CHANGES IN ROW STRUCTURE OF EXTRUDED POLYETHYLENE FILM ON GRAFTING WITH STYRENE - 1. DISTRIBUTION OF POLYSTYRENE AND CRYSTALLINE REORIENTATION.

In the reported experiments, extruded films of linear polyethylene were grafted with styrene in a 1:2 styrene-methanol solution and pure styrene. The reaction was induced by simultaneous gamma irradiation. Crystallinity of polyethylene was hardly affected by a polystyrene-to-polyethylene ratio as high as 13. 5. From the anisotropy of film growth and small-angle x-ray diffraction it was concluded that polystyrene incoporated both into intercrystalline layers and newly formed domains alongside the stacks of lamellae. The proportion of polystyrene in interlamellar layers depends on the length of grafted chains; that is, on grafting conditions. A higher than expected proportion of occluded homopolystyrene was found in films grafted in methanol solution. The glass transition temperature of polystyrene decreased with grafting yield. This was ascribed to untwisting and straightening crystalline lamellae in the row nucleated cylindrites.