Evaluation of epoxy resins synthesized from steam-exploded bamboo lignin

Lignin extracted from steam-exploded bamboo has been used as resource material for the production of cured epoxy resins. In this study, 3 types of cured epoxy resin were prepared. The bamboo lignin extracted with methanol from steam-exploded bamboo (steam pressure 35 atm; steaming time 5 min) was epoxidized with epichlorohydrin and then cured with the general curing agent 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole (2E4MZ-CN) and bamboo lignin. General epoxy resin, cured with diglycidyl ether bisphenol A (DGEBA) and 2E4MZ-CN, was simultaneously synthesized as a petroleum-derived epoxy resin control. The mechanical and thermal properties of lignin-based epoxy resins were compared with petroleum epoxy resins. As indicated by their thermal decomposition properties (Td5), the lignin-based epoxy resins exceeded the dip-solder resistance (250–280 °C). Furthermore, lignin-based epoxy resin showed 70% of the flexural strength of the petroleum-based epoxy resin.