Aging of ethylene-propylene diene rubber (EPDM) vulcanized by γ-radiation

The influence of different polyfunctional compounds on the radiation vulcanization of ethylene-propylene diene monomer (EPDM) rubber was investigated. The effect of different antioxidants and their mixtures on the thermal aging and accelerated weathering of gamma-radiation vulcanized EPDM rubber was also investigated. The compounds used were synergistic blends of phenolic and phosphite antioxidants, i.e. 1:4 Irganox era 1076:lrgafos 168, and a blend of arylamine and quinoline type antioxidants, i.e. 1:1 IPPD:TMQ, at different concentrations. The Tinuvin 622 LD hindered amine light stabilizer was also used. The response was evaluated by the tensile strength and elongation at break of irradiated samples after thermal aging at 100 degrees C for 28 days and accelerated weatherings (Xenon test) up to 200 h. The correlations between the type of antioxidant, concentration and efficiency were also investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), (C) 2000 Elsevier Science Ltd. All rights reserved.