Study On Basic Characteristics And Application In Rubber Of Domestic Silica

In this article, infrared spectroscopy(IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM),and Laser particle size analyzer were employed to characterized the surface groups,microstructure and size distribution of domestic produced high dispersion silica. Then the correlation of micro structure of silica and properties of compounds and vulcanizates filled with different types of silica prepared according to the standard formulation and practical formulation were investigated by modern test methodssuch as dynamic mechanical analysis (RPA, DMTS), TEM and normal mechanical performance.Acomparison between domestic produce high dispersion silica and the international state-of-the-art highly dispersed silica was also made. Besides, the effect of the types blending ration of silica and carbon black, modification methods (coupling agent, polar rubber) on the microstructure, filler network and dynamic properties of solution SBR were investigated.Compared with the silica from Rhodia, the size of the primary structure of domestic silica grades of HD120and HD165are much larger, and their gel content is very high due to the obvious adhesion phenomenon occurred in the primary particles. And thus, the dispersion of HD120and HD165in the compound is rather poor and the mechanical properties and dynamic properties of the compounds and vulcanizates filled with them are worse than their counterpart. As the particle size is much smaller than their competitors, the domestic silica tend to fly in the air when mixed in the open mill or inner mixer because they are not granulated. Based on the above results, the production parameters for high dispersion silica were optimized accordingly and micro pearl granulation technology was employed. The micro structure of the brand new high dispersion silica165MP and120MP are very similar to the products of Rhodia, and thus their performance in in low rolling resistance tires tread formulationand winter tires tread formulation are excellent.The results show that the reinforcing effect is enhanced by the combination of silica and carbon black. The hardness,Modulus at100%,Modulus at300%and tensile strength of the SSBR vulcanizates filled with silica and carbon black increases with the increasing silica content in the combination,while the elongation at break decreased. When the ratio of silica/carbon black was30/20, the tear strength, comprehensive mechanical properties and dynamic mechanical properties of SSBR vulcanizates reached the optimal state, the vulcanizates has lower rolling resistance and better wet-skid resistance.The difference of carbon black and silica particles in the rubber matrix was very obvious under TEM. After modified by Si69, the dispersion of silica in the rubber matrix is very evenly.In silica/carbon black filled compounds, the interface between filler and rubber matrix was vague as a result of good dispersion of the fillers.Silica filled compounds modified by silane NXT has the best processing security, lower heat build-up and permanent deformation; silica filled compounds modified by silane Si747manifest good wet grip and low rolling resistance; Silica filled compounds modified by silane Si69has excellent mechanical properties.The properties of carbon black/silica filled SSBR compounds can be improved by the addition of polar rubber such as CR and NBR. In SSBR compounds, with the increasing of content of polar rubber, the cure rate is improved; the hardness and Modulus at300%increase, the Akron abrasion resistance and heat build-up decrease. The result of TEM analysis showed the dispersion of the silica agglomerates in the rubber matrix can be improved, and the filler network can be reduced if the appropriate amount of polar was added.