Biologically Degummed and Chemically Treated Okra Bast Fibers-Reinforced Poly(Vinyl Alcohol) Composites

This paper focuses on preparation of poly(vinyl alcohol) (PVA)-based composites reinforced with okra bast fibers at different percentages of 5, 10, 20% via solution casting method. Fibers obtained from different sections of okra plants were biologically degummed and scoured with Na2CO3. Selected fibers were bleached, treated with maleic anhydride or grafted with vinyl acetate. Mechanical, physical and biodegradational properties of the composites were investigated. The tensile strength of the produced composites ranges between 33.8 and 55.1 MPa, elasticity modulus from 1.8 to 2.6 GPa, elongation rate at break varies in 2.8-10%. Chemical treatments led to improved mechanical performance whereas increased fiber content reduces tensile strength, stiffness and elongation, as well as water absorption. Fiber addition significantly affected biodegradation in a complicated way: by decelerating mass loss but accelerating deterioration of mechanical properties.