effect of initiator on thermal curing of unsaturated polyester resins

one of the common methods to cure unsaturated polyester resins is to use dual initiators. in order to produce an appropriate composite, it is necessary to know the effect of dual initiators on curing behavior. in this paper the effect of benzoyl peroxide, bpo, and tertiary butyl perbenzoate, tbpb, and their mixtures on thermal curing of an unsaturated polyester resin have been investigated. bpo and tbpb are medium and high temperature initiators, respectively. spi and dsc tests have been used for this evaluation. spi test results show that in curing system containing tbpb/bpo, higher gel time, lower curing peak temperature and lower release heat have been achieved by using higher amount of tbpb. dsc results show that a suitable curing system can be achieved by using a dual initiator system.