Hydrolytic stability of PLA yarns during textile wet processing

PLA knitted fabric was subjected to various textile wet processes viz., scouring, bleaching, and simulated dyeing. Various process parameters viz., temperature, time, and pH of the chemical bath were studied to investigate their effect on the hydrolytic stability of PLA fibers. The hydrolytic stability was measured in terms of weight loss and mechanical properties of PLA yarns. Infrared spectroscopy was carried out to investigate the surface chemistry of greige and processed PLA fibers. SEM was employed to investigate the surface morphology of fibers. The results showed that scouring should be carried out around glass transition temperature (T _g ) of the PLA polymer. Bleaching with hydrogen peroxide proved to be very deleterious to the fiber structure. Simulated dyeing of PLA at higher temperature and longer process times severely degraded the mechanical properties of PLA yarns.