Driven by diminishing fossil fuel resources, global warming and subsequently rigid legislation on CO2 emission, fuel economy is a major challenge for the automotive industry. Each element of the powertrain has been optimized or newly designed to increase efficiency. In this optimization process the engine oils and transmission fluids are important design elements and their contribution to improved efficiency is significant. Polyalkylmethacrylates (PAMAs) are widely used as viscosity index improvers in engine, transmission and hydraulic oils. They have been shown to adsorb from oil solution onto metal surfaces to produce thick and viscous boundary films. These films are maintained even in low speed and high temperature conditions and thus produce a reduction of friction and wear. It was found that specifically designed film-forming PAMAs can improve pitting performance of lubricant formulations. The paper describes the impact of tailor-made functionalized PAMAs on boundary film formation and explores their ability to increase the fatigue life of lubricants.
Keywords: Polyalkylmethacrylates, viscosity index improvers, film-former, fatigue life, pitting