INVESTIGATIONS IN FIELD RADIATION-INDUCED SOLID-STATE POLYMERIZATION .24. POLYMERIZATION OF CETYL VINYL ETHER

According to our investigations, cetyl vinyl ether has a smectic liquid crystalline state between its m.p. (16·5°) and -2·5°. Below this temperature range, it has two different solid crystalline states with a phase transition point at -16°. Solid-state polymerizations carried out in the latter two systems gave kinetic curves with linear character but those curves obtained in the liquid crystal line phase were accelerating types. This observation can be explained by the formed polymer not destroying the crystal lattice but actually stabilizing the regular smectic structure. The transition from the liquid crystalline into the three-dimensional structure takes a few hours, therefore it is possible to carry out even below -2·5° an accellerating type of polymerization corresponding to the liquid crystalline structure. The mechanism of the polymerization is probably cationic. The polymers obtained show an optical birefringence and melt sharply at 36°. The structure of the polymer reflects that of the monomer matrix. This feature disappears only after having melted the system. The DP of the polymers does not depend on the polymerization parameters (temperature, dose rate), but is governed by the size of those crystal sections" which are perfect from the viewpoint of polymerization linkage. © 1969."