Effects of nano CaCO3 on the water absorption, tensile and impact properties of unsaturated polyester composites

Abstract

In this work, the effects of nano CaCO3 (NCC) on the water absorption, the tensile and impact properties of the unaged and aged unsaturated polyester resin (UPR) have been investigated. The specimens were aged in distilled water at room temperature. It was found that the water uptake and the diffusion rate of the NCC/unsaturated polyester composites tended to increase with the increase of NCC content, by about 15 and 31%, respectively, at the NCC content of 5 wt% compared to neat UPR. For the unaged specimens, the tensile strength was enhanced by adding the NCC of 1 wt% and tended to decrease beyond this content. For the aged specimens, the tensile strength tended to decrease with the increase of NCC content. Nevertheless, the elastic modulus of the unaged and aged specimens tended to increase up to the NCC content of 3 wt% and then decrease at the content of 5 wt%. The elastic modulus of the aged specimens was higher than those of the aged specimens due to water-embrittlement. The impact strength of the unaged and aged specimens tended to increase up to the NCC content of 5 wt%. However, the impact strength of the aged specimens was lower than those of the unaged specimens. The results suggested that the addition of 1 wt% NCC could compromise the tensile and impact properties of UPR both in unaged and aged conditions.

Keywords

• nano caco3
• unsaturated polyester
• water absorption
• mechanical properties