Synthesis of vegetable oil-based furfurylamine-derived monomer and its polymerization behaviour

Vegetable oils (VOs) are regarded as important bio-based raw materials due to their wide availability, low cost, renewable nature, and flexible functionalization and modification. In this work, a series of VO-based furfurylamine-derived monomers were synthesized via a solvent-free aminolysis reaction with 2-furfurylamine (FA), which involved a rigid furan ring and fatty amide with a flexible aliphatic chain. These monomers retain favourable renewability, degradability, and processability of bio-based feedstocks, while obtaining enhanced reactivity and rigidity from the furan moiety. As a proof of concept, the uncatalyzed aminolysis reaction between soybean oil (SO) and FA was performed at 90 °C and reached equilibrium after 72 h, giving soybean oil-based furan amide (SO-FA) with an ester group conversion of 61%. As an organocatalyst, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD, 1.5 wt%) could dramatically accelerate the aminolysis process, achieving 87% conversion within 3 h at 80 °C. Subsequently, a bio-based poly(soybean oil-based furan amide-co-maleic anhydride) (PSOFM) was prepared by copolymerization of SO-FA and MAH, and PSOFM₁ with 56% yield and number average molecular weight (M _n) of 9200 g mol^-1 was obtained under optimized reaction conditions. Due to the participation of double bonds within the fatty acid chain during copolymerization, PSOFM copolymer with branched structure was formed, and higher unsaturation content led to increased molecular weight and broader molecular weight distribution. This work presents a facile and efficient strategy for synthesis of VO-based monomers and corresponding functional polymers from readily available biomass.