Structure Development during Crystallization of Homogeneous Copolymers of Ethene and 1-Octene: Time-Resolved Synchrotron X-ray and SALS Measurements

Crystallization kinetics in a homogeneous copolymer of ethene and 1-octene with appended long chain branches has been investigated in real time by means of time-resolved light scattering under H_v (cross-polarized) and V_v (parallel-polarized) optical alignments using a CCD camera system, simultaneous small angle-X-ray and wide angle X-ray measurements using synchrotron radiation and differential scanning calorimetry (DSC). The data show that in the case of crystallization at large supercooling, a significant fraction of the crystallinity develops after the spherulites have become volume filling. The fraction of crystallinity that develops after primary crystallization increases with crystallization temperature. This opens up a challenge to explore the extent to which this behavior is universal in other crystallizable ethylene copolymers as well.