Effects of Fiber Content and Alkali Treatment on the Mechanical and Morphological Properties of Poly(lactic acid)/Poly(caprolactone) Blend Jute Fiber-Filled Biodegradable Composites

An attempt was made at increasing both toughness and rigidity by simultaneous toughening and reinforcement. Natural fiber-reinforced biodegradable polyester blend composites were prepared from modified and unmodified biodegradable polyesters blends with surface-treated and untreated jute fibers by melt mixing and subsequent molding. The resulting cross-linked and uncross-linked poly(lactic acid) (PLA)/poly(caprolactone) (PCL)blends were used as the biodegradable polyester matrixes. Alkali treatment was performed as the surface treatments on the jute fiber. This study revealed that alkali treatment of the jute fiber improved the mechanical properties of the composites. The addition of dicumyl peroxide (DCP) also imparted significant changes to the PLA/PCL blend as revealed by thermal and dynamic mechanical analyses. Morphological observation of the DCP modified blend revealed the existence of a third phase at the boundary region of the PLA and PCL phases that could be termed the 'interphase,' while extensive plastic deformation of the tensile fracture surface of the DCP modified blend was observed. The crystalline nature of PLA and PCL are retained in the blend, while the presence of jute fibers interferes with cold crystallization.