Nanoclay and Water Uptake Effects on Mechanical Properties of Unsaturated Polyester

Unsaturated polyester/nanoclay (UP/NC) composites were developed using an optimized process, which combines high shear mixing (HSM) and ultrasonication. Different types of organically modified nanoclays (Cloisites 10A and 20A and Nanomer I.30E) were considered with I.30E resulting in the best morphology with an exfoliated structure. This and the higher aspect ratio of I.30E lead to its better performance under tensile and flexural testing. Different loadings of I.30E (0, 1, 2, 3, and 4wt%) were thus used to manufacture UP/NC nanocomposites and test their resistance to water uptake as well as the moisture ingress effects on their mechanical properties. The results showed that the addition of I.30E nanoclay enhanced the hydrophobicity of the nanocomposite with a maximum improvement of about 40% at 4wt% of NC loading. Flexural test results revealed relative degradation in the flexural properties of neat UP and UP/NC, due to moisture uptake. However, the reduction in flexural properties was found to be minimal at the optimum nanoclay loading of 3wt%.