Lipase-catalyzed synthesis and curing of high-molecular-weight polyricinoleate

High-molecular-weight polyricinoleate, with an M̄_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 cross-linked polyricinoleate with a hardness of 50A using durometer A.