Influence of Alkali Treatment on Mechanical Properties of Poly Lactic Acid Bamboo Fiber Green Composites

Abstract

In recent years, in order to reduce the environmental burden of composite materials, research has been conducted to develop composites made from plant-derived polymers and natural fibers, the so called green composites. In this study, green composites were made from polylactic acid (PLA), a bioplastic derived from corn starch, reinforced with bamboo fibers. The composites were manufactured by mixing short bamboo fibers and dispersion-type PLA resin. Subsequently, PLA/bamboo fiber sheets were molded by a hot pressing method. In order to improve the adhesion at the matrix/fiber interface and to obtain uniformly dispersed bamboo fibers in PLA matrix, the bamboo fibers were treated by alkali solution. It was found that the composites reinforced by alkali-treated bamboo fibers have higher strength than those based on untreated ones. Bamboo fibers were uniformly dispersed in PLA matrix with improved interfacial adhesion as lignin in bamboo fibers were removed by the alkali treatment. It was concluded that alkali treatment was an effective method for improvement of interfacial matrix/fiber adhesion in PLA/bamboo fiber-reinforced green composites.