Thermally stable metal-containing epoxy polymers from an epoxy resin-Schiff base metal complex-maleic anhydride system

Crosslinking of diglycidyl ether of bisphenol A (DGEBA) with tetradentate and hexadentate Schiff base metal complexes of transition metals and maleic anhydride (MA) was investigated. The crosslinking reaction is proposed to proceed through a complex mechanism. Tetrabutylammonium hydroxide was found to be a suitable catalyst for such reaction. The properties of the resulting metal-containing epoxy polymers investigated were glass transition temperature, thermal stability and tensile strength. The copper-containing epoxy polymer obtained from tetradentate Schiff base metal complexes at the mole ratio of DGEBA:metal complex:MA=1:0.2:0.2 showed Tg at 143°C and tensile strength of 62 N/mm2. The polymer showed good thermal stability comparing to the DGEBA–MA system. Upon heating at 250° C for 48 h, the weight loss of the polymer was 2.8%.