GB1482143A - High nitrile polymers - Google Patents

Abstract

1482143 Grafted butadiene-styrene rubbers; poly blends MONSANTO CO 8 Oct 1974 [9 Oct 1973 (2)] 43492/74 Heading C3G A graft polymer is produced by a process comprising (A) admixing (1)100 parts by weight of a rubbery polymer substrate having a butadiene content of 68 to 72% by weight and a styrene content of 28 to 32%, based on the total weight of butadiene-styrene rubbery substrate, which substrate has a refractive index of from 1À5375 to 1À5425, a particle size of from 0À06 to 0À2 micron, a gel content in the range from 40 to 95%, a swelling index of from 10 to 40 and a second order transition temperature (Tg) of less than - 20‹ C., (2) at least 10 parts of a first polymerizable monomer formulation comprising (a) from 0À1 to 2% of a non-conjugated diethylenically unsaturated monomer; (b) from 0 to 30% of acrylonitrile, alone or together with up to 20% methacrylonitrile; (c) from 40 to 60% of a vinylidene aromatic monomer; and (d) from 20 to 50% of a C 1 to C 8 -alkyl ester of acrylic or methacrylic acid, wherein the per cent by weight is based on the total weight of the monomer in the first polymerizable formulation; (B) subjecting the mixture to polymerization conditions to effect polymerization of said monomer formulation and grafting of the polymer produced on to the rubbery substrate; (C) admixing said graft polymer with a second polymerizable composition comprising from 55 to 85% of acrylonitrile or a mixture of acrylonitrile and methacrylonitrile containing up to 20% of methacrylonitrile and from 45 to 15% of a monovinylidene aromatic monomer, wherein the per cent is based on the total weight of the monomers in the second polymerizable monomer mixture; and (D) subjecting the second mentioned mixture to polymerization to produce grafting of the polymer being produced on to the said graft polymer to form a composite graft polymer, said first and second polymerizable compositions comprising at least 38% by weight ethylenically unsaturated nitrile monomer and 15 to 250 parts of monomer per 100 parts of rubbery substrate. Examples are given in which the butadiene-styrene rubber is grafted in aqueous media with (i) styrene, acrylonitrile, methyl methacrylate and ethylene glycol dimethacrylate, followed by acrylonitrile, styrene and, optionally, methacrylonitrile, the resulting graft polymer being blended with styrene acrylonitrile copolymer; (ii) styrene, acrylonitrile, methyl methacrylate and ethyleneglycol dimethacrylate, followed by styrene and acrylonitrile, the resulting graft polymer being blended with acrylonitrile-styrene-methyl methacrylate copolymer; (iii) styrene, acrylonitrile, methyl methacrylate and allyl methacrylate followed by styrene and acrylonitrile, the resulting graft polymer being blended as in (i) and (iv) styrene, acrylonitrile, methyl methacrylate and vinyl crotonate, followed by acrylonitrile and styrene, the resulting graft polymer being blended as in (i).