B.A. Krentsel

Intramolecular liquid-crystal order in polymers with chain side groups

Abstract Hydrodynamic, optical and electro-optical properties of solutions of polyphenyl methacrylic esters of cetyl and nonyl oxybenzoic acids and of random copolymers of the C 16 ester with cetyl methacrylate have been investigated. Experimental data show that the molecules of these polymers exhibit intramolecular orientationalpolar order of a mesomorphic type in which the side-chains form a mobile liquid-crystalline structure. The intramolecular mesomorphic state is due to the side chain radical containing groups capable of forming thermotropic nematic liquid crystals.

Hydrodynamic and optical behaviour of polyester molecules of alkoxybenzoates and their dependence on molecular weight

Abstract A study of progressing diffusion, sedimentation, viscosity and flow birefringence of phenylmethacrylyl ester fractions of cetyl- (C 16 ) and nonyloxybenzoic acids (C 9 ) in tetrachloromethane indicates that the equilibrium rigidity of the main chain of C 16 ( S = 22) and C 9 ( S = 16) polyester molecules, determined from hydrodynamic results somewhat exceeds the rigidity of molecules of a similar structure but without these side groups. A reduction in birefringence for C 16 and C 9 polyesters with an increase of molecular weight was observed experimentally. This abnormal variation in the optical anisotropy of macromolecules is, apparently, the consequence of a reduction in the orientation order in macromolecular side chains.

Intramolecular order in copolymers of crystal-like molecules

Abstract A study was made of the hydrodynamic characteristics, and of the optical and electrooptical properties of copolymers of the methacrylylphenyl ester of cetylhydroxybenzoic acid (C 16 ester) and cetyl methacrylate, relative to copolymer composition. It is shown that strong intramolecular interaction between the C 16 ester side groups leads to marked local kinetic rigidity of the copolymer molecules along with quite low equilibrium rigidity of the copolymers and homopolymers. The non-linearity of the reduced flow birefringence and Kerrs constant relative to copolymer composition was found by experiment. The experimental results are in good agreement with the theoretical dependence of segmental optical anisotropy on copolymer composition taking into account changes in the effective monomeric anisotropy of the component that is responsible for the intramolecular structure formation (C 16 ester).

The liquid-crystalline intramolecular order and the electron-optical properties of polyalkoxy benzoate molecules☆

Abstract The dependence of the equilibrium and non-equilibrium electron-optical properties (the Kerr effect) on molecular weight have been studied on the solutions of methacrylphenyl esters of cetyl- and nonylhydroxybenzoic acids. The experimental Kerr dispersions point to the existence of fairly large intramolecular areas which become oriented by an alternating electric field. The orientation time τ for these is fairly large (about 10 −4 −10 −5 sec) and is practically independent of the molecular weight of the polymer, which is due to the relatively large mobility of these areas. The experimentally observed increase in the Kerr equilibrium constants K with the molecular weight M (in the Gaussian range of M ) is the consequence of the existence of a mesomorphic intramolecular state of the branched polyester chains.

Intrinsic viscosity, diffusion and sedimentation of copolymers of crystal-like molecules☆

Abstract A study was made of the relation between molecular weights and hydrodynamic properties of statistical copolymers of cetyloxybenzoic acid (C-16) phenylmethacrylic ester with cetylmethacrylate (CMA) of different compositions. Evaluation of unperturbed macromolecular dimensions gives the same statistical segmental values for both copolymers (A = 60 A ) and proves an increased equilibrium rigidity of main chains, compared with conventional flexible chain polymers, which is due to the presence of long lateral interacting groups. It was shown that the difference in the hydrodynamic behaviour of molecules of these copolymers in CCl 4 is due to the different thermodynamic properties of solvent for the constituting homopolymers.