EPITAXIAL-GROWTH OF ISOTACTIC POLYPROPYLENE ON ORIENTED POLYETHYLENE FROM SOLUTION

Oriented polyethylene (PE) films with surfaces bounded by the (100) plane were prepared. On the film surfaces, isotactic polypropylene (iPP) was crystallized epitaxially from solution as quadrites with their sides parallel and perpendicular to the polyethylene chain axis. In the through wide-angle x-ray diffraction pattern (taken with incident x-rays normal to the polyethylene film surface), the 111 iPP reflection was observed on the meridian (parallel to the polyethylene chain axis). In the edge pattern (taken with x-rays incident on the edge of the polyethylene film), 040 and 060 reflections were observed on the equator. From the diffraction patterns, the following lattice coincidence was observed between polyethylene and isotactic polypropylene: (010)iPP//(100)PE, [101]iPP//[001]PE. The small-angle x-ray scattering patterns showed that edge-on isotactic polypropylene lamellae 9 nm thick were arranged with their long axes inclined at an angle of 40-degrees from the polyethylene axis. Molecular chains were oriented within the lamellae normal to the surfaces.