Novel Ethylene/Alpha-Olefin Copolymer - Polypropylene Blends for Thermoforming, Blow Molding and Extruded Profiles

摘要

New ethylene/alpha-olefin copolymer elastomers are now available to manufacturers requiring thermoplastics polyolefin (TPO) compositions with enhanced melt strength. The melt strength characteristics and other associated physical properties of compositions produced from elastomer-rich/polypropylene (PP) blends are similar to previously introduced formulations of ethylene/1-octene and PP, which were reactively modified by peroxide during compounding. These simple blends exhibit the melt strength required for thermoforming, extrusion blow molding, and profile extrusion and offer the fabricator reduced sheet or parison sag, improved post die set up, and in some cases reduced gloss. The enhanced performance attributes are a feature made possible via patented reactor based technology for ethylene alpha olefins. Extruded sheeting and profiles can be produced from pre-compounded blends or via in-line blending of the high melt strength elastomers and PP using a single screw extruder with appropriate mixing, or twin screw extruder, allowing for removal of one heat history and processing step which reduces final part cost. The elastomers with higher levels of long chain branching are presented along with elastomer-rich blends using various PPs. Sheeting produced from simple blends compare favorably to sheeting produced from compounds that were produced via reactive extrusion and the blends are seeing success in extrusion blow molding and extruded profile applications.