| Abstract: | The oxidation of a hydrogenated butadiene-acrylonitrile (2:1 mole ratio) rubber has been examined by infrared (IR) spectroscopy and the use of γ-initiation to give a controlled initiation step. The resolution and sensitivity of the IR technique was enhanced by the use of chemical derivatization in which carboxylic acids were measured as acid fluorides, hydroperoxides as nitrates and alcohols as nitrites. In all of these compounds, their spectra are sensitive to the precise substituents (primary, secondary or tertiary). Oxidation produced hydroperoxides from both tert. H-C-C=N and sec. H-C-H groups (≈︁1:1.1 mole ratio) as well as chain-end carboxylic acids -CH2-C(=O)OH]. From a comparison with measurements of peroxyl radicals produced at low temperature, average kinetic chain lengths for the various oxidation products were estimated and compared with these from other ethylene copolymers. |
