Effect of Initiator and Accelerator Amounts on Mechanical Properties of Unsaturated Polyester Resin

Abstract

This research focused on the effect of initiator and accelerator amounts on mechanical properties of unsaturated polyester resin (UPR). Methyl ethyl ketone peroxide (MEKP) and cobalt octoate (CoO) were used as an initiator and an accelerator, respectively. The amount of each chemical was varied from 1, 1.5 to 2 phr. In each batch, UPR, MEKP and CoO were mixed, casted and allowed for curing at room temperature for 24 hours. Mechanical properties of the cured samples were then studied. The results indicated that the effects of MEKP and CoO amounts on flexural properties and impact resistance were greater than those on hardness. It was found that UPR samples prepared by using the same ratio of MEKP and CoO exhibited overall mechanical properties better that those prepared with different MEKP and CoO ratios. When all mechanical properties were considered, the results suggested that the best overall mechanical properties were achieved when MEKP 1.5 phr and CoO 1.5 phr were employed.