942 ELECTRIC AND SOLUTIONS
Abstracts DYNAMIC RIREFRINGENCE
V. N . T s v e t k o v , Y u . V, M i t i n , V. R . G l u s h e n k o v a , A . Y e . G r i s h c h e n k o , N. N . B o i t s o v a a n d S. Y a . L y u b i n a , V y s o k o m o l . s o y e d . 5 : N o . 3, 4 5 3 - 4 5 9 , 1963. THE dynamic and electric birefringenee of solutions o f a poly-?-benzyl-L-glutamate specimen synthesized b y conventional means has been investigated. Determinations were made of the optical anisotropy, dipole moment, lenght and molecular weight of the poly-?-benzyl-Lglutamate molecules in two solvents: dichJoroethane and chloroform. The experimental d a t a for the first solvent correspond to a rigid a-helical conformation of the molecule. Deviation from the properties of a a-helix are observed for solutions in chloroform, which m a y be ascribed both to the effect of association and a certain degree of flexibility of the molecular chains. PHOTOPOLYMERIZATION OF ACRYLONITRILE IN A HOMOGENEOUS MEDIUM
K . S i m i o n e s k u , D. F e l ' d m a n 4 6 0 - 4 6 6 , 1963.
and F. Shandru,
V y s o k o m o ] . s o y e d . 5 : N o . 3,
TItE photopolymerization of acrylonitrile (AN) in dimethylformamide (DMF) and in concentrated ZnC] 2 and ZnCla+CaC]~ solutions in the presence of cerium sulphate, Ce(SO4) ~ . 4HsO, as initiator has been investigated. I t has been found that the degree of conversion of AN is greater in -bhe salt solutions than in DMF. I n the former polymers of molecular weights ~ 400,000 and in the latter only of about 26,000-34,000 are obtained. D a t a have been presented on the change in viscosity of inorganic salt solutions of polyacrylonitrile and of the behaviour of AN at high temperatures. The I R spectrum of polyacrylonitrile has been discussed. LONG-LIFE RADICALS FORMED IN THE y-IRRADIATION OF CELLULOSE
V. N. M a k a t u n , A . K . P o t a p o v i c h 5: N o . 3, 4 6 7 - 4 6 8 , 1963.
and I. N. Yermolenko,
IT HAs been shown t h a t the product of the ?-irradiation of cellulose contains more than one species of long-life free radicals. The radicals are formed b y the action of the radiation on the polymer and not as secondary formations from the active products of radiolysis of adsorbed water. Changes in the E P R spectra of the irradiated cellulose materials due to preliminary oxidation of the cellulose have been observed. CARBANION MECHANISM OF GAMMA RAY INDUCED POLYMERIZATION
L. P . M. z h i r o v a , Z. S m i g a s e v i c h , A. P . S h e i n k e r a n d A . D. A b k i n , V y s o k o m o l . s o y c d . 5 : N o . 4, 4 7 3 - 4 7 8 , 1963. THE effect of temperature on the polymerization rate of acrylonitrile in triethylamine, ethyl chloride, acetonitrile and butyronitrile solutions as well as on the composition of acrylonitrilestyrene copolymers formed under the influence of y-rays has been investigated. The kinetics o f the low temperature radiation copolymerization of acrylonitrile and methyl methacrylate has also been studied and the composition of the resultant copolymers have been determined A t --78 ° acrylonitrile dissolved in triethylamine (electron donor solvent) was found to polymerize, but no polymerization occurred in ethyl chloride, acetonitrile or butyronitrile solution. A t 0 ° acrylonitrile polymerizes at appreciable rates in all the solvents. Acrylonitrile-styrene