Effect of Additives on the Rheological Properties of Fast Curing Epoxy Resins

Abstract

rapid resin transfer molding (rtm) process is suitable for high-throughput manufacturing of complex-shaped composite parts. ideally the epoxy system should exhibit low viscosity and long gel time at room temperature for quick mold filling, and very fast curing once the resin is inside the heated mold. the present research was performed on different epoxy formulations by varying the concentrations of diluent and catalyst. rheological studies were carried out to measure the flow viscosity and to determine the gel time at different temperatures. it is noted that the addition of diluent effectively decreases the viscosity of formulation, and the addition of imidazole affects the rate of epoxy cure. several epoxy resin formulations were studied and compared with the commercially available infusion-grade epoxy system of Araldite Ly 8601/Aradur 8602. the results show that epoxy systems such as that containing 5% imidazole and 10% reactive diluent are suitable for the rapid rtm process with balanced flow and cure characteristics.