Progress in development of epoxy resin systems based on biomass resources

Abstract

Bio-based curing agents and epoxy resins have been used extensively for decades to replace petrochemical-based curing agents and epoxy resins due to their low environmental impact, easy availability, low cost and biodegradability. Petrochemical resources are nonrenewable resources; it is difficult to guarantee the sustainable development prospect for long-term exploitation. As a result, resin manufacturers and end-users have shown great interest in the development of low-toxicity renewable substitutes. Natural resources, such as rosin, vegetable oils, lignin and chitosan, are an abundant source of precursors for producing curing agents and epoxy resins. The present review mainly focuses on the recent advances in various chemical modifications of bio-based precursors, synthesis of various curing agents and epoxy resins and their performance and applications in comparison with that of petrochemical-based curing agents and epoxy resins. Bio-based curing agents should be viewed on the entire supply chain including feedstock and final products to achieve the best sustainability gains.