Masahiro Hatano

Crystallization of poly-[3,3-bis(chloromethyl)oxacyclobutane]

Abstract The crystallization phenomena of poly[3,3-bis-(chloromethyl)oxacyclobutane] have been investigated by the methods of X-ray diffraction, dilatometry and infra-red spectroscopy. The rates of crystallization to the α-form of the polymers, having various values of intrinsic viscosity, were measured dilatometrically at the constant crystallization temperature over the range 140°–160°C and the results indicated that a maximum value might exist at a temperature lower than 140°C, probably close to 130°C. The experimental results were used to obtain the k and n values in Avramis expression. It was found that n =2 (except at 145°C), and from Morgan and Kellers theory this would indicate that fibrillar growth follows nucleation which is sporadic in time. The fully extended specimen showed infra-red dichroism in the region 3000-500 cm −1 . As the crystallization of polymers proceeded, the absorption band at 897 cm −1 increased markedly in intensity, whereas the intensity of the absorption band at 1027 cm −1 decreased, suggesting that the former is a crystalline and the latter an amorphous band. The rates of crystallization deduced from plots of the optical densities of these bands against temperature, were in good agreement with those obtained dilatometrically.

Electrical Conduction of Poly-Acetylene under High Pressure

The thermal activation energy of the electrical conduction in the polyacetylene powder was measured as a function of pressure in the temperature range from room to liquid nitrogen temperature. The thermal activation energy of 0.27 eV at atmospheric pressure decreased to 0.17 eV at 100 kbar. Contrary to the expectation, the pre-exponential factor of the conductivity did not change at all. These results suggest that for this material the energy gap changes with pressure, while the probability of the carrier transfer between molecules does not change with the pressure.