section "Composites"). The work of this section shows the considerable activity of scientists in the field of the liquid crystalline state of polymers and in the very near future one may apparently expect new advances here. Viscoelasticity (39papers). This section consisted of two parts. The second part of its work constituted a symposium in honour of the well known scientist-John Ferry. P. Pechhold (Universitht Ulm, GFR) presented an analysis of pliability in amorphous polymers. This analysis is based on the meander model of structure devised by him. The deformation of such a structure is described in the context of the movement of the dislocations. Such an approach helps to explain the appearance on deformation of polymers of shear bands. The model gives good quantitative agreement with the experiment. The well known specialist in the field of mechanical behaviour of polymers S. Sternstein (Renssellaer Polytechnic Institute, Troy, USA) analysed the viscoelastic characteristics of the matrices in bulk and composite. Analysis of the data on the viscoelasticity as a function of temperature, frequency and moisture led the fi.~hor to conclude that the epoxide matrix in the polymer and bulk behaves the same: their aggregate pliability curves fit. The sole difference is that the point of the glass transition is down by 12 ° for the matrix in bulk as compared with the composite. Much interest continues to be shown among scientists in the kinetic and thermodynamic aspects of vitrification of polymers. Arguments continue although most researchers incline to the view that the true thermodynamic transition exists in glasses at the temperatures /'2, the manifestation of which in the experiment is complicated by the action of kinetic factors most clearly in evidence close to T~. Investigators under the direction of S. Onogi (Kyoto University, Japan) have examined the manifestation of non-linearity in crystalline polymers. It is commonly considered that the cause of non-linearity is the sliding of the crystallites in the lamellae. However the authors of the present work in study of PETP with different degree of cyrstallinity showed that characteristic non-linearity shows up in samples with a different morphology-spherulite and fibrous. From this it follows that sliding of the crystallites cannot make the expected contribution. The authors relate the possible mechanism of non-linearity to the mechanism of uncovering of the cracks as a result of which orientation appears. G. Kantov et aL (Universitht Freiburg, GFR) studied the viscoelasticity of donor-acceptor polymer systems based on the monomers of methacryloyl-fl-hydroxyethyl-3,5-dinitrobenzoate (acceptor) and N-(2-hydroxyethyl) carbazolyl methacrylate (donor). The dynamic mechanical properties measured in blends of these polymers showed that interactions of the charge transfer type play an essential role in their structure and behaviour. In particular, such interactions raise Young's modulus. S. Bettu et aL of Florida University (USA) followed change in the spectra of mechanical and dielectric relaxation on deformation of the polymers. Changes were found in the relaxation spectra and it is assumed that these chan~es are the basic cause of the non-linear deformation of polymer glasses. The dynamic properties of statistically deformed polymers were examined by E. Meinecke (Akron University, USA). He found changes in the dynamic storage modulus and losses at different points of the deformation curve and looks at the possible causes of these changes. A new concept of the "energetic kinetic mesh" was introduced by J. Ibar (Laboratoire Solomat, France) to explain the viscoelastic properties of deformed rubbers.

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F. S. D'YACHKOVSKIIand E. F. OLEINIK

O. Zachler (Hercules Research Centre, USA) has elaborated a device for measuring the viscoelastic characteristics during extrusion of a polymer. This allows one to control and finely direct polymer processing. T. Smith (IBM, USA) has studied the time-dependent properties of deformed polymer glasses. He found that the transport of gases through polycarbonate and PS films appreciably changes on deformation. The rate of relaxation of the gas permeability and the diffusion coefficient of argon -and xenon fails with temperature and increases with deformation and the molecular dimensions of the gas. The work of the section showed that as well as the classical investigations in the field of viscoelasticity of polymers growing attention is being paid to the molecular mechanisms of these processes .especially in polymer glasses. Coulomb interactions (35 papers). Ion-containing polymers are attracting increasing attention both of theoreticians and practitioners. With each day the areas of application of ion-containing polymers noticeably widen. Much interest is now being shown in new materials the presence of strong,ly interacting ions in which makes one look forward to improvement of some of their properties. G. Broze et aL (Universit~ de Liege) have begun to develop new ionomers- telechelic polymers ~of the type ( - O O C - P x - C O O - M + + - ) n where P~ is polydiene or PS. Study of these polymers indicates a number of uncommon properties. Thus, the deformation properties in the solid state ~siguificantly depend on the presence of ionic multiplets and the degree of their dissociation. The presumed applications of such systems are linked with their capacity for reversible gel formation, rheothinning, their good adhesive properties and impact strength. Some of these properties are also 'shown by newly synthesized ion-containing polymers butadiene-_st,yrene-N-isobutoxymethylaerylamide (joint work of the scientists of Celanese Plastic and Akron ~.lniversity, USA). A. Eisenberg (McGill University, Canada) looked at the problems of the compatibility of polymers through Coulomb interactions. To increase the mixing entropy of polymers in his view it is necessary to introduce into the polymers to be combined small amounts (1-10 %) of strong proton donors into one polymer and strong proton accepters into the other. Some examples studied by the .author show that such a procedure actually increases compatibility and is of a general character. The general problems of the structure of ionogenie polymers were reviewed by V. McKnight .(University of Massachusetts, USA). Electron microscopy did not reveal morphological structures ~of the ion clnster type. However, small angle neutron scatter of polypentamer sulphonate ionomers Jn presence of moisture indicates the morphology with phase separation. M. Pineri et al. (Centre de Recherche Nucleaire, Grenoble) studied a number of solid ion-containing polymers with statistical distribution along the chain of monomers with ionic groups. The use of M6ssbauer spectra, small angle neutron scatter and ESR points to phase separation (polarnonpolar components) in such systems. A. Hopfinger (Cleveland Institute of Technology, USA) showed that phase separation of the type indicated above is a thermodynamically advantageous process. Interesting results were presented by N. Ise (Kyoto University, Japan) who found that the ~aaacromolecular ions and eharged polymer latexes form ordered structures in solution. X-ray and light ray scatter directly point to the formation of periodic lattices in such systems. W. Risen (Brown University, Providence, USA) made a spectral study of the ionic interactions in ion-containing polymers. He found that in the far IR region of this spectrum absorption bands appear associated with the movement of cations in relation to their surroundings. The presence of these bands enabled the author to detect changes in the interaction between cation and surroundings as a function of the conditions. K. Hnang et aL (University of Wisconsin, USA) found that in segmented polyurethane ionomers with rise in the degree of ionization the glass transition point of the soft segments falls with increase i n Young's modulus and lessening of elongation at rupture of these polymers. Studying the behaviour of ionomers based on polyisobutylene J. Kennedy et aL (Akron Univer:sity, USA) found that clustering of the ions in the polymer significantly influences many of their

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physica' properties and structure. The domains act as physical crosslinks in the material. M?ny problems of the structure and properties of ionomers are still far from solved. Howevel world laboratories are very active in this very wide field and in the very near future one may expect new remits and what is particularly important new materials. Analysis of the themes of the XXVIIIth IUPAC symposium on macromolecules shows that the spectrum of interests of polymer science continues to widen. In the field of fundamental problems a deeper insight into the problems of structure and properties of polymers is being gained aimed at providing a modern physical interpretation of such important properties as eleetricaJ, mechanical and thermal. In all these directions one is struck by the widening application of most modern methods of measurements and approaches characteristic of solid body physics. Research is being particularly actively pursued in the field of material science problems. The synthesis of new polymers, the development of complex heterogeneous materials for constructional and biomedica ! purposes, the development of the theory and methods of obtaining polymer compositional materials are all problems on which the attention of researchers is now focused. Considerable interest is also being shown in the production and investigation of macromolecular structures with maximal orientation. Translated by E. SEMERE

PolymerScienceU.S.S.R.Vol.26, No. 2, pp. 495-497, 1984 Printed in Poland

0032-3950/84 $10.00+ .00 © 1985 Pergamon Press Ltd.

MIKHAIL MIKHAILOVICH KOTON (On his 75th Birthday)* WITH a record of 55 years scientific teaching and public activity Mikhail Mikhailovich Koton, corresponding member of the U.S.S.R. Academy of Sciences and Director of the Institute of High Molecular Weight Compounds, U.S.S.R. Academy of Sciences, celebrated his 75th birthday in December.1983. M. M. Koton is a well known scientist in the field of organic and meta lie-organic chemistry and high me lecular weight compounds. Over 470 published scientific studies and 83 invention patents testify to the wide range of his scientific interests. One of the important lines of scientific research undertaken by M. M. Koton at first under the direction of Academician G. A. Razuvayev and then independently with his colleagues is work in the field of metallo-organic compounds. He synthesized a large number of organic mercury, lead and tin and also thalium, bismuth, antimony and arsenic compounds, many of them for the first time. They formed the basis of wide investigations of the reactivitY'of metallo-organic compounds in various chemical reactions. The culmination of these investigations was his defence in 1945 of a doctoral dissertation. Later, working in the Leningrad Pbysico-Teehnical Institute, U.S.S.R. Academy of Sciences (LPTI), M. M. Koton carried out a series of studies on the synthesis and polymerization of organosilicon compounds. In the LPTI M. M. Koton et al. undertook research widely known in our country and abroad into the synthesis and polymerization of a wide range of substituted styrenes (halogenated styrenes, methyl styrenes, alkoxystyrene, nitro- and amino styrenes, etc.) to study the effect of the chemical structure of the starting monomers on their capacity for polymerization and their thermal * Vysokomol. soyed. A26: No. 2, 443--444, 1984.