Water absorption, tensile, flexural and impact properties of aged bamboo fibre/nano CaCO3-modified unsaturated polyester composites

Abstract

ABSTRACT This paper presents the investigation on the effects of nano CaCO3 on the durability of bamboo fibres/unsaturated polyester composites aged in distilled water up to 112 days. The nano CaCO3 contents in the unsaturated polyester matrix were 0, 1, 3 and 5 wt%, while the bamboo fibre content in the bamboo fibre/nano CaCO3-modified unsaturated polyester composites was fixed by 25 vol%. It was found that the equilibrium water uptake and diffusion rate decreased up to 16.2 and 15.6 %, respectively, by adding nano CaCO3 up to 3 wt%; however, at the content of 5 wt%, they were higher than those of the unfilled composites. For the unaged composites, the tensile and flexural strengths were improved by adding nano CaCO3 up to 1 and 3 wt%, respectively, whereas adding 5 wt% could not give positive effects. On the other hand, the increase of nano CaCO3 up to 5 wt% increased the elastic modulus almost linearly for both loadings. For the aged composites, adding 1-5 wt% nano CaCO3 reduced the degradation of composites both in tensile and flexural loadings, but the best enhancement was obtained at the content range of 1-3 wt%. Under impact loading, adding 1-5 wt% nano CaCO3 enhanced the impact strength of composites, regardless of the ageing condition.