Tribological interactions of advanced polymeric coatings with polyalkylene glycol lubricant and r1234yf refrigerant

We report on the tribological performance of an aromatic thermosetting polyester (ATSP) blended with polytetrafluroethylene (PTFE) as a coating material for air-conditioning compressor applications. Tribological experiments were conducted in the presence of environmentally friendly r1234yf refrigerant and polyalkyleneglycol (PAG) lubricant, to compare state-or-the-art polymeric coatings with ATSP/PTFE. Results showed better performance for ATSP/PTFE, compared to PTFE-based and Fluorocarbon- based coatings under both dry and boundary lubricated sliding conditions. Significant reduction of 69% in friction was obtained with the inclusion of PAG lubricant, suggesting a synergistic combination for ATSP/PTFE and PAG/r1234yf. Morphological evolution via scanning electron microscopy revealed surface cracks and voids for PTFE/MoS2, responsible for negative interactions under lubricated condition, which was not the case for ATSP/PTFE coating.