Effect of composition and processing conditions on the chemical and morphological evolution of PA-6/EPM/EPM-g-MA blends in a corotating twin-screw extruder

This study investigated the effect of blend composition and processing cond itions on the chemical conversion and morphological evolution of PA-6/EPM/E PM-g-MA blends along a twin-screw extruder. The maleic anhydride (MA) conte nt of the modified rubber was found to decrease strongly, to a level of alm ost zero, and in the melting zone the particle size was dramatically reduce d, from millimeters to submicrometers. Blend composition had a secondary ef fect on both chemical conversion and morphological development. The process ing conditions, particularly the temperature profile and the screw speed, a ffected both the chemical conversion and the morphological Evolution. Using low temperatures and low screw rotation it was possible to follow in detai l the evolution of morphological development of a reactive blend in a twin- screw extruder. (C) 2001 John Wiley & Sons, Inc.