Evaluation of Mechanical and Thermal Properties on a Composite Material of Bagasse Fiber and PLA

In this study, the mechanical and thermal properties of composite materials of bagasse fiber and bio-based polymer of poly (lactic acid) (PLA) were investigated. PLA and bagasse fiber, which is sugar cane residue after squeezing, were compounded into a composite resin and injection-molded to a specimen. The tensile test and the Izod impact test of a composite material of bagasse fiber and PLA were conducted. The tensile strength and the tensile modulus increased with increasing the content of bagasse fiber although the elongation at break slightly decreased. The Izod impact strength of bagasse fiber and PLA with plasticizer after the thermal treatment greatly increased. Micrograph observation showed the bagasse fiber which has a honeycomb structure in the cross section was compressed in the injection molding. The compressed bagasse fiber contributed to increase the tensile strength. It was also found that the tensile strength and the Izod impact strength of a composite material of bagasse fiber and PLA with the surface treatment increased for both before and after the thermal treatment at 70 degrees C. The PLA containing 20wt% of bagasse fiber had high heat resistance, but the PLA compound containing 20wt% of bagasse fiber and 10wt% of plasticizer had the higher heat resistance. The XRD, DSC, FT-IR analysis clarified the mechanism and roles of bagasse fiber and plasticizer in the crystallization process of PLA. It was found that the crystallization was accelerated due to lignin leached from bagasse fiber.