METHOD FOR VISBREAKING FLEXIBLE OLEFIN POLYMER COMPOSITIONS

摘要

A method for visbreaking a flexible polyolefin composition comprising: irradiating under a blanket of an inert gas a polyolefin composition comprising (A) about 8 to about 40% by weight of a crystalline polymer fraction selected from: (i) a propylene homopolymer; (ii) a copolymer of propylene; and (iii) a mixture of (i) and (ii); and (B) about 60 to about 92% by weight of at least one elastomeric copolymer; treating the irradiated polyolefin composition of step I with a peroxide in an amount from about 0.1 wt% to about 10.0 wt%, in a first gas mixture containing greater than 0.004% but less than 15% by volume of active oxygen; and extruding or compounding the treated polyolefin composition of step II in the molten state, thereby producing a visbroken polyolefin composition.