Effect of Chemical Surface Modifications on the Properties of Alfa Fiber-Polyester Composites

Abstract

Composite materials based on Alfa fibers and unsaturated polyester resins were manufactured by the hand layup technique. Mechanical properties of composites prepared form Alfa fibers collected from the region of Boussaada (Algeria), treated by various concentrations of NaOH solutions (1, 3, 6, 9, and 12%) during 24 h were found to be better than those of the untreated ones. The 6% NaOH-treated fibers composite showed maximum improvement in tensile strengths about 63% and the 9% NaOH treated fibers composite showed maximum improvement in flexural strength about 52%, respectively. The tensile modulus improved by 50.48%. The flexural modulus was also improved by 44.06% compared to the untreated Alfa fiber composite. FTIR characterization of Alfa fibers showed that the number of hydroxyl groups (OH) decreased and the crystallinity index increase by 16.60% after alkaline treatment. SEM observations on fibers' surfaces showed that the alkaline treatment improved the interface adhesion of fiber–matrix.