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 Avrami's expression. It was found that n=2 (except at 145°C), and from Morgan and Keller's 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.