Friction and Mechanical Properties of Highly Filled Polybenzoxazine Composites: Nanosilica Particle Size and Surface Treatment

Abstract

Frictional and mechanical properties of highly filled polybenzoxazine [poly(BA-a)] composites which are influenced by nanosilica contents, particle sizes, and surface treatments are investigated. The coefficient of friction and wear resistance, storage moduli, and microhardness of the nanosilica-filled poly(BA-a) composites systematically increase with an increase of nanosilica content, while those values of the nanocomposites are improved with decreasing particle sizes at the equivalent nanosilica content. The modulus can be predicted by the Kerner model with the maximum packing fraction, while the microhardness of the nanocomposites is in agreement with the Halpin–Tsai model. The nanocomposites fabricated with untreated nanosilica particles exhibit higher frictional and mechanical properties when compared with the surface-treated nanocomposites at the equivalent particle sizes. The interfacial interactions via covalent bond formation between the nanosilica and the poly(BA-a) are determinative factors for the nanocomposite properties. Highly filled nanosilica-poly(BA-a) composites can be employed in various applications where wear-resistance plays an important role. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim