Graft Copolymerization of 2-Hydroxyethyl Methacrylate (HEMA) on Persian Silk Yarn

Abstract

Silk is a highly valued animal fibre that has long been used to produce textiles of the finest quality. During the degumming process it losses almost 30% of its weight. The weighting of silk fibres with mineral compounds is an effective technique to counteract this loss in weight. Chemical modification by graft copolymerization of vinyl monomers is also effective.

Persian silk yarn was degummed using Marseille solution soap and graft copolymerized with 2-hydroxyethyl methacrylate (HEMA) in aqueous media by a redox initiator system. The percentage of HEMA in the feed varied from 0-100%. The grafting efficiency obtained was 70-90%.

The pH of the medium varied and its effect on the graft copolymerization was investigated. The grafted silk yarn gained in weight as the pH of the copolymerization medium was reduced and the time of copolymerization increased. Grafting affects the mechanical properties of yarn by reducing the tensile strength and slightly increasing the elongation of the yarn. The solubility in alkali solution improves as the yarn gains in weight. The infrared absorption (FTIR) spectra of the pure silk sample showed strong bands at 1540, 1635, and 1230 Cm^‒1, which are assigned to amid of I, II, III, respectively; and at 3417 Cm^‒1, which is assigned to OH. In the grafted samples, these peaks shifted to a higher wave number. The SEM studies were carried out to investigate structural properties of Persian silk yarn.

Citation

Salehi, A.H., Bahrami, S.H. and Arami, M. (2005), "Graft Copolymerization of 2-Hydroxyethyl Methacrylate (HEMA) on Persian Silk Yarn", Research Journal of Textile and Apparel, Vol. 9 No. 3, pp. 1-11. https://doi.org/10.1108/RJTA-09-03-2005-B001