An elastomeric composition and method incorporating a hydrocarbon polymer modifier with improved permanence. The composition comprises elastomer, filler and silane-functionalized hydrocarbon polymer modifier (Si-HPM) made in a pre-reaction adapted to couple the Si-HPM to the elastomer, filler or both, wherein the Si-HPM comprises an interpolymer of monomers chosen from piperylenes, cyclic pentadienes, aromatics, limonenes, pinenes, amylenes, and combinations thereof.

A composition comprising a mixture of: (i) an aromatic polycarbonate; (ii) a graft copolymer including polyacrylonitrile; and, (iii) a non-crosslinked acrylic polymer having a weight average molecular weight (Mw) of less than or equal to 65,000 Daltons (Da).

Disclosed are biaxially stretched polyolefin films containing 10 to 45% by weight of a cycloolefin polymer with a glass transition temperature between 12 and 170 C., and 90 to 55% by weight of a semi-crystalline alpha-olefin polymer with a crystallite melting temperature between 15 and 170 C. The glass transition temperature of the cycloolefin polymer is less than or equal to the crystallite melting temperature of the alpha-olefin polymer, and the polyolefin film has a shrinkage at 130 C. after 5 minutes, as measured according to ISO 11501, of less than or equal to 2%. These polyolefin films are excellently suited as dielectrics for capacitors and are distinguished by a low shrinkage at high temperatures. The cycloolefin polymer preferably forms a co-continuous phase in a matrix of the semi-crystalline alpha-olefin polymer, providing improved mechanical and electrical properties including a dielectric strength from 500 to 750 V/m.

A composition comprising a mixture of: (i) an aromatic polycarbonate; (ii) a graft copolymer including polyacrylonitrile; and, (iii) a non-crosslinked acrylic polymer having a weight average molecular weight (Mw) of less than or equal to 65,000 Daltons (Da).