The physical mechanical properties and dynamic mechanical properties of NBR and BNBR during thermaloxidative aging were compared

The effects of molecular structure on thermal-oxidative aging and dynamic mechanical properties were discussed. The results showed that the physical mechanical properties of NBR and BNBR were similar

and BNBR exhibited better mechanical properties after thermal oxidative aging test. In the dynamic mechanical properties test

the polarity of NBR is stronger than BNBR

the interaction force is greater

the rotation of single bond is more difficult

and the flexibility of chain is worse. At the same time

the BNBR has flexibility. The dynamic mechanical properties of BNBR at low temperature are better than that of NBR due to these two factors. The degree of crosslinking of the NBR and BNBR is further improved after thermal aging resulting in an increase in the shear modulus. The larger loss factor of NBR is due to the fact that the NBR has a more polar side nitrile group

The internal friction is further increased and the loss factor is further improved after thermal aging.