Evaluation of Tensile Properties of Single Flax Yarn Reinforced Biocomposite Materials using Poly(lactic acid) and Shellac under Loading Speed

Recently, natural fiber is used as reinforcement such as building, bridge and architecture. And some companies are announced about unidirectional natural fiber tape for product of sustainable development of goals. But strain rate dependence of biocomposite material using natural fiber yarn should be considered for safety of structure. In this study, effect of loading speed on tensile property of biocomposite material using single natural yarn was investigated for new products. Matrices were poly(lactic acid) and shellac resins. Tensile tests of biocomposite materials were conducted under constant room temperature and humility room. The crosshead speed was 10-100 mm/min. The environmental temperature was 20 °C. The humility was 65 %RH. The following result was obtained. Tensile strengths of all biocomposite materials increased with an increase of loading speed. Tensile properties of all biocomposite materials at 100 mm/min was higher those of all biocomposite materials. But the large fiber-pullout on the fracture surface of biocomposite material using shellac resins was noticeably found after tensile test at 100 mm/min. Their results implied that tensile property of biocomposite material was affected by adhesion and tensile properties of matrices under loading speed.