Moisture barrier properties of glass fiber reinforced nanocomposites for marine applications

Glass fiber reinforced polymers are widely used for broad structural applications, as they are lightweight and have high specific strength. However, its underwater structural applications were not much explored owing to the concern related to its moisture absorption and degradation of its properties. In this work, attempts have been made to evaluate the moisture barrier properties of glass fiber reinforced plastic nanocomposites fabricated using hydrophobic nanosilica (20 nm) in different compositions (0.1 % to 5 %) for marine applications. An increased filler concentration exhibits a slight improvement in the thermal stability, concluded by the thermogravimetric analysis (TGA). Also, the morphological study using scanning electron microscopy (SEM) confirms the uniform distribution of the glass fibre throughout the matrix. Water vapour transmission rate (WVTR) showed that the moisture transmission is reduced for nanocomposites, except for the highly filled composite, owing to the agglomeration of silica particles with high filler concentration. Moisture barrier studies at room temperature and 80 °C and at different hydrostatic pressures (10 bar, 30 bar, and 60 bar) of glass fiber reinforced plastic nanocomposites followed typical Fickian behaviour of water absorption, and these studies revealed that the nanocomposite with 0.1 weight percentage of silica exhibited higher moisture barrier property.