Oxidation of rubbers analysed by HATR/IR spectroscopy

The presence of large amounts of carbon black in number of industrial applications of rubbers makes their analytical study by infrared spectroscopy difficult, particularly their chemical evolution upon ageing. The present paper reports the use of a Horizontal Attenuated Total Reflectance accessory equipped with a germanium crystal. HATR (Ge) /FTIR analysis of both thermal-and photooxidations of EPDM, CR and NBR were first validated by conventional transmission spectroscopy in the absence of carbon black. Then, HATR (Ge) was used with fully formulated rubbers with the aim of studying their long term behaviour. Influence of temperature, UV exposure, carbon black or stress as well as the oxidation profile across the materials or the identification of carboxylic acids/ carboxylates groups have been examined. (C) 1998 Elsevier Science Limited. All rights reserved.