The replacement of ozone-depleting refrigerants with ozone-friendly hydrofluorocarbons (HFCs) requires the use of lubricants that have not historically been used in refrigeration compressors and systems. Polyalkylene glycol (PAG) and polyol ester (POE) lubricants have been extensively evaluated in various refrigeration applications and are being used commercially. Novel synthetic lubricants have been developed based on polybasic esters (PBEs) resulting from malonate-acrylate Michael adducts. These lubricants were designed to address problems encountered in current HFC systems. PBE-based fluids show desired miscibility with R134a and other HFC blends, excellent hydrolytic stability, no copper plating (even in wet systems), and excellent lubricity. All of these properties are obtained without the use of performance-enhancing additives. Presents key physical property data, bench and compressor test results, and compatibility study results.

KEYWORDS: year 1995, replacing, refrigerants, lubricants, compressors, refrigeration, performance, stability, testing, properties