Brake pads performance analysis: Influence of polydimethylsiloxane (PDMS) viscosity on tribological efficiency

Friction materials are crucial in engineering, particularly in the automotive and industrial sectors where they are extensively used in brake systems. Lubricants are essential in these brake pad materials because they provide friction stability and reduce wear, especially at high temperatures. Polydimethylsiloxane (PDMS), known for its thermal stability and low volatility, is a lubricant in automotive brake pads. However, the effect of PDMS viscosity on the tribological behaviour of brake pads and their overall braking effectiveness is not well understood. This study examines the effect of PDMS viscosity on the tribological properties of eco-friendly brake pads reinforced with benzoyl-treated Pseudoxytenanthera stocksii (P. stocksii) bamboo rhizomes. Brake pads were fabricated with varying viscosities of PDMS and subjected to detailed physical, chemical, mechanical, and tribological testing. Tribological tests were conducted using a CHASE tribometer under controlled conditions, following SAE J661a standards. The results reveal a significant relationship between PDMS viscosity and the tribological properties of the brake pads. Specifically, low-viscosity PDMS emerged as a highly effective additive, demonstrating superior tribological performance compared to higher-viscosity variants. Conversely, higher-viscosity PDMS improved lubrication, leading to a lower coefficient of friction and reduced wear rates. This research underscores the importance of PDMS, particularly in its low-viscosity form, in enhancing the tribological properties of friction composites in brake pad formulations.