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Vulcanization of rubber in the presence of n,n-diethyl-2-benzothiazyl-sulphenamide as accelerator
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
335
is reduced to mercaptobenzothiazole and cliethylamine, the rate of formation of captax showing a maximum, corresponding to the time of m a x i m u m rate Of vulcanization. A mechanism has been proposed for the accelerating effect of N,N-diethyl-2-benzothiazylsulphenamide, explaining the particular shape of the kinetic curves. A S T U D Y OF T H E R A T E OF O X I D A T I O N OF P O L Y S A C C H A R I D E S NEOUS M E D I U M
V. K . B u i a n o v a , A. A. K o n k i n , V y s o k o m o l . s o e d i n , l :
IN A N H O M O G E -
N o . 6, 8 8 9 - 8 9 3 , 1959.
The effect of the composition and structure of polysaccharides on the rate of their oxidative destruction in alkaline medium has been investigated. As objects of study cellulose, amylose, galaktan, laminarin, xylan and algic and pectic acids were taken. The oxidation was carried out in an homogenous medium, oxygen serving as the oxidizing agent. The process was followed by viscosity measurements. The rate eostant of the reactions was calculated and the activation energy determined. I t has been shown that the chemical structure of the polysaccharidcs greatly influences the re,re of their oxidative destruction. I N V E S T I G A T I O N INTO T H E S T A B I L I T Y T O W A R D S H Y D R O L Y S I S OF T I T A N I U M , TIN A N D A L U M I N U M T R I E T H Y L S I L O X A N E D E R I V A T I V E S IN T H E PROCESS OF P O L Y M E R FORMATION
K . A. A n d r i a n o v , A. A. Z h d a n o v , V y s o k o m o l . s o e d i n . 1: No. 6, 8 9 4 - 8 9 9 , 1959. THE stability towards hydrolysis of tris-(triethylsiloxy)aluminum, tetrakis-(triethylsiloxy)tin and tetrakis-(triethylsiloxy) t i t a n i u m has been studied and it has been shown that the most stable is tetrakis-(triethylsiloxy)titanium. REACTIONS OF O R G A N O M E T A L COMPOUNDS W I T H SALTS OF H E A V Y M E T A L S - - H I . REACTIONS OF O R G A N O A L U M I N I U M COMPOUNDS W I T H T I T A N I U M
I. I. B o l d y r e v a , B. A. D o l g o p l o s k , V. A. Kro1, V y s o k o m o l . s o e d i m 1 : No. 6, 9 0 0 906, 1959 A STUDY has been made of the products of reaction between organoaluminium compounds AI(C2Hs)3, AI(C2Hs)CI2 and AI(C2Hs) Cl2 and the t i t a n i u m halides TiC14 and TiC1s in an inert solvent in connection with the use of these systems as catalysts in the polymerization of butadiene and isoprene. On interaction between triethylaluminium and t i t a n i u m tetrachloride Al(C2t-Is)2C1, AI(C~Hs)CI2, A1CI~, TiC13 and TiC] s may be found among the products depending upon the initial ratio of the components. Aluminium chloride and, as was shown in our laboratory, ethylaluminium chloride are catalysts inducing polymerization according to the cationic type. T1Ci4 has been found to be reduced only to Ti+S by alkylaluminium halides. The precipitate formed in this case is the brown modification of TIC13. I n the case of ethylaluminium dichloride the precipitate contains an almost equivalent a m o u n t of aluminium chloride. The violet modification of TiC13 is also not reduced by alkylaluminium halides even at elevated temperatures. Triethylaluminium under the same conditions partially reduces TiC13 to TiC]~. Comparison of the rate of interaction between t i t a n i u m tetrachloride and various organoaluminium compounds shown that the reactivity decreases in the series: AI(CaHs)s> AI(C~Hs)~> AI(C2Hs)C12. 22*
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
335
is reduced to mercaptobenzothiazole and cliethylamine, the rate of formation of captax showing a maximum, corresponding to the time of m a x i m u m rate Of vulcanization. A mechanism has been proposed for the accelerating effect of N,N-diethyl-2-benzothiazylsulphenamide, explaining the particular shape of the kinetic curves. A S T U D Y OF T H E R A T E OF O X I D A T I O N OF P O L Y S A C C H A R I D E S NEOUS M E D I U M
V. K . B u i a n o v a , A. A. K o n k i n , V y s o k o m o l . s o e d i n , l :
IN A N H O M O G E -
N o . 6, 8 8 9 - 8 9 3 , 1959.
The effect of the composition and structure of polysaccharides on the rate of their oxidative destruction in alkaline medium has been investigated. As objects of study cellulose, amylose, galaktan, laminarin, xylan and algic and pectic acids were taken. The oxidation was carried out in an homogenous medium, oxygen serving as the oxidizing agent. The process was followed by viscosity measurements. The rate eostant of the reactions was calculated and the activation energy determined. I t has been shown that the chemical structure of the polysaccharidcs greatly influences the re,re of their oxidative destruction. I N V E S T I G A T I O N INTO T H E S T A B I L I T Y T O W A R D S H Y D R O L Y S I S OF T I T A N I U M , TIN A N D A L U M I N U M T R I E T H Y L S I L O X A N E D E R I V A T I V E S IN T H E PROCESS OF P O L Y M E R FORMATION
K . A. A n d r i a n o v , A. A. Z h d a n o v , V y s o k o m o l . s o e d i n . 1: No. 6, 8 9 4 - 8 9 9 , 1959. THE stability towards hydrolysis of tris-(triethylsiloxy)aluminum, tetrakis-(triethylsiloxy)tin and tetrakis-(triethylsiloxy) t i t a n i u m has been studied and it has been shown that the most stable is tetrakis-(triethylsiloxy)titanium. REACTIONS OF O R G A N O M E T A L COMPOUNDS W I T H SALTS OF H E A V Y M E T A L S - - H I . REACTIONS OF O R G A N O A L U M I N I U M COMPOUNDS W I T H T I T A N I U M
I. I. B o l d y r e v a , B. A. D o l g o p l o s k , V. A. Kro1, V y s o k o m o l . s o e d i m 1 : No. 6, 9 0 0 906, 1959 A STUDY has been made of the products of reaction between organoaluminium compounds AI(C2Hs)3, AI(C2Hs)CI2 and AI(C2Hs) Cl2 and the t i t a n i u m halides TiC14 and TiC1s in an inert solvent in connection with the use of these systems as catalysts in the polymerization of butadiene and isoprene. On interaction between triethylaluminium and t i t a n i u m tetrachloride Al(C2t-Is)2C1, AI(C~Hs)CI2, A1CI~, TiC13 and TiC] s may be found among the products depending upon the initial ratio of the components. Aluminium chloride and, as was shown in our laboratory, ethylaluminium chloride are catalysts inducing polymerization according to the cationic type. T1Ci4 has been found to be reduced only to Ti+S by alkylaluminium halides. The precipitate formed in this case is the brown modification of TIC13. I n the case of ethylaluminium dichloride the precipitate contains an almost equivalent a m o u n t of aluminium chloride. The violet modification of TiC13 is also not reduced by alkylaluminium halides even at elevated temperatures. Triethylaluminium under the same conditions partially reduces TiC13 to TiC]~. Comparison of the rate of interaction between t i t a n i u m tetrachloride and various organoaluminium compounds shown that the reactivity decreases in the series: AI(CaHs)s> AI(C~Hs)~> AI(C2Hs)C12. 22*