Study Of Aging Behavior And Properties Of NR/BR/TBIR Vulcanizates

As a new type of synthetic rubber material,TBIR has excellent fatigue resistance and wear resistance,low heat build-up and low rolling resistance performance.Because of the unique butadiene-isoprene copolymer structure of TBIR,applying TBIR to NR/BR system can increase the compatibility of NR and BR,the TBIR crystal fiber can inhibit the carbon black.Combined with other rubber system,such as NR,SBR or NR/BR,SBR/BR,the dispersion of carbon black can be increased and the aggregation of carbon black can be inhibited.TBIR compound is widely used in various rubber products like tread compound,sidewall compound,inner liner,belt layer and other parts of automobile tire to obtain better rubber materials.In the processing,storage and use of rubber products,due to the influence of external environmental factors,the performance of rubber products will deteriorate and lose its application value,even will threaten the economy and life of users.The research on the aging behavior and properties of rubber can analyze the aging mechanism of rubber,and accordingly slow down the aging of rubber,which has theoretical and application significance.The properties of NR/BR/TBIR composite and vulcanized rubber under different aging time were studied by DSC,physical and mechanical properties,thermal properties,fatigue properties and dispersion properties of carbon black.The application of TBIR in this system can make the compound have higher green strength and hardness.After using 10 phr TBIR,the basic physical and mechanical properties of the compound can be maintained,and the dispersion property of the filler can be improved.The fatigue property and heat generation property of the compound can be greatly improved.The physical and mechanical properties,DMA,SEM,TEM and crosslinking density of CB and Si O₂filled NR/BR/TBIR vulcanizates before and after aging were analyzed.It is found that the elongation at break,tensile strength and fatigue resistance strength of NR/BR and NR/BR/TBIR decrease in the filled system,the heat generation under compression decreases first and then increases,and the wear rate increases continuously.As the cross-linking density increases,the content of polysulfide bond decreases.TBIR can improve NR/BR compatibility and packing dispersion.The properties,molecular structure,crosslinking network structure and phase morphology of NR/BR/TBIR vulcanizates were analyzed by physical mechanical properties,DMA,TEM,FT-IR and crosslinking density.The results showed that the elongation at break and tensile strength of NR/BR and NR/BR/TBIR decreased,the hardness increased,the rebound increased first and then decreased,the crosslinking density first increased and then decreased,the content of polysulfide bond decreased,the phase area of NR and BR decreased,the content of C=C double bond decreased,and the content of oxygen-containing groups such as carbonyl hydroxyl group increased.