Dissolution of perfluoroalkyl oligomers in lubricating oil for enhancing wear resistance and fuel economy

摘要

AbstractPerfluorobutyl‐1,1,2‐tri‐H‐1‐hexene and perfluoroalkyl methacrylate have been solubilized in lubricating oil by single‐step free radically grafting onto poly(ethylene‐co‐propylene). Perfluoroalkyl‐1,1,2,2‐tetra‐H‐ethanol and perfluoropolyether carboxylic acid were solubilized by condensing with poly(ethylene‐co‐propylene)‐g‐glycidyl methacrylate, generating the corresponding perfluoroalkyl ether or ester, respectively. Solubilization of 1,1,2,2‐tetra‐H‐ethanol was also achieved by condensing with poly(ethylene‐co‐propylene)‐g‐2‐isocyanoethyl methacrylate to the corresponding perfluoroalkyl urethane. Scar diameter reductions ranged from 9.4 to 58 using perfluoro‐modified graft copolymers as determined using the Four Ball Wear Test, although optimum reductions were obtained using perfluoroalkyl urethane‐modified graft copolymers. Moreover, a semiquantitative correlation of scar reductions and thermal instability was determined. Sequence VI engine testing of perfluoroalkyl urethane graft copolymers containing pendant perfluoroalkyl chain lengths of 8.2 and 7.2 had an Equivalent Fuel Economy Index of 4.33