SMALL-ANGLE X-RAY-SCATTERING FROM HIGH-DENSITY POLYETHYLENE - LAMELLAR THICKNESS DISTRIBUTIONS

Small-angle X-ray diffraction patterns were recorded for a number of h igh-density polyethylene samples and were successively analysed by a f it with the calculated patterns corresponding to certain theoretical m odels. The parameters determined by the above fits were as follows: lo ng-period, crystallinity, mean dimensions of the crystalline lamellae, amorphous thickness, crystallinity and lamellar dimension distributio ns. Regarding the latter, two mathematical functions were used for the fits, i.e. a symmetrical and an asymmetrical type, and for all of the samples examined the function was determined which gives the best res ults. Finally, a correlation is suggested between the polymer molecula r weight and lamellar dimension distributions. Copyright (C) 1996 Else vier Science Ltd.