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On the additivity of compression in copolymerization
334
Abstracts
pared with experimental d a t a on the dimensions of polyisobutylene and polydimethylsiloxane macromolocu]es in ideal solvents. I t seems t h a t in b e t h cases quasifree rotation exists within the limits of the monomer units, the restriction of robatio~ in ~be chain being due to correlation between conformations of neighbouring units. FLOW BIREFRINGENCE OF POLYBUTYLMETHACRYLATE SOLUTIONS
V. N . T s v e t k o v , S. I s . L y u b i n a , V y s o k o m o l . s o e d i n , h N o . 6, 8 5 6 - 8 6 2 , 1959. TH]~ dynamic birefringenee and intrinsic viscosity have been determined of a number of p o l y b u t y l m e t h a c r y l a t e (PBMA) fractions ( M from 0.06× 10 e to 8-5 × 10e) in benzene and ethyl acetate. I t has been found t h a t the difference i n polarizabilities of the statistical segment of PBMA a~ --as = -- 14 × 10 -25 cma. I n contrast to l~olymethylmethacrylate considerable hindering of rotation around the bonds is observed in the side chains of PBMA, which m a y be ascribed to the interaction of the large ester groups separated b y a methylene group. The degree of straightening out p of the molecular coil of PBMA has been determined, the mean value of p for all fractions being 2.4. ON THE ADDITIVITY OF COMPRESSION IN COPOLYMERIZATION
L . B . S o k o l o v , A . D . A b k i n , V y s o k o m o l . s o e d i n . 1: N o . 6, 8 6 3 - 8 6 4 , 1959. IT has been shown t h a t in the copolymerization of 2-ethoxyethyl-g-ehloroacrylate a n d of glycol di-a-chloroaerylate with methylacrylate, m e t h y l m e t h a c r y l a t e and styrene compression of the system is not a linear function of the composition of the copolymer formed. On the basis of these as well as other d a t a it has been h~ferrred t h a t a d d i t i v i t y of compression in copolymerization is not a general case. FORMATION OF MACRORADICALS IN THE MECHANICAL DESTRUCTION OF VITRIFIED POLYMERS
P . Y u . B u t i a g i n , A . A . B e r l i n , A . E . K a l m a n s o n . L . A. B l y u m e n f e l ' d , V y s o k o m o l . s o e d i n . 1: N o . 6, 8 6 5 - 8 6 8 , 1959. THE meehanodestruetion of inorganic (quartz) and organic (polystyrene, polyethylene) vitrified polymers has been studied b y the method of electronic paramagnetie resonance (ER). The destruction was carried out in a vibration mill a t low temperatures. EFt spectra corresponding to organic maeroradieals and to atoms w i t h free valences on the quartz surface have been found in the disersion products. I n the ease of polystyrene the free radical concentration attains a value of 4.× 101S/g and for quartz 2 × 101Ug. VULCANIZATION OF RUBBER IN THE PRESENCE OF N,N-DIETHYL-2-BENZOTHIAZYL-SULPHENAMIDE AS ACCELERATOR
B . A . D o g a d k i n , O. N . B e ] i a t s k a i a , A . V. D o b r o m y s ] o v a , M. S. F e l d s h t e i n , V y s o k e r n e l , s o e d i n . 1: N o . 6, 8 7 8 - 8 8 8 , 1959. THE vulcanization of rubber in the presence o f N,N-diethyl-2-benzothiazylsu]phenamide is characterized b y an S-shaped curve with an initial induction period of reaction. The activation energy of sulphur addition in the intial period is 30 keal/mole, in the main period 14 kcal/mole. Oxygen and peroxides accelerate sulphur addition. No induction is noted in a pure oxygen medium. I n the process of interaction with rubber N, N.diethyl-2-benzothiazylsulphenamide
Abstracts
pared with experimental d a t a on the dimensions of polyisobutylene and polydimethylsiloxane macromolocu]es in ideal solvents. I t seems t h a t in b e t h cases quasifree rotation exists within the limits of the monomer units, the restriction of robatio~ in ~be chain being due to correlation between conformations of neighbouring units. FLOW BIREFRINGENCE OF POLYBUTYLMETHACRYLATE SOLUTIONS
V. N . T s v e t k o v , S. I s . L y u b i n a , V y s o k o m o l . s o e d i n , h N o . 6, 8 5 6 - 8 6 2 , 1959. TH]~ dynamic birefringenee and intrinsic viscosity have been determined of a number of p o l y b u t y l m e t h a c r y l a t e (PBMA) fractions ( M from 0.06× 10 e to 8-5 × 10e) in benzene and ethyl acetate. I t has been found t h a t the difference i n polarizabilities of the statistical segment of PBMA a~ --as = -- 14 × 10 -25 cma. I n contrast to l~olymethylmethacrylate considerable hindering of rotation around the bonds is observed in the side chains of PBMA, which m a y be ascribed to the interaction of the large ester groups separated b y a methylene group. The degree of straightening out p of the molecular coil of PBMA has been determined, the mean value of p for all fractions being 2.4. ON THE ADDITIVITY OF COMPRESSION IN COPOLYMERIZATION
L . B . S o k o l o v , A . D . A b k i n , V y s o k o m o l . s o e d i n . 1: N o . 6, 8 6 3 - 8 6 4 , 1959. IT has been shown t h a t in the copolymerization of 2-ethoxyethyl-g-ehloroacrylate a n d of glycol di-a-chloroaerylate with methylacrylate, m e t h y l m e t h a c r y l a t e and styrene compression of the system is not a linear function of the composition of the copolymer formed. On the basis of these as well as other d a t a it has been h~ferrred t h a t a d d i t i v i t y of compression in copolymerization is not a general case. FORMATION OF MACRORADICALS IN THE MECHANICAL DESTRUCTION OF VITRIFIED POLYMERS
P . Y u . B u t i a g i n , A . A . B e r l i n , A . E . K a l m a n s o n . L . A. B l y u m e n f e l ' d , V y s o k o m o l . s o e d i n . 1: N o . 6, 8 6 5 - 8 6 8 , 1959. THE meehanodestruetion of inorganic (quartz) and organic (polystyrene, polyethylene) vitrified polymers has been studied b y the method of electronic paramagnetie resonance (ER). The destruction was carried out in a vibration mill a t low temperatures. EFt spectra corresponding to organic maeroradieals and to atoms w i t h free valences on the quartz surface have been found in the disersion products. I n the ease of polystyrene the free radical concentration attains a value of 4.× 101S/g and for quartz 2 × 101Ug. VULCANIZATION OF RUBBER IN THE PRESENCE OF N,N-DIETHYL-2-BENZOTHIAZYL-SULPHENAMIDE AS ACCELERATOR
B . A . D o g a d k i n , O. N . B e ] i a t s k a i a , A . V. D o b r o m y s ] o v a , M. S. F e l d s h t e i n , V y s o k e r n e l , s o e d i n . 1: N o . 6, 8 7 8 - 8 8 8 , 1959. THE vulcanization of rubber in the presence o f N,N-diethyl-2-benzothiazylsu]phenamide is characterized b y an S-shaped curve with an initial induction period of reaction. The activation energy of sulphur addition in the intial period is 30 keal/mole, in the main period 14 kcal/mole. Oxygen and peroxides accelerate sulphur addition. No induction is noted in a pure oxygen medium. I n the process of interaction with rubber N, N.diethyl-2-benzothiazylsulphenamide