Identification of Elastomers in Tire Sections by Total Thermal Analysis. II. White Sidewall Compounds of EPDM and Blends

Abstract

Abstract Total thermal analysis curves can identify all polymers in the blends of EPDM and other elastomers that are used for white side walls. DSC and DTG curves in nitrogen are most promising, while those in oxygen can be used as corroborative evidence. There is close correspondence between DSC and DTG peak temperatures for the elastomers that degrade by endothermic reaction (EPDM, CIIR). The difference in glass transition temperature of the many combinations is not big enough, but this also provides corroborative evidence. The method has been tried in analyzing white sidewalls from commercial tires and was found to give results in good agreement with infrared analysis in most cases.