As well known, sustainability issues represented by the environment and resource protection have been paid close attention nowadays. Natural fiber has been an increasing interest and promising as reinforcing fiber in polymeric composites due to its low density, cost, acceptable specific strength and biodegradation. Even though, the principle challenge for natural fibers used as reinforcement is their internal strong water-absorption ability when the exposed in wet and water environment.
Long-term hydrothermal degradation behavior of Glass reinforced composite (GFRP) and jute reinforced composite (JFRP) have been discussed in previous study on the basis of the great amount of physical and mechanical testing results. As former working reported, gained water content increases linearly against the square root of aging time followed by gradual increase trend in longer duration both in JFRP and GFRP. In particularly, JFRP’s weight loss performance occurred earlier with higher value compared to GFRP. However, water absorption and weight loss mechanism, relationship between weight change and retention of mechanical property for JFRP didn’t report and illustrate clearly and extensively. Therefore, in order to figure it out comprehensively, the current study was focus on hydrothermal ageing mechanism and corresponding degraded mechanical behavior.
Firstly, 2 layers of deeply dried and natural dried jute woven fabric reinforced unsaturated polyester were fabricated by hand-layup method. The cut samples were immersed into 80°C hot water bath for predetermined durations and inspected by ultrasonic wave. Afterwards, 3-point bending test with acoustic emission (AE) measurement was carried out for aged samples. The weight change mechanism, evolution of internal deterioration and mechanical property along with ageing time was investigated. The result indicated that JFRP can absorb water easily and quickly compared with GFRP owing to jute fiber’s hydroscopic nature. Weight loss was caused as a result of resin particle loss and pectin dissolution from the developed micro-crack owing to hydrothermal water environment. What’s more, internal serious deterioration occurred after 24 hours immersion leading to larger reduction of mechanical property.
