Polymer Crystallization Process with Small Crystalline Aggregation

Abstract

The isothermal polymer crystallization near the glass transition temperature has been studied by wide-angle x-ray diffraction (WAXD), small-angle x-ray scattering (SAXS), and optical microscopy. The SAXS and WAXD results show the polymer crystallization proceeds with the nodular aggregation. The analysis of the SAXS results using Kolmogorov–Johnson–Mehl–Avrami theory indicates that the formation kinetics of the aggregation regions is of homogeneous nucleation type. The temperature dependences of the growth velocity and the nucleation rate of the aggregation region are a natural extrapolation of that of spherulite to the high supercooling region. This surprising results may require the construction of a new nucleation theory.