Linoleic acid (LA) was extracted and purified from Idesia polycarpa Maxim.var. vestita Diels (IPMVVD) oil by urea adduction fractionation, and the response surface methodology (RSM) was successfully employed to optimize the process. The optimal conditions for purification of LA from mixed fatty acids by urea adduction fractionation were as follows: a weight ratio of 4.4:1.0:1.0 (w/w/w) of methanol/urea/mixed fatty acids, a temperature of -5°C and a time of 24.6 h, respectively. Under these conditions the experimental LA yield (48.65%) agreed with the predicted value and the purity of LA was 98.74%.

The chemical modified Idesia polycarpa Maxim. var. vestita Diels (IPMVVD) oil as a biodegradable lubricant was described in the paper. IPMVVD oil was modified by epoxidation and reaction of ring opening to resolve poor oxidative stability and low-temperature fluidity when vegetable oils as lubricants directly. The effects of the parameters in the process were studied, and then the product was evaluated. The results showed that the modified IPMVVD oil had higher viscosity index and superior oxidative stability comparing with unmodified oil; its mixtures with Dioctyl phthalate (DOP) offered a wide range of kinematic viscosities and lower pour point (-22°C), displayed preferable low temperature performance.