Influence of water absorption track and pre‐drying treatment on the long‐term hydrothermal aging behavior of recycled jute fabric‐reinforced composites

Abstract Corrosion resistance and durability are always considered in the safety design of composite materials. In this study, recycled jute woven fabrics from coffee bags were used to fabricate jute/unsaturated polyester composites. The effect of water absorption and pre‐drying treatment on the long‐term hydrothermal aging behavior of the prepared composites, as well as the aging mechanism, was discussed. The hydrothermal aging test was performed at a fixed temperature of 80°C for specified conditioning times of 24, 120, 240, 480, and 720 h. Weight gain and weight loss values were recorded and compared. The mechanical properties were evaluated using a three‐point bending test and observations of the fracture area. The results showed similar water uptake and flexural behaviors between the composites with different pre‐drying treatments, especially after long‐term hydrothermal aging. It was also found that the moisture diffusion of the composite followed a Fickian process, and the flexural properties of the bending specimens at every position reduced with the aging time and initially decreased rapidly during the first 24 h of aging. In particular, the reduction rate in flexural properties generally followed the sequence of NO.1 > NO.2 > NO.6 > NO.5. Additionally, the aging mechanism study revealed three steps for the composites during the water absorption process. The inclusion of jute fiber as a composite material in this research provides insight into the water‐absorption mechanism of jute fabric‐reinforced polymer composite (JFRP). Highlights Recycled jute fabric‐reinforced composites were produced using jute fabrics obtained from recycled coffee bags. The effect of the water absorption track and pre‐drying treatment on the long‐term hydrothermal aging behavior of recycled jute fiber‐reinforced composite and its aging mechanism is discussed. The clarification of the aging mechanism indicates that there are three steps involved in the water absorption process. Considering jute fiber as a composite could help explain the water‐absorbing mechanism of JFRP.