Controlling Degree of Polymerization of Cotton Linter for MakingIts Dissolving Pulp

摘要

Lyocell from wood dissolving pulp using environmentally benign solvent, NMMO, is used for making high quality fabrics, but is known to suffer from fibrillation phenomena upon repetitive physical damages, while the fabrics made from cotton linter dissolving pulp are not. To make cotton linter dissolving pulp using NMMO, its DP, crystallinity, alpha cellulose content, brightness, and metal ion content should be controlled. Electron beam irradiation, and acid treatment were used to reduce cotton linterDP and peroxide bleaching was followed for increasing brightness. The target DP was about 5-10 cps by CED (cupriethylene diamine] method. It was found that sulfuric acid treatment gave high brightness, high crystallinity and low alpha cellulose content while electron beam irradiation low brightness, and low crystallinity. It seems that by properly combining different methods on cotton linter treatment, its properties such as brightness, crystallinity and alpha cellulose content can be optimally controlled at the target DP.