Effect of Chemical Treatment on Rice Straw Fiber Surface and Properties of Straw/Polylactic Acid Composites

In this work, rice straw fibers were modified using NaOH, KBM-403, and tetraethyl orthosilicate (TEOS), and the changes in the surface groups of the straw fibers before and after the modification were analyzed by infrared testing. Straw/polylactic composite were prepared by hot pressing, and the effects of the modifiers used on the properties of these blends were studied by conducting mechanical and thermal performance tests. The results showed that the tensile strength of the straw fiber composites modified by NaOH and KBM-403 increased by 20% and 21.2%, respectively, compared with that of the unmodified composite, whereas the tensile strength of the TEOS-modified fiber did not increase significantly. The flexural strengths of the composites increased by 10.2%, 11.1%, and 13.2%. The impact strength increased by 38.5%, 7.6%, and 7.6%. The results of thermal analysis show that initial and maximum thermal decomposition temperatures of the composite materials increased, indicating that the modified composite materials had a higher thermal stability. These blends are a kind of potential material for structural applications such as interiors, drywell and partitions for furniture.