Characterization of novel natural cellulosic fibers from purple bauhinia for potential reinforcement in polymer composites

The aim of the present work was to extract novel natural cellulosic fibers from the leaves of purple bauhinia trees. To the best of our knowledge, this is the first time that, the morphological, physical, chemical, structural, mechanical, and thermal properties of purple bauhinia fibers (PBFs) have been investigated and characterized. The lateral surface of PBFs exhibited impurities, and cellulosic and non-cellulosic constituents, while, the transverse section appeared porous. The high cellulose (60.54%) and low hemicellulose (9.17%) contents of PBFs indicated the potential to exploit the fibers as a reinforcement material in polymer composites. Analysis of the functional groups present in the PBFs confirmed the cellulose and hemicellulose contents. The crystallinity index of the PBFs was found to be 54.98%, and the crystallites were ordered in nature. The optimal mechanical properties were found to be a tensile strength of 373.3 MPa, a tensile modulus of 5.31 GPa and an elongation at break of 6.9%. The maximum degradation temperature of the PBFs was 341 °C, and the thermal activation energy of the fibers was determined using three different approaches. The results showed that, these fibers have the potential to be used as a reinforcement material for the fabrication of polymer composites with better mechanical and thermal properties.