Multifunctional lubricant additive derived from polyisobutylene succinimide dispersant

A new multifunctional lubricant additive (PIBSI-BSb) was synthesized by modifying polyisobutylene succinimide dispersant (PIBSI) with borated Schiff base. The results show that the antiwear and antioxidant properties of PIBSI were improved by modification with borated Schiff base, but the dispersibility was not decreased. Compared with PIBSI, the oxidation induction time (OIT) of PAO containing PIBSI-BSb was prolonged by 6.26 times, and the mean wear volume of steel ball lubricated by the PIBSI-BSb was reduced by 79.1%. The worn scars of steel balls were analyzed by SEM, EDS and XPS. The tribofilm consists of B2O3, FeO, N-containing organic compounds and iron fluoride, which indicates that the B and F atoms of PIBSI-BSb improve the antiwear capabilities.