IMPACT MODIFICATION OF THERMOPLASTICS

摘要

A process to improve low temperature impact performance of a thermoplastic selected from the group consisting of thermoplastic polyurethanes, polyvinyl chlorides, styrenics, engineering thermoplastics, and polyolefins characterized in that the thermoplastic is compounded with at least one substantially linear ethylene/ alpha -olefin polymer, the polymer backbone of which is substituted with 0.01 to 3 long chain branches having a chain length of at least 6 carbons per 1000 carbons and which does not contain a polymer fraction with a degree of short chain branching less than or equal to 2 methyls/1000 carbons and does not contain a polymer fraction with a degree of short chain branching equal to or more than 30 methyls/1000 carbons, wherein the substantially linear ethylene/ alpha -olefin polymer is characterized as having: a) a melt flow ratio, I10/I2,≥5.63, b) a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≤(I10/I2) - 4.63, and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylene/ alpha -olefin polymer having about the same I2 and Mw/Mn.