Tussah Silk Fabric Research Articles

Chemical modification of tussah silk fabrics with ethyleneglycol diglycidyl ether by a pad‐batch method

Tussah silk fabrics have been chemically modified by pad‐batch treatment with ethyleneglycol diglycidyl ether (EDGE). The maximum amount of weight gain attained was 5–6%. Epoxide adducts were formed with tyrosine and basic amino acid residues. The moisture regain of the fabric with 3% weight gain decreased slightly compared with that of the untreated sample. The crease recovery in the wet state improved significantly, while in dry state it remained unchanged. Mechanical and optical properties, and X‐ray crystallinity did not exhibit noticeable changes. The position of the major DSC endothermic transition at 358d̀C remained unchanged, regardless of the epoxide modification. Similar comments apply to the TMA contraction peak occurring at about 359d̀C. The storage and loss modulus curves of EDGE‐treated tussah silk fibres exhibited some changes, the most relevant consisting in a shift to higher temperature of the loss modulus peak.

Silk finishing with epoxides

The pad‐dry‐steam and pad‐dry‐bake finishing of tussah silk fabric with triglycidyl ether of glycerol in the presence of catalysts has been investigated. Potassium thiocyanate was found to be the most effective accelerating agent for this purpose. The optimum treatment conditions for either steaming or baking are discussed. The reaction mechanism involving the formation of an epithioxide intermediate is proposed and was confirmed by determination of the sulphur content of the fabric. The processes described could be readily adapted for commercial exploitation.