Comparison of thermo-oxidative aging properties of hydrogenated natural rubber prepared by different metal ion catalysts

Hydrogenated natural rubber (HNR) was prepared by emulsion hydrogenation using different metal ion catalysts. The isothermal oxidation induction time (OIT) of raw rubber and the change of tensile properties of vulcanizate before and after thermal oxidative aging were studied. And the effect of metal ion catalysts on the thermal oxidative aging properties of HNR was investigated. The results showed that the copper ions in the hydrogen peroxide/hydrazine hydrate/copper ion catalytic system had great influence on the thermal oxidative aging properties of the materials. The tensile properties of HNR prepared with copper ions after thermal oxidative aging were higher than those of natural rubber latex, and the OIT was shortened to 2.5 min. The HNR sample prepared after replacing copper ions with zinc ions had better thermal oxidative aging properties, with the change rate of tensile strength reduced to 23.91%, the change rate of elongation at break reduced to 32.12%, and the OIT at 150 ℃ extended to 32.4 min after thermal oxidative aging at 100 ℃ for 72 h.