NAUGARD™ PHR is a phosphite antioxidant that protects polymers from degradation resulting from heat and oxygen exposure during processing. It also acts as a stabilizer for synthetic rubbers, such as SBR, BR, and NBR, and prevents resinification during manufacturing and storage. NAUGARD™ P and  NAUGARD™ PHR   may be interchangeable, with  NAUGARD™ PHR  being utilized when hydrolysis may occur.   This particular grade of antioxidants prevents polymer degradation during the isolation and drying of emulsion rubbers, such as styrene-butadiene rubber (SBR) and nitrile butadiene rubber (NBR).