Fracture Toughness of Carbon Nanofiber Reinforced Polylactic Acid at Room and Elevated Temperatures

Abstract

Summary Polylactic acid (PLA) is a biodegradable plastic made from lactic acid, and can be produced by renewable raw materials. The mechanical properties of PLA are, however, not sufficient for structural materials. In our study,carbon nanofiber reinforced PLA was fabricated to overcome the deficiency of PLA and the mechanical properties were measured at room and elevated temperatures. Vapor grown carbon fiber (VGCF) was used for reinforcement. Three point bending specimens were fabricated by using injection molding, and then bending stiffness,bending strength and fracture toughness were measured for amorphous and crystallized specimens. As a result, it is shown that the bending stiffness increases with increasing the weight fraction of VGCF, but the addition of VGCF does not affect the bending strength and fracture toughness.