The curing characteristics and properties of bisphenol A epoxy resin/maleopimaric acid curing system

Abstract

Epoxy resins are widely used as insulation materials for power systems and are mainly prepared from petrochemical materials, which have the disadvantage of being non-recyclable and environmentally harmful. In this paper, the maleopimaric acid (MPAc) curing agent was prepared from a renewable resource, rosin, and blended with a petroleum-based curing agent (methylhexahydrophthalic anhydride) to cure bisphenol A epoxy resin. The effects of the blending ratio on the curing characteristics as well as on the thermal, mechanical, and electrical properties of the epoxy resins were examined. From the results obtained, as for thermal properties, the introduction of MPAc enhanced the rigidity, glass transition temperature, and thermal decomposition temperature. As for mechanical properties, the brittleness was increased while the tensile strength and bending strength were weakened. When the mass fraction of MPAc was 20–30 wt%, the electrical properties reached the optimum, meeting the application requirements of electrical equipment. This study shows that using rosin-based curing agent maleicpine acid (MPAc) as a partial replacement for petroleum-based curing agents can make electrical equipment environmentally friendly, demonstrating the potential application prospects of rosin-based epoxy resins.

Keywords

• Maleopimaric acid
• Rosin
• Bio-based polymers
• Bisphenol A epoxy resin
• Electrical properties