Synthesis of graft copolymers and investigation of their properties—II. The sizes, configurations and optical properties of methylmethacrylate-styrene graft copolymer macromolecules

Synthesis of graft copolymers and investigation of their properties—II. The sizes, configurations and optical properties of methylmethacrylate-styrene graft copolymer macromolecules

Abstracts 585 reached, following which the polymerization ceases. No region of acceleration was observed, characteristic of acrylic a n d methacryli...

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Abstracts

585

reached, following which the polymerization ceases. No region of acceleration was observed, characteristic of acrylic a n d methacrylic esters. The nature of the reaction kinetics is largely due to the tenfold higher viscosity of the cetyl methacrylate monomer t h a n the methyl methaerylate monomer as well as the greater molecular weight of the former. Hence the rate constants of the elementary reactions of chain growth and termination are by a n order of magnitude lower. The activation energy of chain termination is b y 2-3 kcal higher than that for methaerylic esters with alcoholic chains consisting of 1-4 atoms. The high viscosity of the medium also explains the low initiation efficiency (f=0.14). The chain transfer coefficients at 70 ° were found to be C = 9 . 8 3 × 10-a for the case of carbon tetrachloride and C=20.5 × 10-s for the case of isopropylbenzene. CONCERNING THE USE OF THE THERMOMECHANICAL CURVE METHOD IN POLYMER INVESTIGATIONS

B. Ya. Teitelbaum, T. I. Sogolova and G. L. Slonimskii, Vysokomol. soyed. 4: N o . 12, 1 8 7 9 - 1 8 8 0 , 1962. C~RTAIlg fundamental questions arising in the use of the thermomechanical curve method for polymer investigations have been discussed. The conditionality of the method has been stressed and the dependence of the shape of the curves upon a n u m b e r of factors, including the experimental conditions has been noted. Special attention has been given to the question of the feasibility of studying the thermomechanical properties of powdered specimens. TRANSPORT AND STRUCTURATION PROCESSES IN THE POLYMEROHOMOLOGOUS SERIES OF POLYACRYLIC ACID AND FRACTIONATED GELATIN

V. A. Kargin, P. V. Kozlov, S. Ya. Mirlina, Z. A. Kapralova and P. F. Chebotkerich, Vysokomol. soyed. 4: No. 12, 1881-1886, 1962. MASS transport through a semipermeable membrane during high-voltage electrodialysis and subsequent structuration of the transported particles has been investigated on synthetic polyelectrolytes polyacrylic acid (PA) a n d on gelatin. I t has been shown that in the process of electrodialysis fractionation of the synthetic polyelectrolytes with respect to molecular weight takes place, no subsequent structuration occurring in the transported particles. The molecular weight of the fraction passing through the membrane is limited by the molecular weight of the initial polyelectrolyte, not exceeding in the present case 10,000-15,000. I n the electrodialysis of proteins (for instance gelatin) dispersion takes place with the formation of sub-particulate blocks that are capable of subsequent structuration. Hence the molecular weight of gelatin transported through the membrane is independent of the molecular weight of the initial specimen. SYNTHESIS OF GRA_I~ COPOLYMERS AND INVESTIGATION OF THEIR PROPERTIES-H. THE SIZES, CONFIGURATIONS .AND OPTICAL PROPERTIES OF METHYLMETHACRYLATE-STYRENE GRAFT COPOLYMER MACROMOLECULES

V. N. Tsvetkov, S. Ya. Magarik, S. I. Klenin and V. Ye. Eskin, Vysokomol. soyed. 5: No. 1, 3-10, 1963. THE hydrodynamic (viscosity and diffusion) a n d optical (light scattering and flow birefringonee) properties of solutions of polymers obtained by the grafting of polystyrene chains on polymethylmethacrylate chains have been investigated. I t has been shown that the graft The Publisher will be pleased to quote for the supply of a full English translation of a n y paper abstracted in these pages.

586

Abstracts

copolymer consists of chains ( M ~ 7 × 104) of polymethylmethacrylate (10~o b y weight) onto which are grafted shorter chains ( M ~ 2 × 103) of polystyrene (90~o b y weight). The graft copolymer has a positive optical anisotropy, despite the negative anisotropy of its main component polystyrene. This is explained b y the specific features of the graft structure. SYNTHESIS OF NEW CELLULOSE DERIVATIVES -- XXIH. SYNTHESIS OF CHLOROCELLULOSE AND ITS CONVERSION PRODUCTS. PREPARATION OF AMINO- AND NITROCELLULOSE

A . I . P o l y a k . 3 v a n d Z. A . R o g o v i n , V y s o k o m o ] . s o y e d . 5: N o . 1, 1 1 - 1 7 , 1963. NEW methods for the synthesis of chloro- a n d aminoccllulose have been developed. A new t y p e of cellulose derivatives, nitrilocellulose, was synthesized f o r the first time b y reaction between chlorocellulose and potassium cyanide. SYNTHESIS OF NEW CELLULOSE DERIVATIVES -- XXIV. SYNTHESIS OF A CELLULOSE -POLYACRYLONITRILE GRAFT COPOLYMER AND INVESTIGATION OF ITS PRO' PERTIES

S u n ' T u n , L i Z h u i a n d Z. A. R o g o v i n , V y s o k o m o l . s o y e d . 5: N o . 1, 1 8 - 2 3 , 1963. THE properties of a cellulosc-polyacrylonitrile graft copolymer with varying number of side chains and varying polymerization coefficient of polyacrylonitrile in the side chain have been investigated. I t has been shown t h a t the properties of the graft copolymer are affected not only b y the structure and a m o u n t of p o l y m e r being grafted on, but also b y the mean polymerization coefficient of polyacrylonitrile in the side chain. COPOLYMERS OF UNSATURATED DICARBOXYLIC ACID SALTS AND METHACRYLIC ACID

Y e . V. K u z n e t s o v a n d V. Y e . L o z h k i n , V y s o k o m o l . s o y e d . 5: N o . 1, 2 4 - 2 7 , 1963. THE synthesis has been described of copolymers of the calcium, magnesium a n d lead salts of maleie a n d fumaric acids with methacrylic acid. I t has been found t h a t the incorporation of these salts considerably shortens the induction period and increases the polymerization rate. The resultant polymers v a r y in composition, fractions of lower molecular weight conraining more of the salt residues. I t was also found t h a t cobalt and copper ammonium salts of maleic acid do not participate in the copolymerization process, but are inhibit0rs of the polymerization of methacrylic acid. The copper salt of maleic acid takes p a r t in the copolymerization but greatly hinders the latter. Fumaric salts more readily copolymerize t h a n the corresponding malcic acid salts. HETEROCHAIN COPOLYMERIZATION--I. COPOLYMERIZATION HYDR1N WITH ACETO AND BENZONITRILES

OF

EPICHLORO-

A . A . D u r g a r y a n a n d R . M. B e g i n y a n , V y s o k o m o ] . s o y e d . 5: N o . 1, 2 8 - 3 1 , 1963. AN INVESTIGATION has been started into the copolymerization of compounds with carbon a t o m multiple-bonded with a heteroatom, of compounds with strained rings, containing a heteroatom in the chain, a n d also of the copolymerization of these compounds with vinyl a n d diene monomers, with the objective of preparing heterochain polymers a n d of elucidating the regularities of these reactions. I t has been shown t h a t epichlorohydrin eopolymerizes with aceto a n d benzonitriles. The monomer reactivity ratios have been obtained for the pairs: epichlorohydrin (M1)--acetonitrile (Ms) rl = 4.2 =]=0.4, r I = 0 ± 0.02 a n d epichlorohydrinbenzonitrile (Ms) rl----2"8±0"2, r 2 ~ 0 ± 0 " 0 2 .