Novel glass fibre reinforced hierarchical composites with improved interfacial, mechanical and dynamic mechanical properties developed using cellulose microcrystals

Abstract

This paper reports the use of cellulose microcrystals (CMCs) for improving fibre-matrix interface, mechanical, dynamic mechanical and thermal degradation behaviour of glass fibre reinforced epoxy composites. An ultrasonic treatment for 1 h was used to disperse CMCs (1–3 wt%) within an epoxy resin, which was subsequently infused through glass fabrics to develop hierarchical composites containing both macro and micro-scale reinforcements. It was observed that CMC dispersion in the epoxy resin was homogeneous at 1 wt% CMC and further increase in CMC concentrations led to linear increase in both agglomerate size and total agglomerated area. Addition of 1 wt% CMC to the composite matrix drastically changed the glass fibre-epoxy interface and led to a maximum improvement of 65% in interlaminar shear strength, 14% in tensile strength, 76% in flexural strength, 111% and 119% in fracture energy in tensile and flexural modes, 9.4% in impact strength, 13.5% in storage modulus, 21.9% in loss modulus and 13 °C in the glass transition temperature of composites. Therefore, the use of CMCs could be an industrially viable, economical and eco-friendly approach of developing hierarchical glass fibre composites with considerably improved performance. Keywords: Glass fibre composites, Cellulose microcrystals, Fibre-matrix interface, Mechanical properties, Fracture energy, Dynamic mechanical performance