Degumming Gonometa postica cocoons using environmentally conscious methods

[摘要] English: The trend in the textile industry is at present towards eco-friendly processes and minimising the adverse ecological effects of production. Silk degumming is a high resource-consuming process, as far as water and energy are concerned. It further is ecologically questionable, because of the high environmental impact of effluents. The development of an effective degumming process would mean saving water and energy, recovery of valuable by-products such as sericin peptides, and lower environmental impact of effluents. The aim of this study was to develop and evaluate environmentally conscious degumming methods that could discriminate between sericin and fibroin, without harming the fibroin.The methods used and evaluated as environmentally conscious methods were tested against Orvus paste and all the samples were exposed to the method at a constant temperature of 32°C and a period of 10 days.Results indicated that an increased degumming time resulted in a decrease in the silk fibroin average molecular weight. A clear band at 25 kDa appeared with all the methods, indicating that the light chains were separated from the heavy chains during degumming.The degumming weight loss ranged from 27 to 41% over a time period of 10 days. Two of the methods namely the combination Orvus paste and Eucalyptus oil and catholyte were more efficient than Orvus paste. The SEM micrographs showed no fibrillations. This indicated further that the degumming methods were successful; the sericin was removed without damage done to the surfaces of the fibres.The maximum load and displacement means of the fibres differed with the different degumming methods applied. The strongest fibres were obtained from the control method. The weakest fibres came from the Vermicompost method.The results demonstrated that the environmentally conscious methods allow efficient, low cost degumming of sericin.

[发布机构] University of the Free State