Preparation and Mechanical Properties of Cotton Stalk Bast Fibers Reinforced Polylactic Acid Biodegradable Composites

摘要

The cotton stalks bast fiber was a new kind of natural cellulose fiber, the fibers had the similar properties as the flax fibers. Polylactic acid (PLA) is a class of biodegradable matrix material. As the flax fibers can be reinforced materials and then compounded with PLA, cotton stalks bast fibers as reinforced materials and PLA as matrix were used to make a kind of green and biodegradable composite in the experiment. The composites were prepared by mixing, molding and cold forming. Orthogonal experiment table including length of the fibers, mass fraction of PLA, molding temperature and molding pressure was devised. Then the tensile strength, flexural strength and impact strength were tested and the analysis of range and variance was done. The optimal processing condition was obtained as follows: length of the fibers was 6mm, mass fraction of PLA was 75%, molding temperature was 175°C and molding pressure was 12MPa. The result showed that the cotton stalks bast fibers reinforced PLA biodegradable composites had good mechanical properties. Through this study waste cotton stalks basts were turned into useful resources and provided a kind of environmentally friendly composites.