Thermal-oxidative Aging Performance of TBIR Modified NR/BR Vulcanizates in Aircraft Tire Sidewall

The thermal-oxidative aging performance of a new generation synthetic rubber trans-1,4-butadieneisoprene copolymer rubber(TBIR) in NR/BR vulcanizates was studied. Compared with the NR/BR vulcanizates, the crosslinking density of NR/BR/TBIR vulcanizates with 10 to 20 per hundreds of rubber(phr) TBIR improved significantly as while as the tensile properties changed little. The heat build-up reduced by 2. 2-3. 4 degrees C and the flexural fatigue resistance increased about 100%. The filler dispersion improved and the average aggregate size of the filler reduced. With the increasing of thermal-oxidative aging time, the crosslinking density of vulcanizates increased and then decreased. The crosslinking density of NR/BR/TBIR vulcanizates remained unchanged after 48 h. With the increasing of aging time, the heat build-up first decreased and then increased and NR/BR/TBIR vulcanizates has the lowest heat build-up value. The flexural fatigue lifetime of NR/BR/TBIR was better than NR/BR vulcanizates.