Fabrication of Poly(lactic acid)/Silkworm Excrement Composite with Enhanced Crystallization, Toughness and Biodegradation Properties

This study investigated and analyzed the mechanical and thermal properties as well as biodegradability of bio-plastic Poly(lactic acid) (PLA) and PLA/silkworm excrement (PLA/SE) composites fabricated by injection molding. Differential scanning calorimetry (DSC) results demonstrated that SE enhanced the crystallization ability of PLA represented by the increased crystallinity. The tensile strength of PLA/SE composites did not enhance when adding SE due to SE particles became drawbacks while stretching as well as the lower tensile strength of SE than PLA. However, the impact strength of PLA/SE 10% was enhanced approximately 30.1%, comparing with neat-PLA. Biodegradation experiment showed that PLA/SE composites had faster and obvious disintegration in 7 weeks, especially PLA/SE 20% composite, which indicating SE enhanced the biodegradability of PLA. Additionally, neat-PLA and the PLA in PLA/SE composites can be fully biodegraded.