Influence of alkali treatment on physiochemical and morphological properties of palmyra fibers

As a part of sustainable development in construction, natural fibers are used as reinforcement in cement composites. The degradation of these natural fibers in matrix has led to growing interest among researchers to enhance the fiber properties by adopting suitable treatment techniques. This research focuses on examining the influence of alkali treatment on various aspects, including the physical, chemical, crystallinity, mechanical and surface characteristics of palmyra fibers. Herein, the palmyra fibers were immersed in alkaline solution for different duration (30 minutes, 60 minutes and 120 minutes) to arrive at optimum treatment period. The investigation utilizes XRD, FTIR, SEM and EDS analysis to gain insights into these properties. The findings indicated that the treatment effectively removed excess amorphous components like extractives, hemicellulose and lignin leading to the increase in crystallinity index and surface roughness. The crystallinity index increased by 11 %, 13 % and 23 % for 30 minutes, 60 minutes and 120 minutes treatment respectively. The water absorption of palmyra fibers reduced by 13 %, 14 % and 14 % for 30 minutes, 60 minutes and 120 minutes treatment duration respectively. Additionally, SEM-EDS exhibited best results for 60 min treatment of fibers, with 38 % increase in Oxygen to Carbon ratio of cellulose compared to untreated fibers. Among the different treatment duration, the 60 minutes treatment duration of fibers in 0.5 M sodium hydroxide solution has exhibited considerable enhancement in properties. These enhancements in palmyra fiber properties post-alkali treatment suggests their potential utility in the reinforcement of composites using alkali treated palmyra fibers.