Chemists Build Biobased Resins From Vegetable Oil

Drawing on vegetable oil as a raw material, researchers in France have demonstrated a method for making biobased epoxy resins. The motivation behind the work of Mylène Stemmelen, Vincent Lapinte, and coworkers at the University of Montpellier II is to replace petroleum-derived starting materials and sidestep the use of bisphenol A. BPA is the primary constituent of most epoxies, including those used to line the inside of food and drink cans and in engineered wood products. But the chemical is under scrutiny for its potentially toxic endocrine-disrupting effects (C&EN, June 6, page 13). Chemists have made epoxies partially from vegetable oil before, typically using epoxidized linseed oil (ELO) because it’s already FDA approved for food applications. Those epoxies require an amine curing agent, however, and rely on off-the-shelf petroleum-derived alkylamines. The French researchers instead paired ELO with a polyamine they made from cysteamine and grape-seed oil, Stemmelen reported. They then used heat to cross-link ELO with the amine to form veggie epoxy resins. Stemmelen noted that the thermomechanical properties of the new epoxies made so far aren’t stellar, but ongoing work to modify the polyamine should lead to improved versions.