abstract |
The addition of a polyolefin-acrylic graft copolymer to blends of polyolefin and core-shell polymers improves compatibility and allows core-shell polymers to be used as processing and performance modifiers polyolefins. Generally the compatibilizing additive is a graft copolymer of a polyolefin and a metharcylate. More specifically, the graft copolymer is derived from at least about 80% of a monomer of a methacrylic ester of the formula CH 2 ═C(CH 3 )COOR, where R may be alkyl, aryl, or aralkyl, substituted or unsubstituted, and less than 20%, based on a total monomer weight, of an acrylic or styrenic monomer copolymerizable with the methacrylic ester grafted on to a non-polar polyolefin trunk, so that at least one chain is a polymer with a weight average molecular weight greater than about 20,000 and is present in a weight ratio with the polyolefin trunk of from about 1:9 to about 4:1. n A typical composition may contain about 20% core-shell modifier, about 10% compatibilizer, the balance being polyolefin. |