Crystallization from the glassy state

Abstract
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, Tg, was 1010 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 Tg 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.