| 摘要 |
<p>Graft copolymers are prepared in which the base polymer is a linear nitrogenous condensation polymer and the grafted units are linear chains free from aliphatic unsaturation which carry amide groups and are linked to the condensation polymer by carbon-carbon bonds. Condensation polymers specified are polyamides, e.g. polyhexamethylene adipamide and polycaproamide, polyurethanes, polyureas, poly(ether-urethanes) and polysulphonamides. The grafted side chains are produced by the polymerization of unsaturated amides in the presence of the condensation polymer, suitable amides being acrylamide, methacrylamide, ethacrylamide, N-methylol acrylamide, N-methyl-N-vinyl formamide, N-vinylpyrrolidone, N-vinyl-valerolactam and N-vinylcaprolactam. Mixtures of such amides with one another or with other monomers may be used. The grafting is preferably applied to the condensation polymer in shaped form, e.g. fibre or film, although other forms, e.g. flake, powder or melt, may be employed. The amide monomer may be used as such or in the form of an aqueous solution, polymerization being induced thermally, by the use of free-radical catalysts or by the use of ultra-violet light in conjunction with a photo-initiator, if desired. The process is used to confer desirable properties on the condensation polymer substrates; in particular, fabrics made from grafted nylon exhibit dyeability and may be subjected to a hydrosetting treatment whereby a permanent configuration is achieved. The Specification describes also the preparation of a poly(ether-urethane) by reacting poly(tetramethylene oxide) glycol with 4-methyl-m-phenylene diisocyanate to produce a dimer with hydroxyl ends, which is added to methylene bis(4-phenyl-isocyanate) dissolved in methylene chloride. To the isocyanate terminated dimer so formed are added dimethyl formamide and hydrazine hydrate and polymer is precipitated from the resulting solution by adding it to glycerol. Specifications 461,236, 535,139, 724,759, 838,412, 868,651 and 901,039 are referred to.</p> |
