Mechanical and thermal properties of waste water bamboo husk fiber reinforced epoxy composites

Water bamboo husk is one of the major agricultural wastes in Taiwan. The carbon, oxygen and hydrogen contents of fibers obtained from the outer layer of water bamboo are 40.35, 46.20 and 6.60%, respectively. In this study, the fibers obtained from water bamboo husks were chemically modified by coupling agents. Moreover, the powders obtained from water bamboo husks were also used, but without chemical modification. Furthermore, the modified fibers and untreated powders were, respectively, added to epoxy resin to form novel reinforced composites. Morphologies, mechanical properties and heat resistance of these water bamboo husk reinforced composites were investigated. The results indicate that the fiber is cellulose I type. The morphology analysis reveals that the fibers modified by coupling agents exhibited better compatibility with the polymer matrices than the untreated fibers did. Moreover, the thermal resistance was improved as the plant fibers and powders were individually incorporated to those polymers. The increments of char yields of epoxy were about 13.5–52.8% with the addition of 10% fiber or powder. It is also found that the glass transition temperature of epoxy was increased to be about 8–18 °C higher than that of the pristine sample. In addition, the mechanical properties were also enhanced due to the addition of coupling agent treated fibers and untreated powders. The increments of storage moduli of epoxy were about 16.4 and 36.1% with the addition of 10% coupling agent treated fibers and untreated powders, respectively.