Modification of polyolefins with silicone copolymers. II. Thermal, mechanical, and tribological behavior of pp and hdpe blended with silicone copolymers

Abstract

Thermoplastic polyolefin (TPO) films with permanent, silicone-rich, low-friction, low-abrasion surfaces were obtained by melt blending of high-density polyethylene (HDPE) and polypropylene (PP) with polydimethylsiloxane (PDMS)-containing block copolymers. Two different block copolymers, a siloxane-urea segmented copolymer and a polycaprolactone-b-PDMS triblock copolymer were used as modifiers at levels between 0.1 and 5.0% by weight. Blends were prepared in a twin-screw extruder. Modified films displayed surfaces with very low friction coefficients and high abrasion resistance, which depended on the type and the level of additive incorporated into the system. Bulk properties of these modified systems, such as crystallization and melting behavior or tensile properties, were not affected.