Effect of non-ionic surfactant assisted modification of hexagonal boron nitride nanoplatelets on the mechanical and thermal properties of epoxy nanocomposites

Hexagonal boron nitride (hBN) nanoplatelets have attracted considerable interest recently. In this work, hBN nanoplatelets have been prepared using chemical exfoliation route. The exfoliation of hBN nanoplatelets takes place along the (0 0 2) plane without destroying the crystal structure. The hBN nanoplatelets are modified using polyvinylpyrrolidone (PVP), a non-ionic surfactant in order to achieve finer dispersion of hBN nanoplatelets in ethyl alcohol, and subsequently in the epoxy matrix. The enhanced dispersion of hBN nanoplatelets achieved using PVP is due to the adsorption of PVP over the hBN nanoplatelets, and PVP miscibility with epoxy resin in an uncured state. Due to the finer dispersion of hBN nanoplatelets in the epoxy matrix, the flexural properties are higher as compared to pure epoxy. PVP assisted dispersed hBN nanoplatelets reinforced with epoxy nanocomposites have higher flexural properties as compared to pure hBN nanoplatelets-reinforced epoxy nanocomposites. The enhanced dispersion of hBN nanoplatelets using PVA also limits the decrease in glass transition temperature (Tg). Further, thermal stability of the epoxy increase with an addition of PVP modified and unmodified hBN nanoplatelets in the epoxy matrix as compared to pure epoxy. Fractography studies reveal that addition of PVP modified and unmodified hBN nanoplatelets in the epoxy matrix depict rough surface with many small facets due to resistance offered by the dispersed nanoplatelets.