CRYSTALLINE FORMS IN NASCENT POLYETHYLENE

The crystalline structure of nascent polyethylene prepared by heteroge neous Ti-Mg catalyst has been studied. The reflection for the 001 plan es in the monoclinic lattice from WAXD is more intense when the sample was synthesized at lower temperature, but remains constant for the sa mples at different polymerization yields. By treating the polyethylene powder by supersonic wave, a portion of the powder fell apart into sm aller particles. Among the particles, a single crystal in monoclinic f orm was found by using TEM and electron diffraction, The generation of the monoclinic crystal is considered to be the presence of compressiv e force in the polymerization process,which may arise from the crowdin g of the growing polymer globules.