Effects of Thermal Cycling and Freezing after Water Absorption on Tensile Properties of Green Composites

摘要

The effects of thermal cycling and freezing after water absorption on tensile properties of green composites were examined. Jute fiber and matrix were used as the reinforcement and the matrix. The thermal fatigue was conducted as a fatigue test. Heating and freezing process are performed alternately for 0.5h, 1h and 24h during 10 cycles, heating and freezing temperature were 60°C and -20°C. In a freezing after water absorption, the damage by an expansion of water was examined. The freezing after the water absorption during 1-5 days was performed in a day under the environment of -20°C. In thermal cycling, tensile strength and modulus were significantly decreased as the time passes. In 24h-treated test, the decrease rates of tensile strength and modulus were about 50% compared with that of room temperature. In freezing after water absorption, tensile strength and modulus were decrease compared with that of the room temperature.