GB876535A - Graft copolymers and shaped articles consisting of or containing them - Google Patents

Abstract

Graft copolymers comprising 98%-75% of a polymerized mono-olefin containing from 2-3 carbon atoms in the molecule and grafted thereon from 2%-25% by weight polymer chains of a monoethylenically unsaturated carboxylic acid, such as acrylic and/or methacrylic acid, are produced by creating active centres or sites, which are capable of initiating vinyl polymerization, along the chains of a polymer or copolymer of ethylene and/or propylene and reacting the activated polymer with the acid at 65 DEG -175 DEG C. The initial polymer may be polyethylene, polypropylene, a mixture thereof or an ethylenepropylene copolymer, and activation may be effected by treatment with high energy radiations such as gamma rays, X-rays or high-speed electrons, or by treating with ozone. The monomer is preferably reacted with the activated polymer in the presence of a diluent which may swell or dissolve the polyolefin, such as benzene, toluene, xylene, dioxan, hexane, heptane or octane. The carboxylic acid groups of the copolymer can be converted to salt groups such as the sodium, calcium, barium, magnesium or copper salt.ALSO:Graft copolymers comprising polymer chains of acrylic acid grafted on to polyethylene (see Group IV(a)) are compression moulded on to a brass sheet at 185 DEG -200 DEG C. under an applied pressure of 8000 p.s.i.g. to form a graft polymer film adhered to the sheet. The graft copolymers may also be similarly adhered to copper, magnesium, aluminium and steel sheets.