Wide angle X-ray diffraction study of the solid-phase chlorinated poly(ethylene)

Abstract

Series of samples of solid-phase chlorinated poly(ethylene) (CPE) have been studied by using both the methods of wide angle X-ray diffraction analysis (WAXD) and optical microscopy. Some basic crystallographic characteristics of CPE of 1.27 to 56.09 chlorine content were determined. The increase of chlorine content in the product was found to result in a relatively weak increase of the parameter a for melt-crystallized samples, whereas the parameter c values of the cold-sintered samples decreased. The crystallite sizes in the [110] and [020] directions for the melt-crystallized samples increased to the higher extent up to, approximately, 10% chlorine content, as compared to those of CPE available as powder or pellets. The degree of crystallinity was reduced as the chlorine content increased, but, even with 56% chlorine introduced, the polymer had a crystalline-amorphous structure. The optical micrographs showed that, up to 40% Cl, CPE had crystalline structure dominated by the formation of spherolites whereas, at higher chlorine content, structures of the lower order of crystallinity were formed. These observed changes were predominantly determined by the defects in the PE crystals, resulting from the inclusion of a certain fraction of chloromethylene groups therein.