Effects of water absorption on mechanical properties of glass microballoons/vinyl ester syntactic foams

In this study, the water absorption of glass microballoon filled vinyl ester syntactic foams at room temperature (25°C) and high temperature (70°C) hygrothermal conditions was investigated. Water absorption rates varied due to the effect of density of syntactic foams because the pore and void containment attributed to higher glass microballoon content. The diffusion rate was varied when the syntactic foams were immersed in water with different conditions, such as salt water (SW) being slower than fresh water (FW) and double distil water (DD) due to the effect of pores. The mechanical properties of syntactic foams when immersed in different types of water at room temperature and under hygrothermal conditions for 30 days and 60 days also varied. It was found that both compressive and tensile modulus decreased when more microballoon content was added and when immersed for a long duration. This phenomenon was also attributed to pores and voids expanding their size compared to dry specimens. Hence, this was further evidence that porosity and void containment in the syntactic foams affected the mechanical and thermal properties.