- Email: [email protected]
The effect of surface tension on interfacial polycondensation
774
N . V . MIKIIAILOVel al.
(2) T h e effect of r e a c t i o n conditions in t h e o x i m a t i o n o f cellulose d i a l d e h y d e a u d t h e d e h y d r a t i o n o f cellulose d i a l d o x i m e s on the nitrile-group c o n t e n t of t h e resulting cellulose dinitrile has b e e n i n v e s t i g a t e d . T h e m a x i m a l nitrile-group c o n t e n t o f t h e d e h y d r a t i o n p r o d u c t c o r r e s p o n d s to 7 ~ 1 5 - 1 8 . Translated by E. O. PIIILLIPS REFERENCES 1. J. COMPTON, W. H. MARTIN, B. H. W A R D and D. E. THOMPSON, Text. Ind. 117:
138, 1953 2. J. COMPTON, Amer. Dyest. Rep. 43: 103, 1954 3. V. A. KARGIN, Kh. U. USMANOV and B. I. AIKHODZHAYEV, Vysokomol. soedin. 1: 149, 1959 4. Kh. U. USMANOV, B. I. AIKHODZHAYEV and U. O. AZIZOV, Vysokomol. soedin. 1: 1570, 1959 5. G. MONTI~GUDET, Peint. pig. vernis 34: 311, 1958 6. J. COMPTON, W. H. MARTIN, B. H. WARD and R. P. BARBER, Text Res. (J.) 25: 58, 1955; J. N. GRANT, L. H. GREATHOUSE, J. D. REID and J. W. WEAVER, Text. Res. (J.) 25: 76, 1955 7. A. WOHL, Ber. 26: 730, 1893; 32: 3666, 1899 8. G. ZEMPL]~N Bet. 60: 171, 1927; G. ZEMPLl~N and D. KISS, Ber. 60: 165, 1927 9. Yu. S. KOZLOVA and Z. A. ROGOVIN, Vysokomol. soedin. 2: 614, 1960 10. R. T. O'CONNOR, E. F. DU PR]~ and E. R. McCALL, Text. Res. (J.) 28: 542, 1958 ll. L. BELLAMY, Infrakrasnye spektry molekul. (Infra-red Spectra of Complex Molecules.) p. 318, Foreign Literature Publishing House, 1957
THE EFFECT OF SURFACE TENSION ON INTERFACIAL POLYCONDENSATION * N. V. MIKHAILOV, S. S. ~TIKOLAYEVA a n d V. I. MAIBORODA All-Union Scientific-Research Institute of Synthetic Fibre (Received 20 August 1960) D U R I N G the interracial c o n d e n s a t i o n of m o n o m e r s , fibre f o r m a t i o n c a n be a c h i e v e d in a n u m b e r o f w a y s [1]. T h e principle o f t h e m e t h o d s for t h e f o r m a t i o n o f fibres, p r o p o s e d in s o m e U.S. p a t e n t s a n d p u b l i s h e d papers, is b a s e d on t h e f a c t t h a t w h e n . m e t e r e d c u r r e n t s o f t h e m o n o m e r s flow t o g e t h e r in t h e s a m e direction t h e p o l y m e r is p r o d u c e d in t h e f o r m o f a m o n o f i l a m e n t . i n t h e p r e v i o u s c o m m u n i c a t i o n on t M s s u b j e c t [2] we described one o f o u r s u g g e s t e d m e t h o d s o f fibre f o r m a t i o n a n d p r e s e n t e d d a t a on t h e m e c h a n i s m of * Vysokomol. soedin. 3: No. 7, 991-994, 1961.
Effect o f surface t e n s i o n o n i n t e r f a c i a l c o n d e n s a t i o n
775
fibre formation during the interfaeial polyeondensation of polyhexamethylenesebacamide. We pointed out that ff during the reaction, conditions are produced that result in weakening of the interfacial boundary, fibre formation is impaired or completely prevented. I t is well known that surface tension arises at the interfacial boundary, which varies with the conditions. Decrease in the surface tension to a certain limiting value can result in unrestricted mixing of the phases, i.e. to disappearance of the surface of separation. Some authors [3] state that the interracial boundary has no orientating effect on the monomers, b u t as a result of their different solubilities in the two phases the boundary creates conditions for the controlled penetration of the monomers into the reaction zone. The purpose of the present work was to examine the effect of the surface tension at the interracial boundary on th~ process of fibre formation and on the properties of the polymer. In view of the fact that during the determination of surface tension at the boundary between the monomer solutions a film of polymer is formed, which interferes with the determination, it was necessary to determine the surface tension in model systems. The surface tension at the boundaries between "organic solvent-aqueous solution of hexamethylene diamine" and "solution of sebacyl chloride in methylene chloride-water" was determined b y means of a Rebinder apparatus. The results from the measurement of surface tension at the boundary in the first of the above systems are shown in Table 1. TABLE 1. DEPENDENCE OF FIBRE FORMATION ON SURFACE TENSION AT THE "ORGANIC SOLVENT-AQUEOUS SOLUTION OF HEXAMETHYLENE DIAMINE ~ INTERFACE ( A q u e o u s p h a s e : 10o/o h e x a m e t h y l e n e d i a m i n e a n d 5°/o KaCO3) Organic solvent Benzene Methylene chloride Carbon tetrachloride Chlorobenzene Butyl acetate
a ( e r g s / c m 2)
Remarks
30 25.5
F i b r e forrded Fibre formed Fibre formed Fibre formed Floeculent polymer formed Flocculent polymer formed Flocculent polymer formed
:i 11.05 i
10.06 7"08
Ethyl acetate
5"45
Cyelohexanol
3"06
It is seen that fibre formation at the interface occurs only when the surface tension is greater than 7-8 ergs/cm 2. We have already reported [2] that an increase in the hexamethylene diamine: sebacyl chloride ratio results in the production of a coarse-grained, and evidently porous, product. In order to examine the effect of increase in hexamethylene diamine concentration on surface tension the latter was measured at the phase 51 Polymer 5
776
N . V . MIKHAILOV et al.
boundary in the system "methylene chloride-aqueous solution of hexamethyle~m dlamine". The results are shown in Table 2. TABLE 2. EFFECT OF VARIATION IN CONCENTRATION OF HEXAMETHYLENE DIAMINE IN AQUEOUSPHASE ON SURFACE TENSION AND THE FIBRE-FORMINGPROCESS (Organic s o l v e n t - - m e t h y l e n e ehlorido) Concentration of hexamethylene diamine solution (%)
G
Remarks
(ergs/em 2)
1
13"6
10
6.'2
20 40
4.43 1.5
Fibre can be drawn a t room temperature Fibre can be drawn at r o o m temperature Fibre brittle Fibre does not form
These results indicate that an increase in the concentration of diamine produees a decrease in surface tension. This can be explained by an increase in the mutual solubility of the phases, which destroys the surface of separation. In connection with the above results it was of interest to investigate the effect of surface-active agents, added to the aqueous and organic phase?, on the fibre-forming process. For this purpose the surface tension at the interface was measured in the system "solution of sebaeyl chloride in methylene chlorideaqueous solution of hexamethylene diamine" with the addition of various surf a c e - a c t i v e a g e n t s . T h e r e s u l t s a r e s h o w n i n T a b l e 3. TABLE 3. EFFECT OF ADDITIONOF SURFACEACTIVEAGENTSTO THE AQUEOUSPHASE OH THE FIBRE-FORMING PROCESS AND THE SPECIFIC VISCOSITY OF THE POLYMER a* Surface-active agent
Carbozolin- 0 Petrov's " K o n t a k t " Steorox- 6 OS-20
(ergs/cm 2)
1.84 2.25 7:0 14-7
Specific viscosity of a 5~o solution of the polymer in tricresol 0.23 0"20 0"53
0"7
Remarks
Suspension formed Suspension formed Coarse flocculate formed Fibre formed
* At the "sebacyl chloride in CHiCLe-water" interface, with addition of surface-activcagents. The results presented in Tables 1-3 indicate that decreased surface tensiou. leading to gradual disappearance of the interracial boundary, interferes with the process of film or fibre formation and results in the formation of a polymer of decreased molecular weight in the form of a powder or flocculent mass.
E f f e c t o f s u r f a c e t e n s i o n or~ i n t e r r a c i a l c o n d e n s a t i o n
777
When the two monomer phases are completely mixed, for example when b o t h monomers are dissolved in the same solvent (adipyl chloride and hexamethylene diamine in ether) film and fibre formation does not occur and a product consisting of dimer and trimer, in the form of a powder, is obtained. It must be concluded from these observations that the surface tension at the interfacial boundary plays a decisive role in the mechanism of formation of the polymer and fibre. According to the idea first p u t forward b y Langmuir [4] and Harkins [5], the molecules of a material that are on a phase boundary are orientated. The strong field around the polar group or hydrocarbon chain of an organic molecule is independent of the other part of the molecule. It is evident that also in the case of interracial polycondensation the molecules of the monomers with symmetrically situated polar groups maintain a horizontal orientation in the adsorbed layers. I t m a y be assumed that in the case of fibre formation in a rising current of two monomers, where the direction of the currents itself creates a definite Orientation of the diphilic monomer molecules in relation to the axis of symmetry, the polymer molecules formed are also orientated with respect to one another. At the initial stage of dimer formation orientation of the monomers is not a necessary condition for the reaction. Subsequent growth of the chain, brought about b y reaction of the dimer with the functional groups of the monomers, evidently occurs as a result of turning of the ends of the polymer molecule to the aqueous and organic phases alternately because such an arrangement of the active groups will correspond to the minimal free energy. In this case orientation of the growing polymer molecule at the phase boundary must exert a substantial effect on the rate of chain growth. I t is possible also that the process is dependent on the distribution coefficient of the monomers in the layers of the two phases close to the buundary. When the two reacting phases mix, i.e. the surface tension at the boundary is virtually zero, the energy requirements for the monomer molecules to turn to either side are the same. Hence (in the best case) dimers and trimers will be formed. Generalizing from the above considerations it m a y be stated that the formation of a polymer in the form of a continuous film o r fibre during interfacial polycondensation depends to a considerable extent on the surface tension at the interface. The excess free energy of the monomer molecules at the phase boundary is compensated b y the definite orientation of the diphilic molecules relatively to one another. This orientation promotes instantaneous polymer formation in the surface layer, with subsequent chain growth resulting from diffusion of monomer molecules through the polymer film. During the diffusion process the growing chain as it were adsorbs on to itseff the monomer molecules, through the active groups.
51 •
778
D . E . IL'IN.~ et al.
CONCLUSIONS (]) I t is s h o w n t h a t the interracial b o u n d a r y between the m o n o m e r s a n d the surface tension a t the b o u n d a r y affects the fibre-forming process a n d the properties o f the p o l y m e r formed. (2) A n o r i e n t a t i n g effect o f the interfacial b o u n d a r y on the m e c h a n i s m o f p o l y m e r a n d fibre f o r m a t i o n is suggested. Translated by E. O. PIHLLIPS REFERENCES l. U. S. Patent No. 2,708,617, 1955; J. Textile Inst. 47: A176, 1956 2. N. V. MIKttAILOV, V. I. MAIBORODA and S. S. NIKOLAYEVA, Vysokomol. soedin. 2: 989, 1960 3. P. W. MORGAN and K. WOLEK, J. Polymer Sci. 40: 299, 1959 4. I. LANGMUIR, J. Amer, Chem. Soc. 38: 2221, 1916; 39: 1848, 1917 5. W. D. HARKINS, J. Amer. Chem. See. 39: 541, 1917; 42: 700, 1920
THE CHLOROSULPHONATION OF POLYPROPYLENE* D.
E. IL'INA, B. A. K R E N Z E L ' a n d A. V. TOPCHIEV
Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences (Received 24 August 1960) AS WE h a v e a l r e a d y p o i n t e d o u t [1], the chlorinktion a n d chlorosulphonation o f polyolefms is o f considerable theoretical a n d practical interest for the modification o f the properties o f these polymers. I n this connection it seemed profitable to s t u d y some relationshiFs o f the factors involved in the p h o t o c h e m i c a l chloros u l p h o n a t i o n o f p o l y p r o p y l e n e a n d to investigate the properties o f the products.
EXPERIMENTAL Starting materials. In most of the experiments stereoblock polypropylenc of softenh,~ point 168-172 ° and intrinsic viscosity 1.55 (determined in decalin at 120°) was used. We prepared this polymer with the AI(C2I-Is)3+TiC14catalyst system. The amount of amorphous fraction (soluble in boiling ether) was 23o/0. Carbon tetraehloride was used as reaction medium. The chlorosulphonating agent was a mixture of gaseous chlorine and sulphur dioxide of definite composition. Experimental method. Chlorosu]phonation was carried out photochemically in a fournecked, glass flask fitted with a stirrer, a bubbler for introduction of the mixture of chlorine and sulphur dioxide, a thermometer and a reflux condenser. The reaction mixture was illuminated by a 200 W incandescent lamp. The required quantity of polypropylene and carbon tetraehloride was placed in the flask. * Vysokomol. soedin. 3: 2qo. 7, 995-999, 1961.
N . V . MIKIIAILOVel al.
(2) T h e effect of r e a c t i o n conditions in t h e o x i m a t i o n o f cellulose d i a l d e h y d e a u d t h e d e h y d r a t i o n o f cellulose d i a l d o x i m e s on the nitrile-group c o n t e n t of t h e resulting cellulose dinitrile has b e e n i n v e s t i g a t e d . T h e m a x i m a l nitrile-group c o n t e n t o f t h e d e h y d r a t i o n p r o d u c t c o r r e s p o n d s to 7 ~ 1 5 - 1 8 . Translated by E. O. PIIILLIPS REFERENCES 1. J. COMPTON, W. H. MARTIN, B. H. W A R D and D. E. THOMPSON, Text. Ind. 117:
138, 1953 2. J. COMPTON, Amer. Dyest. Rep. 43: 103, 1954 3. V. A. KARGIN, Kh. U. USMANOV and B. I. AIKHODZHAYEV, Vysokomol. soedin. 1: 149, 1959 4. Kh. U. USMANOV, B. I. AIKHODZHAYEV and U. O. AZIZOV, Vysokomol. soedin. 1: 1570, 1959 5. G. MONTI~GUDET, Peint. pig. vernis 34: 311, 1958 6. J. COMPTON, W. H. MARTIN, B. H. WARD and R. P. BARBER, Text Res. (J.) 25: 58, 1955; J. N. GRANT, L. H. GREATHOUSE, J. D. REID and J. W. WEAVER, Text. Res. (J.) 25: 76, 1955 7. A. WOHL, Ber. 26: 730, 1893; 32: 3666, 1899 8. G. ZEMPL]~N Bet. 60: 171, 1927; G. ZEMPLl~N and D. KISS, Ber. 60: 165, 1927 9. Yu. S. KOZLOVA and Z. A. ROGOVIN, Vysokomol. soedin. 2: 614, 1960 10. R. T. O'CONNOR, E. F. DU PR]~ and E. R. McCALL, Text. Res. (J.) 28: 542, 1958 ll. L. BELLAMY, Infrakrasnye spektry molekul. (Infra-red Spectra of Complex Molecules.) p. 318, Foreign Literature Publishing House, 1957
THE EFFECT OF SURFACE TENSION ON INTERFACIAL POLYCONDENSATION * N. V. MIKHAILOV, S. S. ~TIKOLAYEVA a n d V. I. MAIBORODA All-Union Scientific-Research Institute of Synthetic Fibre (Received 20 August 1960) D U R I N G the interracial c o n d e n s a t i o n of m o n o m e r s , fibre f o r m a t i o n c a n be a c h i e v e d in a n u m b e r o f w a y s [1]. T h e principle o f t h e m e t h o d s for t h e f o r m a t i o n o f fibres, p r o p o s e d in s o m e U.S. p a t e n t s a n d p u b l i s h e d papers, is b a s e d on t h e f a c t t h a t w h e n . m e t e r e d c u r r e n t s o f t h e m o n o m e r s flow t o g e t h e r in t h e s a m e direction t h e p o l y m e r is p r o d u c e d in t h e f o r m o f a m o n o f i l a m e n t . i n t h e p r e v i o u s c o m m u n i c a t i o n on t M s s u b j e c t [2] we described one o f o u r s u g g e s t e d m e t h o d s o f fibre f o r m a t i o n a n d p r e s e n t e d d a t a on t h e m e c h a n i s m of * Vysokomol. soedin. 3: No. 7, 991-994, 1961.
Effect o f surface t e n s i o n o n i n t e r f a c i a l c o n d e n s a t i o n
775
fibre formation during the interfaeial polyeondensation of polyhexamethylenesebacamide. We pointed out that ff during the reaction, conditions are produced that result in weakening of the interfacial boundary, fibre formation is impaired or completely prevented. I t is well known that surface tension arises at the interfacial boundary, which varies with the conditions. Decrease in the surface tension to a certain limiting value can result in unrestricted mixing of the phases, i.e. to disappearance of the surface of separation. Some authors [3] state that the interracial boundary has no orientating effect on the monomers, b u t as a result of their different solubilities in the two phases the boundary creates conditions for the controlled penetration of the monomers into the reaction zone. The purpose of the present work was to examine the effect of the surface tension at the interracial boundary on th~ process of fibre formation and on the properties of the polymer. In view of the fact that during the determination of surface tension at the boundary between the monomer solutions a film of polymer is formed, which interferes with the determination, it was necessary to determine the surface tension in model systems. The surface tension at the boundaries between "organic solvent-aqueous solution of hexamethylene diamine" and "solution of sebacyl chloride in methylene chloride-water" was determined b y means of a Rebinder apparatus. The results from the measurement of surface tension at the boundary in the first of the above systems are shown in Table 1. TABLE 1. DEPENDENCE OF FIBRE FORMATION ON SURFACE TENSION AT THE "ORGANIC SOLVENT-AQUEOUS SOLUTION OF HEXAMETHYLENE DIAMINE ~ INTERFACE ( A q u e o u s p h a s e : 10o/o h e x a m e t h y l e n e d i a m i n e a n d 5°/o KaCO3) Organic solvent Benzene Methylene chloride Carbon tetrachloride Chlorobenzene Butyl acetate
a ( e r g s / c m 2)
Remarks
30 25.5
F i b r e forrded Fibre formed Fibre formed Fibre formed Floeculent polymer formed Flocculent polymer formed Flocculent polymer formed
:i 11.05 i
10.06 7"08
Ethyl acetate
5"45
Cyelohexanol
3"06
It is seen that fibre formation at the interface occurs only when the surface tension is greater than 7-8 ergs/cm 2. We have already reported [2] that an increase in the hexamethylene diamine: sebacyl chloride ratio results in the production of a coarse-grained, and evidently porous, product. In order to examine the effect of increase in hexamethylene diamine concentration on surface tension the latter was measured at the phase 51 Polymer 5
776
N . V . MIKHAILOV et al.
boundary in the system "methylene chloride-aqueous solution of hexamethyle~m dlamine". The results are shown in Table 2. TABLE 2. EFFECT OF VARIATION IN CONCENTRATION OF HEXAMETHYLENE DIAMINE IN AQUEOUSPHASE ON SURFACE TENSION AND THE FIBRE-FORMINGPROCESS (Organic s o l v e n t - - m e t h y l e n e ehlorido) Concentration of hexamethylene diamine solution (%)
G
Remarks
(ergs/em 2)
1
13"6
10
6.'2
20 40
4.43 1.5
Fibre can be drawn a t room temperature Fibre can be drawn at r o o m temperature Fibre brittle Fibre does not form
These results indicate that an increase in the concentration of diamine produees a decrease in surface tension. This can be explained by an increase in the mutual solubility of the phases, which destroys the surface of separation. In connection with the above results it was of interest to investigate the effect of surface-active agents, added to the aqueous and organic phase?, on the fibre-forming process. For this purpose the surface tension at the interface was measured in the system "solution of sebaeyl chloride in methylene chlorideaqueous solution of hexamethylene diamine" with the addition of various surf a c e - a c t i v e a g e n t s . T h e r e s u l t s a r e s h o w n i n T a b l e 3. TABLE 3. EFFECT OF ADDITIONOF SURFACEACTIVEAGENTSTO THE AQUEOUSPHASE OH THE FIBRE-FORMING PROCESS AND THE SPECIFIC VISCOSITY OF THE POLYMER a* Surface-active agent
Carbozolin- 0 Petrov's " K o n t a k t " Steorox- 6 OS-20
(ergs/cm 2)
1.84 2.25 7:0 14-7
Specific viscosity of a 5~o solution of the polymer in tricresol 0.23 0"20 0"53
0"7
Remarks
Suspension formed Suspension formed Coarse flocculate formed Fibre formed
* At the "sebacyl chloride in CHiCLe-water" interface, with addition of surface-activcagents. The results presented in Tables 1-3 indicate that decreased surface tensiou. leading to gradual disappearance of the interracial boundary, interferes with the process of film or fibre formation and results in the formation of a polymer of decreased molecular weight in the form of a powder or flocculent mass.
E f f e c t o f s u r f a c e t e n s i o n or~ i n t e r r a c i a l c o n d e n s a t i o n
777
When the two monomer phases are completely mixed, for example when b o t h monomers are dissolved in the same solvent (adipyl chloride and hexamethylene diamine in ether) film and fibre formation does not occur and a product consisting of dimer and trimer, in the form of a powder, is obtained. It must be concluded from these observations that the surface tension at the interfacial boundary plays a decisive role in the mechanism of formation of the polymer and fibre. According to the idea first p u t forward b y Langmuir [4] and Harkins [5], the molecules of a material that are on a phase boundary are orientated. The strong field around the polar group or hydrocarbon chain of an organic molecule is independent of the other part of the molecule. It is evident that also in the case of interracial polycondensation the molecules of the monomers with symmetrically situated polar groups maintain a horizontal orientation in the adsorbed layers. I t m a y be assumed that in the case of fibre formation in a rising current of two monomers, where the direction of the currents itself creates a definite Orientation of the diphilic monomer molecules in relation to the axis of symmetry, the polymer molecules formed are also orientated with respect to one another. At the initial stage of dimer formation orientation of the monomers is not a necessary condition for the reaction. Subsequent growth of the chain, brought about b y reaction of the dimer with the functional groups of the monomers, evidently occurs as a result of turning of the ends of the polymer molecule to the aqueous and organic phases alternately because such an arrangement of the active groups will correspond to the minimal free energy. In this case orientation of the growing polymer molecule at the phase boundary must exert a substantial effect on the rate of chain growth. I t is possible also that the process is dependent on the distribution coefficient of the monomers in the layers of the two phases close to the buundary. When the two reacting phases mix, i.e. the surface tension at the boundary is virtually zero, the energy requirements for the monomer molecules to turn to either side are the same. Hence (in the best case) dimers and trimers will be formed. Generalizing from the above considerations it m a y be stated that the formation of a polymer in the form of a continuous film o r fibre during interfacial polycondensation depends to a considerable extent on the surface tension at the interface. The excess free energy of the monomer molecules at the phase boundary is compensated b y the definite orientation of the diphilic molecules relatively to one another. This orientation promotes instantaneous polymer formation in the surface layer, with subsequent chain growth resulting from diffusion of monomer molecules through the polymer film. During the diffusion process the growing chain as it were adsorbs on to itseff the monomer molecules, through the active groups.
51 •
778
D . E . IL'IN.~ et al.
CONCLUSIONS (]) I t is s h o w n t h a t the interracial b o u n d a r y between the m o n o m e r s a n d the surface tension a t the b o u n d a r y affects the fibre-forming process a n d the properties o f the p o l y m e r formed. (2) A n o r i e n t a t i n g effect o f the interfacial b o u n d a r y on the m e c h a n i s m o f p o l y m e r a n d fibre f o r m a t i o n is suggested. Translated by E. O. PIHLLIPS REFERENCES l. U. S. Patent No. 2,708,617, 1955; J. Textile Inst. 47: A176, 1956 2. N. V. MIKttAILOV, V. I. MAIBORODA and S. S. NIKOLAYEVA, Vysokomol. soedin. 2: 989, 1960 3. P. W. MORGAN and K. WOLEK, J. Polymer Sci. 40: 299, 1959 4. I. LANGMUIR, J. Amer, Chem. Soc. 38: 2221, 1916; 39: 1848, 1917 5. W. D. HARKINS, J. Amer. Chem. See. 39: 541, 1917; 42: 700, 1920
THE CHLOROSULPHONATION OF POLYPROPYLENE* D.
E. IL'INA, B. A. K R E N Z E L ' a n d A. V. TOPCHIEV
Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences (Received 24 August 1960) AS WE h a v e a l r e a d y p o i n t e d o u t [1], the chlorinktion a n d chlorosulphonation o f polyolefms is o f considerable theoretical a n d practical interest for the modification o f the properties o f these polymers. I n this connection it seemed profitable to s t u d y some relationshiFs o f the factors involved in the p h o t o c h e m i c a l chloros u l p h o n a t i o n o f p o l y p r o p y l e n e a n d to investigate the properties o f the products.
EXPERIMENTAL Starting materials. In most of the experiments stereoblock polypropylenc of softenh,~ point 168-172 ° and intrinsic viscosity 1.55 (determined in decalin at 120°) was used. We prepared this polymer with the AI(C2I-Is)3+TiC14catalyst system. The amount of amorphous fraction (soluble in boiling ether) was 23o/0. Carbon tetraehloride was used as reaction medium. The chlorosulphonating agent was a mixture of gaseous chlorine and sulphur dioxide of definite composition. Experimental method. Chlorosu]phonation was carried out photochemically in a fournecked, glass flask fitted with a stirrer, a bubbler for introduction of the mixture of chlorine and sulphur dioxide, a thermometer and a reflux condenser. The reaction mixture was illuminated by a 200 W incandescent lamp. The required quantity of polypropylene and carbon tetraehloride was placed in the flask. * Vysokomol. soedin. 3: 2qo. 7, 995-999, 1961.