A study on mechanical, structural, morphological, and thermal properties of raw and alkali treatedCordia dichotoma-polyestercomposite

Currently, natural fibers used as reinforcement with polymer composite materials is trending among many researchers, due to their significant properties like low density, light weight and biodegradability. One of such fibers isCordia dichotoma, which are cheap and available in abundance. TheCordia dichotomaffibers were extracted from its bark using water-retting process. These unidirectional fibers were reinforced in a polyester matrix, and mechanical properties such as tensile and flexural properties of the resulting composite were determined experimentally. TheCordia dichotomafibers were alkali treated with 5% NaOH solution to enhance bonding with matrix and the effect of this treatment on properties of the composite were explored. It was observed that 5% NaOH treatment gives considerable improvement in mechanical properties of the composite. FTIR spectroscopy was used to identify the functional groups and chemical compositions of the raw and alkali treated fiber composites. SEM analysis was carried out and resulting images revealed the existence of impurities on the surface of the raw fiber in the composite. Removal of the impurities with alkali treatment of fibers made the surface of the fibers rough and lead to improving the mechanical properties. Further, thermal stability (degradation temperature and weight loss) of raw and alkali treated fiber reinforced composites was studied using TGA.