Interaction Between Carbon Black, Silica And Rubber And Their Influence On Performance

In this dissertation, interaction between carbon black and vulcanization, interaction between carbon black, silica and rubber and their influence on processing and mechanical properties of corresponding NR and SBR compounds and vulcanizates were extensively investigated and the following results were obtained.There was an apparent synergism between vulcanization and reinforcement on the improvement of shear modulus of NR compounds and vulcanizates. The re-agglomeration of CB aggregates during vulcanization and the elastic recovery of vulcanizates helped the reformation of broken CB network.which amplified the Payne effect.The analysis on cure torque of NR with different load of CB showed that there was a good linear relationship between delta torque and carbon black filling load which indicated than CB had no influence on the chemical crosslinking of NR. The equilibrium swelling experiments and crosslink density analysis with NMR technique of filled and unfilled NR vulcamizates went to the same conclusion.As to mixing sequence, the addition of minor ingredients such as accelerator, activator and antioxidant prior to the addition of CB improved the dispersion of CB. The energy consumption was the lowest and both the processing and mechanical proerties were improved.The higher polarity of silica contributes to the strong formation of filler network at even lower filling load than CB. The chemical reaction between coupling silane, silica and rubber changed the interaction mechanism between silica and rubber which decreased the dynamic hysteresis of vulcanizates. The SEM results showed that the chemical bonding between silica and rubber stabilized the silica network under cyclic deformation which lowered the tendency of regglomeration of silica aggregates.The dosage of DPGin silica filled SSBR depends on the specific surface area of silica. The higher surface area deserved more DPG amount. The optimium DPG amount for SSBR filled with 60 patrs 1115MP was1.5parts. Even in the absence of sulfur, Si-69 can crosslinked with rubber in the presence of accelerator. So accelerator should be added later to avoid pre-vulcanization. The same reaction didn't occurred in system with NXT ascoupling agent.