Physico-Mechanical Characteristics of Chemically Treated Novel Caesalpinia Pulcherrima Leaf Fibers as Potential Reinforcement for Polymer Composites

The present work aims to determine the suitability of natural cellulose fibers obtained from the secondary rachis of Caesalpinia pulcherrima as a sustainable fiber for polymer composites. Caesalpinia pulcherrima fibers investigated in the present study represent an unexplored natural fiber system compared with extensively studied fibers such as jute, sisal and flax. The fibers were modified by 10% NaOH treatment for varied periods (1, 2, 3, 4 h) to improve their interfacial interaction and eliminate amorphous regions. Their structural and chemical analyses were determined using FTIR, X-ray diffraction, Scanning electron microscopy, and tensile tests. The alkali treatment decreased the amount of non-cellulosic components, including hemicellulose and lignin, and led to an increase in cellulose content from 49.40% to 53.93%. In addition, the treatment also improved surface morphology, crystallinity, and tensile strength of fibers. Among different treatment durations, the 2 h treated fiber showed the most balanced improvement in overall properties. Therefore, alkali-treated Caesalpinia pulcherrima fibers may serve as promising reinforcement for sustainable composite production. Developing natural fibers as reinforcements for polymer composites promotes sustainable production and consumption, reduces the carbon footprint, and supports sustainable architecture through the utilization of renewable, lightweight, and environmentally sustainable composite materials.