Eco-composite from poly(lactic acid) and bamboo fiber

Bamboo fiber-filled poly(lactic acid) (PLA) eco-composites were prepared by mechano-chemical compositing with bamboo fiber (BF)-esterified maleic anhydride (MA) (BF-e-MA) in the presence of dicumyl peroxide as a radical initiator. Tensile properties of the composites were improved by adding BF-e-MA and the dicumyl peroxide. A sufficient effect of the addition on the tensile property of the composites was observed even in the presence of the dicumyl peroxide of 0.25%. However, the composites with BF-e-MA usually showed a higher activation energy for thermal flow, indicating that their flow became more difficult, because molecular motions were rather suppressed by cross-linking of BF-e-MA with the PLA matrix resin. The crystallization temperature of PLA became higher by the addition of BF and BF-e-MA in non-isothermal crystallization. It was confirmed by scanning electron microscope and polarizing microscope observation that interfacial properties between BF and PLA were improved after the addition of BF-e-MA. A diffusion coefficient (D) of water in the PLA/BF composites with BF-e-MA was smaller than that in the composites without BF-e-MA. An equilibrium water-sorption amount (M∞) was higher in the order of composites without BF-e-MA>composites with BF-e-MA>pure PLA.