Dynamic Mechanical Properties Of Silica/CB-Filled Natural Rubber

Precipitated silica is an important reinforcing agent in the rubber industry, it has better reinforcing effect than any other filler but the CB. Since the green tire is produced by Michelin Co, silica filled tread compounds with low rolling resistance and high wet skid resistance attracts wide attention of researchers. With the implementation of the European tire label rule, the tire industry is facing new opportunities and challenges, the research on the green tire has become a pressing issue.The effects of mixing conditions and dispersing agents on the properties of silica/CB filled NR were studied in this paper, the experimental results are as follows.(1)When the total amount of CB and silica is constant, With the increase of silica, the scorch time and curing time increases, the filler network is weakened,mechanical properties of vulcanizates decrease, but the rolling resistance of vulcanizates decreases and the wet skid resistance of vulcanizates increases.(2) With the dumping temperature in two pass mixing increases, the scorch time is shortened and the curing time is increased, the maximum torque and minimum torque are all increased. Dumping temperature has little effect on the Mooney viscosity of compounds. Reinforcing effect of filler increases with the increase of dumping temperature, so do the wet skid resistance and rolling resistance.(3) The three pass mixing compounds has lower Mooney viscosity. The number of mixing pass has no obvious effect on the degree of dispersion of filler in rubber matrix. With the increase of number of mixing pass,reinforcing effect of filler increases, the wet skid resistance of vulcanizates increases, but the rolling resistance of vulcanizates is little changed.With the dumping temperature in three pass mixing increases, the Mooney viscosity of compounds is increased and the curing time and the maximum torque are all decreased. Dumping temperature has little effect on the scorch time and minimum torque. Dumping temperature has little effect on the mechanical properties and dynamic properties of vulcanizates. The vulcanizates obtained in two pass mixing has a better abrasion resistance.(4)For the CB filled NR, the compounds with dispersing agents has lower Mooney viscosity and the energy consumption in mixing is lower. For the silica filled NR, the vulcanizates with dispersing agents have better mechanical properties, the Mooney viscosity of compounds and energy consumption in mixing are all decreased.