Effect of fiber surface-treatments on the properties of laminated biocomposites from poly(lactic acid) (PLA) and kenaf fibers

Kenaf fiber reinforced polylactic acid (PLA) laminated composites were prepared by compression molding using the film-stacking method. The objective of this study was to evaluate the mechanical and thermal properties of these composites as a function of modification of kenaf fiber by using alkalization and silane-treatments. It was found that both silane-treated fiber (FIBSI) reinforced composite and alkali treated fiber (FIBNA) reinforced composite offered superior mechanical properties compared to untreated fiber (FIB) reinforced composite. The alkali- followed by silane-treated fiber (FIBNASI) reinforced composite also significantly improved mechanical properties. The effects of temperature on the viscoelastic properties of composites were studied by dynamic mechanical analysis (DMA). The heat deflection temperature (HDT) of the PLA laminated composites is significantly higher than that of neat PLA resin. Moreover, morphological studies by scanning electron microscopy (SEM) demonstrated that better adhesion between the fiber and the matrix was achieved. It was found that standard PLA resins are suitable for the manufacture of kenaf fiber reinforced laminated biocomposites with useful engineering properties.