- Email: [email protected]
Comparative study of highly oriented crystalline and amorphous polymers
578
Abstracts
COMPARATIVE STUDY OF HIGHLY ORIENTED CRYSTALLINE AND AMORPHOUS POLYMERS
V. I . Selikhova, G. S. Marlrova a n d V. A. K a r g i n , V y s o k o m o l . soedin. 1: No. ~, 1214-1226, 1959. A co~TlVl X-ray study has been made of the ordering of polymers in the crystalline and amorphotm statea, as exemplified by highly oriented specimens of polyethylene, gutta pereha, tetrafluorethylene vinylidenefluoride copolymer with 1:4 component ratio, and polyethyleneterephthalate. The amorphous state of the polymers (excepting polyethyleneterephthaiate) was studied on the melts. Contraction and flow of the polymer chains at elevated tempemturm was obviated by the use of rigid sheaths and irradiation of the specimens with ~,-rays from a 60 Co source. An X.ray method for evaluating the degree of order of highly ¢riented films in the crystalline and amorphous states has been given. Calculation have been made of the distribution curves of tri.dimensional ordering sites with respect to the orientation angles and distribution curves of amorphous regions in the chains are determined from the X-ray d a t a . High o~dering has been shown to arise spontaneously in the process of phase transitio~ ON T ] ~
KINETICS OF THE MECHANICAL DEGRADATION OF HIGH POLYMERS
B. V Pay]or, Vysokomo]. soedin. 1: N o . 8, 1227-1235, 1959. THE kinetics of the msohanodestruction of polymers are e~Amlned from the standpoint of disproportionation of the radicals formed. An equation has been derived, eorelating the degree of polymerization with the mean elementary rate connstant of molecular destruction. I t has been shown that with the aid of this equation from the form of the time dependence of the degree of polymerization one may derive a qualitative relationship between the elemeQtary rate constant of destru~ction of a molecule and its length. The correlations have been applied to an analysis of the experimental data on the shearing deetruetion of concentrated polymer solutions in a Mac.Kee cousistometer and on destruetion by means of ultrasonic waves.
STRUCTURAL CHANGES IN ORIENTED CRYST.~LLINE AND AMORPHOUS POLYMERS IN T I ~ SOFTENING TEMPEEATUEE REGION V. I. Selikhova, G. S. M a r k o v a a n d V. A. K a r g i n , V y s o k o m o l . soedin. 1: No. 8, 1236-1241, 1959. AN X-ray study of the structural changes taking place in oriented amorphous polymel~ (polyacrylonitrile, cellulose, propionmethacrylate, a number of synthetic rubbers) has been made over a wide range of temperatures including the the glass temperature and the region of the high elastic state of the polymers. Th~ objective of the study was to compare the structural changeQof oriented crystalline and amorphous polymers in the softening temperature region. Distribution curves of the chain sites with respect to the orientation angles have been plotted. In the case of amorphous polymers it was shown that no structural changes take place in the region of the softening temperatures. Comparison of the amorphous and crystalline polymer structures in th5 softening region showed that only phase transitions lead to spontaneous appearance of high order. THERMAL STABILITY OF THE SULPHONOPHTHALENE-FORMALDEHYDE RESINS KU-5 N. G. Polianskii, V. [. V y s h n e v s k a i a a n d Yu. Mizh-Misl~in, V y s o k o m o l . soe(iin, h No. 8, 1249-1257, 1959. IT has been found that heating the cation exchanger KU-5 in air is accompanied by the evolution of volatile products and decrease in exchange capacit~y and in relative swelling. The
Abstracts
COMPARATIVE STUDY OF HIGHLY ORIENTED CRYSTALLINE AND AMORPHOUS POLYMERS
V. I . Selikhova, G. S. Marlrova a n d V. A. K a r g i n , V y s o k o m o l . soedin. 1: No. ~, 1214-1226, 1959. A co~TlVl X-ray study has been made of the ordering of polymers in the crystalline and amorphotm statea, as exemplified by highly oriented specimens of polyethylene, gutta pereha, tetrafluorethylene vinylidenefluoride copolymer with 1:4 component ratio, and polyethyleneterephthalate. The amorphous state of the polymers (excepting polyethyleneterephthaiate) was studied on the melts. Contraction and flow of the polymer chains at elevated tempemturm was obviated by the use of rigid sheaths and irradiation of the specimens with ~,-rays from a 60 Co source. An X.ray method for evaluating the degree of order of highly ¢riented films in the crystalline and amorphous states has been given. Calculation have been made of the distribution curves of tri.dimensional ordering sites with respect to the orientation angles and distribution curves of amorphous regions in the chains are determined from the X-ray d a t a . High o~dering has been shown to arise spontaneously in the process of phase transitio~ ON T ] ~
KINETICS OF THE MECHANICAL DEGRADATION OF HIGH POLYMERS
B. V Pay]or, Vysokomo]. soedin. 1: N o . 8, 1227-1235, 1959. THE kinetics of the msohanodestruction of polymers are e~Amlned from the standpoint of disproportionation of the radicals formed. An equation has been derived, eorelating the degree of polymerization with the mean elementary rate connstant of molecular destruction. I t has been shown that with the aid of this equation from the form of the time dependence of the degree of polymerization one may derive a qualitative relationship between the elemeQtary rate constant of destru~ction of a molecule and its length. The correlations have been applied to an analysis of the experimental data on the shearing deetruetion of concentrated polymer solutions in a Mac.Kee cousistometer and on destruetion by means of ultrasonic waves.
STRUCTURAL CHANGES IN ORIENTED CRYST.~LLINE AND AMORPHOUS POLYMERS IN T I ~ SOFTENING TEMPEEATUEE REGION V. I. Selikhova, G. S. M a r k o v a a n d V. A. K a r g i n , V y s o k o m o l . soedin. 1: No. 8, 1236-1241, 1959. AN X-ray study of the structural changes taking place in oriented amorphous polymel~ (polyacrylonitrile, cellulose, propionmethacrylate, a number of synthetic rubbers) has been made over a wide range of temperatures including the the glass temperature and the region of the high elastic state of the polymers. Th~ objective of the study was to compare the structural changeQof oriented crystalline and amorphous polymers in the softening temperature region. Distribution curves of the chain sites with respect to the orientation angles have been plotted. In the case of amorphous polymers it was shown that no structural changes take place in the region of the softening temperatures. Comparison of the amorphous and crystalline polymer structures in th5 softening region showed that only phase transitions lead to spontaneous appearance of high order. THERMAL STABILITY OF THE SULPHONOPHTHALENE-FORMALDEHYDE RESINS KU-5 N. G. Polianskii, V. [. V y s h n e v s k a i a a n d Yu. Mizh-Misl~in, V y s o k o m o l . soe(iin, h No. 8, 1249-1257, 1959. IT has been found that heating the cation exchanger KU-5 in air is accompanied by the evolution of volatile products and decrease in exchange capacit~y and in relative swelling. The