Abstract
Liquefaction of waste lignocellulosic biomass is a viable technology for replacing fossil fuels and meeting sustainable development goals. In this study, bio-based epoxy resins were prepared from polyhydric-alcohol-liquefied cotton stalk by glycidyl etherification. The cotton stalk was liquefied in a polyethylene glycol/glycerol cosolvent under H2SO4 catalysis. Epon 828 and cotton-stalk-based epoxy resins could be cured using methylhexahydrophthalic anhydride as the curing agent, and the curing process was exothermic. The thermal properties and tensile strength of cured resins were investigated to examine the effect of adding cotton-stalk-based resin on the performance of the copolymerized epoxy resin. Further, the liquefied-cotton-stalk-based epoxy resin was blended with Epon 828 at different ratios (10, 20, and 30 mass%) and cured with a curing agent in the presence of 2-methylimidazole catalyst. An increase in the peak temperature and a reduction in the heat of curing and activation energy of the Epon 828 epoxy resin was observed with increasing content of the cotton-stalk-based epoxy resin. The tensile strength (35.4 MPa) and elastic modulus (1.5 GPa) of the highly crosslinked cotton-stalk-based epoxy resin were equivalent to those of the petroleum-based epoxy resin Epon 828.