Patent GB-1140690-A (GB)
Title: Copolymerization of unsaturated monomers with substrates
IPC: D06M14/06
Filed: 1966-02-04
Abstract: 1,140,690. Graft polymers. SCOTT PAPER CO. 4 Feb., 1966 [15 Feb., 1965 (6)], No. 5099/66. Heading C3G. An ethylenically unsaturated monomer is grafted, using a free radical initiator, on to a derivative of a substrate consisting of keratincontaining or amylaceous material or a waterinsoluble synthetic polymer containing reactive hydroxyl groups and/or ester or ether groups derived from reactive hydroxyl groups, said derivative being in the form of a half-ester and/or half-amide of di- or mono-thiocarbonic acid or salt thereof. Suitable monomers are substituted and unsubstituted hydrocarbons, including aromatic compounds; acrylic acids and derivatives thereof; vinyl esters, ketones and ethers; dicarboxylic acids and derivatives thereof and vinyl-substituted heterocyclic compounds. The substrate may be fibres, felts, threads and cloths of wool or mixtures of wool with nylon, polyester, polyacrylonitrile or polypropylene fibres; angora, cashmere, camel, alpaca, llama, vicuna, squirrel hair, hog hair or badger hair; potato, wheat, corn, rice or tapioca starch or esters, partial esters, ethers or hydroxy ethers of such starches; polyvinyl alcohol, partly saponified polyvinyl acetate, polyvinyl acetate, copolymers of vinyl acetate or vinyl alcohol, cellulose esters, partial esters and ethers in powder form or as fibres, non- woven sheets, threads or woven cloth. The substrates are treated with CS 2  or COS under alkaline conditions, e.g. with an alkali metal or alkaline earth metal hydroxide or basic salt, NH 4 OH or a quaternary ammonium, phosphonium, sulphonium, arsonium or stibonium hydroxide or with an organic amine, and the resulting solid derivative may be subjected to metathesis with a water-soluble salt prior to the graft polymerization, which may take place in bulk or in an aqueous solution, suspension or emulsion of the monomer. In Examples 1 to 37 and 47 wool is treated with NaOH, NH 4 OH, sodium silicate or aluminate, Na 2 S, Na 2 CO 3  or NaHCO 3  prior to reaction with COS or CS 2  and, in some cases, metathesis with a lead, aluminium, nickel, cobaltous, zinc or ferrous salt; the resulting derivative is graft polymerized with styrene and acrylonitrile, ethyl acrylate, acrylonitrile, acrylic acid or acrylamide. Mohair is treated in Examples 38 to 46 and 48 to 57 with sodium silicate or aluminate, Na 2 CO 3 , NaHCO 3 , methylamine, triethylamine or sodium stannate or cyanide prior to thiocarbonation, metathesis and graft polymerization with acrylonitrile, ethyl acrylate, acrylamide, acrylonitrile or styrene and acrylonitrile. In Examples 58 to 95 potato starch is thiocarbonated under alkaline conditions prior to metathesis and graft polymerization with the monomers used in the case of mohair and polyvinyl alcohol is similarly treated in Examples 96 to 119 and 123 to 143. Hydroxyethyl cellulose is treated in Examples 120 and 144 with NaOH and COS or CS 2  before graft polymerization with acrylonitrile and similarly in Examples 121 and 145 styrene and acrylonitrile, or acrylonitrile alone, are grafted on to thiocarbonated ethyl cellulose; and in Examples 122 and 146 acrylamide or acrylonitrile is grafted on to thiocarbonated cellulose acetate staple. Cyanoethylated cellulose fibre is treated in Example 147 with NaOH and COS before being grafted with acrylonitrile. In all the examples the graft polymerization takes place in an aqueous emulsion containing H 2 O 2 .