Curing Behavior and Thermal Properties of Autocatalytic Cycloaliphatic Epoxy.

Cycloaliphatic epoxy resin containing hydroxyl group (DMTMP) was prepared by the transesterification between methyl-3,4-epoxycyclohexane carboxylate (MEC) and trimethylolpropane (TMP), which was then thermally cured with methylhexahydrophthalic anhydride (MHHPA). As comparison, a commercial available cycloaliphatic epoxy 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (ERL-4221) cured with the same curing agent was also investigated. The chemical structure was characterized by FT-IR and 1H-NMR. And the curing behavior and the thermal properties were studied by DSC and TGA. The DSC results showed that the DMTMP systems exhibited higher reactivity than the ERL-4221 systems due to the autocatalysis of hydroxyl group of DMTMP. While the glass temperature transitions (Tg s) of DMTMP systems were much lower than ERL-4221 systems, and the Tg s of DMTMP and ERL-4221 systems both reduced after introducing n-dodecyl trimethylammonium bromide (DTAB) as catalyst. The decomposition behavior from TGA shows that the DMTMP epoxy resins exhibited a relative slow weight decreasing tendency in comparison with ERL-4221 epoxy resins, but initial degradation temperatures of DMTMP systems were lower than ERL-4221 systems. [ABSTRACT FROM PUBLISHER]