Dissolving waste wool by combination of reduction-metallic salt methods

The goal of this study was to realize the reutilization of waste wool,improve the recovery rate of macromolecular keratin.NaHSO3/LiBr/SDS dissolution system was used to treat the waste wool and prepare a non-toxic,stable keratin solution with high dissolving rate and high molecular weight.Taking wool dissolution rate and large molecular weight keratin extraction rate as test indexes,the optimum process conditions were determined by varying the dosage of reagent,pH value,and reaction time and temperature.The results showed that the wool dissolution rate was up to 94% and keratin extraction rate was 50.2% when NaHSO3/LiBr/SDS concentrations were 0.5,0.1,0.02 mol/L,respectively,pH=12,reacting at 90 ℃ for 4 hours.Without addition of LiBr,the reduction system kept a high dissolution rate,but the extraction rate was lowered(from 50.2% to only 30%).IR spectroscopy analysis showed that α-helical conformation keratin was dominating in the extracted keratin from the dissolution system with addition of LiBr.This system can be used in the research and development of textile materials and new functional fibers.