Development of multifunctional knitted fabrics and investigation of the durability of lignin-based textile coatings

This thesis focuses on the development of multifunctional knitted fabrics through the investigation of the durability of lignin-based textile coatings. Increasing environmental concerns and sustainability goals in the textile industry necessitate the replacement of fossil fuel–derived chemicals with natural, non-toxic coating agents. In parallel, growing consumer awareness and tightening international regulations have compelled manufacturers to seek eco-friendly alternatives. Recent studies have demonstrated that enhancing the durability of bio-based coatings on textile surfaces is critical for both product performance and human health. In this context, natural crosslinking agents such as sodium lignosulfonate and tannic acid were formulated into solutions at varying concentrations for application on knitted fabric surfaces. Prior to coating, the fabrics underwent standardized pretreatment processes to ensure effective penetration of the crosslinkers into the fabric surface. The prepared formulations were applied to cotton, cotton/polyester blend, and polyester knitted fabrics using the padding method. The durability of the applied coatings was evaluated in detail through spectrophotometric color difference measurements after pre-wash cycles in accordance with AATCC 135 standards, FTIR spectroscopy analyses, and modified flammability tests based on 16 CFR 1610 and ASTM D1230 standards. Experimental results revealed that sodium lignosulfonate and tannic acid achieved effective crosslinking within an optimal pH and formulation range. The findings indicated that coating performance varied depending on fabric type, solution concentration, and application parameters. Furthermore, the use of bio-based crosslinkers presents an innovative technological platform for the development of sustainable and durable functional textile coatings.