Physical and mechanical properties of bamboo fibre/polyester composites subjected to moisture and hygrothermal conditions

Abstract

The widespread use of natural fibre reinforced composites is hindered by a few issues, some related to the durability of the natural fibre itself especially when exposed to certain environmental conditions. In this study, the moisture impact on the physical and mechanical behaviours of bamboo fibre/polyester composites was investigated. Composites fabricated using bamboo fibres and polyester resin were immersed in water at room temperature (25 ℃) for 60 days and at 80 ℃ for 2 days. The percentage of thickness swelling and surface expansion was recorded throughout the duration of the study, until apparent physical degradation was observed on the samples. At both temperatures, untreated and treated composites had similar swelling behaviour, with 8% NaOH-treated composite showing highest swelling rate. The surface area expansion for all composites was observed to be much lower than in the thickness direction and was relatively negligible. Since the percentage of final swelling was about the same for all composites, it was also found that the composites achieved similar maximum tensile strength for both conditions, with approximately 2% increment at room temperature and 13.6% reduction at 80 ℃.