Synthesis and evaluation of polyisobutylene-ionic liquid dispersant for carbon stabilization in oil

Abstract The development of advanced dispersants is crucial for addressing the challenges of modern engine oils, particularly in stabilizing soot particles, minimizing sludge formation, and maintaining performance under extreme conditions. PIBILs (polyisobutylene-based ionic liquids) represent a significant advance in dispersant technology because of their amphiphilic structure and unique properties. With their outstanding thermal stability, high ionic conductivity, and structural versatility, ionic liquids can be fine-tuned to meet specific performance requirements. This study focuses on the synthesis of PIBIL dispersants through the reaction of polyisobutylene succinic anhydride (PIBSA) and trihexyl(tetradecyl)phosphonium decanoate at a 4:1 molar ratio and evaluates their performance in stabilizing soot particles and enhancing oil properties. Comprehensive characterization using Fourier Transform Infrared spectroscopy (FTIR), Gel Permeation Chromatography (GPC), and Thermogravimetric Analysis (TGA) confirmed their robust thermal stability and molecular integrity. At optimal concentrations (3–5 wt.%), the dispersant reduced carbon particle aggregation by over 50%, decreased surface tension by 15%, and exhibited thermal stability up to 400°C. Tribological tests revealed a 30% reduction in friction and significant wear protection through the formation of durable boundary layers. These findings underscore the potential of PIBILs as multi-functional additives, leveraging the advantages of ionic liquids to address critical challenges in engine efficiency and environmental sustainability. This innovative approach could redefine dispersant applications in engine oil formulations, contributing to cleaner, more efficient, and longer-lasting engines.