Green ester lubricants based on rapeseed acid and their lubricity

Several complex esters were synthesized from phthalic anhydride, neopentyl glycol and rapeseed acid. Their rheological properties, biodegradability and tribological properties were measured. It was found that the complex esters have a wide viscosity range of 126 similar to 325mm(2)/s at 40 degrees C with viscosity indices about 127 similar to 143, and solidifying points. lower than -38 degrees C. The maximum non seizure load of a complex ester with degree of polymerization 1.42 is as high as 735 N, with a wear scar diameter of 0.41mm, superior to mineral oil. The biodegradation rates are higher than 73%, and the thermal stability is good. So these complex esters are a class of green synthetic ester oils with excellent properties.