Curing Behavior and Thermal Properties of Autocatalytic Cycloaliphatic Epoxy

Abstract

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 (T_g s) of DMTMP systems were much lower than ERL-4221 systems, and the T_g 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.

Keywords:

• Cycloaliphatic epoxy
• autocatalytic
• curing behavior
• thermal properties

Acknowledgments

This research was financially supported by the program of building Industry Engineering Technology Center (No. [2008] 6–08) and the rolling program of building Technological Innovation of Modern Industrial System for Guangdong province (No. 20101022108).