Polymerization of beta-Propiolactone in Wool

Abstract

The reaction of propiolactone with wool has been studied with the purpose of increasing the rate of reaction within the fiber, while still retaining the enhanced felting qualities of the modi fied wool. It was found that the presence of water in low concentration, added either to the wool or to the propiolactone in carbon tetrachloride, greatly accelerated this reaction. Excess water reduced the reaction, presumably because of lactone hydrolysis. Addition of water to the system also accelerated the reaction when ethyl, n-amyl, oleyl, or dodecyl alcohol was used as solvent, but not when methyl alcohol was thus employed. Significantly, the maximum rate of modification in a mixture of water and amyl, oleyl, or dodecyl alcohol was 30% greater than the maximum with water and carbon tetrachloride. Propiolactone reacts slowly with wool in methyl or ethyl alcohol in the absence of water, but with the higher alcohols, as with carbon tetrachloride, little or no reaction occurs unless water or methyl alcohol is present.

The influence of water and the lower alcohols in promoting interaction of propiolactone within the fiber appears to be the result primarily of swelling of the fiber structure to permit pene tration by the propiolactone. In the presence of water the higher alcohols, amyl and dodecyl, can penetrate to cause further swelling and increase in the rate of modification within the fiber.