Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Wool copolymers with low polymer content (6-18%) have been prepared by radiation grafting techniques. Supercontraction, density, and formic acid vapor sorption measurements have been used to assess changes in the keratin structure produced by the grafting processes. Kinetic studies of the contractile forces developed in the first (reversible) stage of the supercontraction of wool in lithium bromide showed that grafting with poly(N-methylol acrylamide) or polyacrylonitrile has a “repairing” action which offsets changes in the wool structure produced by the small radiation dose (2 Mrad) used for the grafting process. By contrast, grafting with poly(vinyl acetate) had no repairing effect. The bonds formed by grafting of poly(N-methylol acrylamide) or polyacrylonitrile to keratin do not reduce swelling of the wool by formic acid, which is a measure of effective crosslink density. Grafting with poly(vinyl acetate) led to increased swelling by formic acid, indicating some disruption of the keratin structure during polymerization. It is suggested that the role of the grafted polymer is mainly to stabilize the hydrogen-bonded secondary network by interaction between the polypeptide and polymer chains.
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