Abstract:
In this work silicon nitride (Si3N4) fibres were successfully functionalised with γ–glycidoxypropyl trimethoxysilane (GPS) coupling agent. The surface modification was used as a method to enhance the dispersion and adhesion of the fibres in epoxy polymer composites. It is well known that strong interfacial adhesion between dispersed inorganic fibres and a polymer matrix improves the mechanical properties of the composite by providing an effective stress-transfer pathway between the matrix and the fibres. The pre-functionalised fibres were dispersed into a commercial epoxy resin via tumble-mill mixing and ultrasonication and were cured, via addition of an amine hardener, at room temperature for 24 hours. The fractured surfaces of the cured composite materials were analysed via SEM imaging and the mechanical properties of the composites were tested. The GPS-Si3N4 composites were shown to have improved mechanical properties compared to the unfunctionalised Si3N4 composites, with improved tensile strengths and hardness values.