HIGH IMPACT STRENGTH POLYPROPYLENE PRODUCED VIA REACTIVE EXTRUSION WITH AN ETHYLENE-OCTENE COPOLYMER

摘要

Isotactic polypropylene (PP) has been reactively blended with an ethylene-octene copolymer (EOC) in a twin screw extruder. Without reaction, simple binary blends exhibit mechanical properties similar to what previous research has shown. Free radical polymerization of styrene and a difunctional acrylate during melt extrusion has resulted in an enhancement of mechanical properties and discovery of unique features in both amorphous and crystalline phases. SEM shows that by grafting onto the polymers, particle size and interparticle distance decrease, while particle shape becomes less spherical. Impact strength and stress-strain properties are enhanced by graft reactions. Melt flow index (MFI) is significantly decreased by the reactive extrusion process.