In-Situ Polymerization of Maleic Acid in Presence of Aloe vera Gel for Development of Eco-Friendly Eri Silk based Handlooms

Polycarboxylic acid compounds such as butane-tetra-carboxylic acid, cyclopentane-tetra-carboxylic acid, and citric acid offer an environmentally friendly, non-toxic, and safe alternative to toxic formaldehyde condensate resin as a silk cross-linking agent. However, the sodium salts of phosphorus-containing mineral acids used as esterification catalysts with such polycarboxylic acids are not environmentally friendly because of their reported adverse effects on the aquatic environment and soil. Also, finishes based on such non-polymeric polycarboxylic acids cannot retain or improve the strength and moisture-regain characteristics of silk. Moreover, most polycarboxylic acids are too expensive for practical exploitation. In view of the above, the present work was aimed at establishing the optimum condition for the application of vinyl monomer containing carboxylic acid like maleic acid in presence of initiator and catalysts on silk fabric in the presence of ammonium persulphate as the free radical polymerization catalyst and trisodium citrate as the esterification catalyst. In this study, eri silk-based handloom fabrics were finished with Aloe vera gel and maleic acid as a cross-linking agent using the pad-dry-cure method. Water-soluble Aloe vera gel with varying concentrations of 5 to 15% (w/v) was also added in the finishing bath to add antibacterial activity to the fabric along with the anti-crease properties. Evaluation of attainable changes or improvements in the eri silk based handloom fabric properties in respect of tensile strength, wrinkle recovery, flexibility, antimicrobial, porosity and moisture regain on such treatments have been done. Besides this, changes in the chemical nature of silk fabric on such modifications have been studied by infrared (IR) spectroscopy and reported in this research article. The study proposes thermal curing system is conducive for in-situ polymerization of maleic acid in presence of Aloe vera for the development of eco-friendly eri silk based handlooms with antibacterial and anti-crease properties, without a significant loss in strength properties. The effects of the antimicrobial agent were assessed even after the 10 wash cycle.