Investigation of long-term water absorption behavior of carbon fabric reinforced epoxy composites containing hydrophobic nanosilica

The effect of water absorption on the chemical and mechanical properties of hydrophobic filler containing epoxy matrix composites was investigated by keeping them in distilled water for 9 months. Aerosil R812 (8 nm) and Aerosil R972 (12 nm) were utilized at 3% and 5% w/w filler to resin ratio and the resin/filler mixture was combined with 12-ply carbon fabric to get 15 x 15 cm samples. Samples were molded under a hot press and for each sample 50 test samples obtained by cutting them with a water jet. The obtained samples were characterized by TG, FTIR, and SEM. The effect of water absorption was evaluated by measuring percentage water absorption and flexural strength of samples over 9 months. The results revealed that filler addition lowers the damage created by distilled water a considerable amount and addition of hydrophobic fillers to epoxy matrix composites can be especially beneficial for applications where long-term water exposure is desired.