Effect of Surface Functionalization of Hemp Fiber on Mechanical Properties of Fiber and Composites with Poly Lactic Acid (PLA) Matrix

摘要

High crystalline natural fibers have various advantages for composite applications including low density, high specific strength and stiffness, high impact resistance, high acoustic absorption, reduced machine wear and biodegradability, compared to their synthetic counterparts. For instance, current research demonstrates that the strength of single hemp fiber can reach to 1.1 GPa with the corresponding elongation at break ranging from 1.3-4.7%. However, the major disadvantage of natural fiber composites is the incompatibility of the polar surface of fiber with hydrophobic nature of polymer leading to weak interfacial adhesion. This could be improved by chemical modification of fibers. In this study, we systematically investigated three chemical modification effects on hemp fiber surface morphology, surface chemistry, fiber strength and the bulk mechanical properties of composites synthesized with poly lactic acid matrix. The thermal stability of the resultant composites is also examined with the function of kinetic energy of fiber-matrix interface using thermal degradation methods.