Lipase‐Catalyzed Synthesis and Curing of High‐Molecular‐Weight Polyricinoleate

High‐molecular‐weight polyricinoleate, with an $\overline M _{\rm w} $ of 100 600, was enzymatically prepared by the polycondensation of methylricinoleate using immobilized lipase from Pseudomonas cepacia (IM‐PC) in bulk in the presence of 4 Å molecular sieves at 80 °C for 7 d. Polyricinoleate was a viscous liquid at room temperature with a glass transition temperature ( T g ) of −74.8 °C, showed no crystallinity and was biodegraded by activated sludge. Polyricinoleate was readily cured using a dicumyl peroxide at 170 °C for 30 min to produce a chloroform insoluble crosslinked polyricinoleate with a hardness of 50A using durometer A.