Crystallization from the glassy state

Isothermal crystallization of poly[3,3‐bis(chloromethyl)oxacyclobutane] and poly‐(ethylene terephthalate) from the quenched glassy state gave small lamellae approximately 1000–2000 A. in lateral dimension with a constant thickness of about 100 A. The maximum primary nuclei density for crystallization slightly above the glass transition temperature, T g , was 10 10 greater than frequently observed during spherulitic growth from the melt. Since the lamellae grow at a linear rate, the crystallization process could be described by the Avrami theory for two‐dimensional growth with a constant nuclei density. By assuming that crystallization near T g is diffusion‐controlled, bulk crystallization rate data were analyzed to obtain self‐diffusion coefficients whose activation energies were similar to reported values for other polymers.