Short-term evaluation of the thermal endurance characteristics of polymeric materials by TA

Two thermal analysis techniques (isothermal differential calorimetry and isothermal thermogravimetric analysis) are used as analytical methods for short-term thermal endurance characterization of polymeric materials, used for electrical insulation. These techniques are applied to commercial grade ethylene-propylene rubber and polyvinyl chloride. It is shown that thermogravimetric analysis provides very satisfactory results, independently of the degradation reactions which take place in the material. Calorimetry proves to be effective only for polymers (such as polyolefins) in which oxidation is the largely prevailing degradation mechanism in the test and service temperature ranges.