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

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 (Tg), 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, Tg, and mechanical properties. © 2004 Society of Plastics Engineers