Study on the curing reaction of epoxidized rubber seed oil for eco-friendly composite application

Abstract

Metbylhexahydrophthalic anhydride (MHHPA) was used as a hot curing agent for epoxidizing rubber seed oil (ERSO and ERSOe) with the presence of methylimidazole (NMI) catalyst. The effect of MHHPA, NMI, glycerol content and temperature on hardening process was studied through the peak exothermic temperature of the curing reaction. Moreover, differential scanning calorimetry analysis (DSC) was used to calculate a curing degree versus reaction time. The obtained optimal conditions (the molar ratio of epoxide group to MHHPA: 1.05/1; the content of NMI and glycerol: 3 wt% and 1.5 wt% of total weight of the resin and MHHPA; curing temperature of 140 and 160 °C for ERSOe and ERSO matrix, respectively) were used for manufacturing the eco-friendly composites. The results showed that this study could open up the new pathway of replacing a petroleum-derived hazardous unsaturated polyester resin with the eco-friendly epoxidized rubber seed oil in manufacturing the composite.