Polystyrene-Newspaper Composites Part I. Degradation of Polymer during Processing

Abstract

Newsprint reinforced polystyrene was prepared, and the effect of process ing conditions on viscosity (in terms of torque) and molecular weight of polystyrene was studied. Polystyrene was melted in an intensive mixer. The influence of processing tem perature, time, and roller speed was evaluated. Subsequently, newsprint fiber was added to the polymer melt, and the effect of fiber concentration on viscosity and molecular weight of polystyrene was evaluated. A significant decrease in torque and molecular weight was observed when the processing time was longer than 40 minutes. The process ing temperature exhibited discernible effects on torque, specific energy, and degradation of polymer. Torque increased slightly as the roller speed increased from 10 to 20 rpm and then decreased thereafter. However, roller speed appeared to have little effect on polymer properties. Drastic changes in torque, specific energy and polymer degradation were observed with increase of fiber concentration.