The Cross–linking of Animal Fibres

Abstract

When animal fibres are treated with 3: 4–isopropylidene 1: 2 – 5: 6–. dianhydromannitol for 24: hr. at 50°c. in acid solution, cross–linking is brought about by reaction with the carboxyl groups of salt–linkages. The reaction proceeds more slowly at temperatures below 50°o., and degradation is severe at high temperatures because of attack on the disulphide bonds. Under optimum conditions at 50°c. the extent of cross–linking is small, giving only about 7% increase in the resistance of the fibres to extension in water at 22. 2°c, but even this limited amount of cross–linking causes an appreciable reduction in the milling shrinkage of flannel. AB the scaliness of the fibres is unaltered, the reduced shrinkage must be referred to the modified elastic properties of the fibres, in agreement with the results of experiments with other cross–linking agents.