Enhanced creep resistance of GFRP composites through interpenetrating polymer network

Abstract

Fiber reinforced polymer (FRP) composites have become promising materials of modern times and find numerous applications in critical engineering fields including aerospace, marine and automobile sector. Due to their increasing demand, it becomes apparently essential to employ advanced techniques, which can predict the long-term behavior of such materials in various in-service conditions. Epoxy and vinyl ester based composites are most commonly used in structural FRP composites. As each polymer has its own advantages and disadvantages, hybridization or blending of different polymers is a trending technology to improve the performance of resulting FRP composite. The present article aims at comparing the performance of glass fiber reinforced epoxy-vinyl ester interpenetrating polymer network (GEVIPN) composite with that of the base materials, i.e. glass fiber reinforced epoxy (GE) and glass fiber reinforced vinyl ester (GVE) composites. Flexural testing has been conducted at various in-situ temperatures (30 °C, 60 °C and 90 °C) where GEVIPN composite showed highest properties at 30 °C. The lifetime prediction of the composite materials has been carried out using accelerated deformation and time-temperature superposition (TTSP) principle. It was observed that GEVIPN composite showed highest creep resistance as compared to the other two composites at lower temperature, whereas opposite trend was observed at elevated temperature. At 30 °C, GEVIPN composite showed positive reinforcement efficiency for ∼385 days with respect to GE and ∼46.27 years with respect to GVE. Similar studies were done for the other reference temperatures. Following this, fractography analysis of the fractured surface was done under FESEM to identify the failure mechanisms and draw a comparison between the composites.