Role of pretreatment with potassium permanganate and urea on mechanical and degradable properties of photocured coir (Cocos nucifera) fiber with 1,6‐hexanediol diacrylate

Coir fibers were modified with 1,6‐hexanediol diacrylate (HDDA) using ultraviolet (UV) radiation. Concentration of HDDA, soaking time, and radiation dose were optimized and found to be 30% HDDA in methanol along with photoinitiator Irgacure‐500 (2%) and 120 min of soaking time registered as the better performance (polymer loading (PL) 7%, tensile strength factor, Tf = 1.50). Urea of different concentrations (0.5–2%) were incorporated with 30% HDDA to monitor its effect on the properties and 1% urea produced the best results (PL = 25%, Tf = 1.82). For the improvement of the properties, the fibers were subjected to surface treatment with potassium permanganate (KMnO4) of different concentrations at various treating times. Enhanced properties (PL = 86%. Tf = 4.42) of the fibers treated with KMnO4 (0.05%) were obtained. The KMnO4 treated fibers were again treated with HDDA (30%) solution along with urea (1%) and found to produce the best results (PL = 100%, Tf = 4.5). Water uptake and degradable properties of the treated and virgin fibers were obtained.