Influence of Alkali Treatment on Physicochemical, Thermal and Mechanical Properties of Hibiscus Vitifolius Fibers

Abstract

ABSTRACT Hibiscus vitifolius was found to possess the promising potential required for reinforcing polymer matrices. In this study, Hibiscus vitifolius fibers were immersed in 2, 3, 4, 5, 6, 7, and 8% NaOH solution for 1 hr and the effects of alkali treatment on chemical, mechanical and thermal characteristics of the fiber were evaluated through chemical tests, X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis, tensile tests, and field emission scanning electron microscopy. From the test results, it was inferred that Hibiscus vitifolius fibers treated using 5% NaOH exhibited high crystallinity, tensile strength, and Young’s modulus compared to raw fibers. Beyond 5% NaOH treatment, the fibers suffered a decline in crystallinity index and mechanical properties. The morphological analysis of alkali-treated fibers revealed the removal of amorphous constituents and separation of fiber bundles into individual fiber filaments.