Evaluation of Curing Agents Using DSC

摘要

In order to investigate the influence of the chemical structure of curing agents on the curring properties of unsaturated polyester resins (UP), the decomposition behavior of organic peroxides (OPs) and curing behavior of UP were estimated using differential scanning calorimetry (DSC). Many kind of OPs (ketone peroxides, peroxyesters and peroxyketals) were evaluated at different curing conditions (room-, medium- and high-temperature curing). In the case of room-temperature curing, methyl ethyl ketone peroxide (MEKP) which is a mixture of reactive organic peroxides (monomer, dimer and trimer peroxide) in dimethyl phthalate is commonly used in combination with cobalt accelerator. Each OP in MEKP was separately synthesized and its redox decomposition rate and curing behavior of UP were examined. Especially it was observed that dimer peroxide gives higher degree of curing compared with monomer and trimer perioxide. In the case of medium- and high-temperature curing, OPs which have t-hexyl peroxy group in its chemical structure gave faster thermal decomposition rate and higher degree of curing compared with OPs having t-butyl peroxy group. Based on experimental results, curing behavior was simulated using autocatalyzed reaction kinetic model.