Curing and properties comparison of an unsaturated polyester resin, varying crosslinking reaction conditions

Abstract In this work four different curing modes were used to crosslink a general‐purpose unsaturated polyester resin. Styrene was used as monomer and glass fiber mat as reinforcement. The four curing modes included a traditional convection oven, a long‐wavelength infrared (IR) radiation oven, a medium‐wavelength IR radiation oven, or room temperature for an open‐curing condition without oven heating. Some samples were cured using initiator only, and others were cured combining initiator and promoter. For oven curing, chamber temperature was 85°C. For the samples, final curing conversion (using Fourier transform IR spectroscopy), as well as glass transition temperature (T_g), Young's modulus, impact strength, and Shore D hardness were measured and compared. The medium‐wavelength IR radiation oven as curing condition offered the best option for highest conversion, T_g, and mechanical properties. Polym. Compos. 25:662–666, 2004. © 2004 Society of Plastics Engineers.