In practical applications, not only RTV silicone rubber is required to have high bonding strength and good elasticity, but also requires good construction performance to meet the requirements of fine surface or groove, inclined or vertical surface construction. Therefore, the adhesive should not flow, that is, it must have contact. transsexual. Fluid thixotropy refers to the fact that under the action of a fluid, the microscopic net-like structure changes with the shear time, and the macroscopically shows the phenomenon of shear thinning. At present, there is a lack of unified explanation of the various thixotropic mechanisms. Scholars at home and abroad are still studying it, but it is an indisputable fact that nanometer calcium carbonate can improve the thixotropy of RTV silicone rubber.

 Xie Wenqing wet-modified the nano-calcium carbonate with a composite modifier. The results show that the nano-carbonate particle size is smaller and the distribution is more uniform than that of the stearic acid modifier. The consistency of the silicone rubber prepared by the nano-calcium carbonate modified with the composite modifier is 8.6, which is lower than the consistency of the silicone rubber prepared by the nano-calcium carbonate modified by sodium stearate. The consistency index can initially reflect the contact of the silicone rubber. Silicone rubber with variable properties, low consistency, and good extrusion properties indicates that its thixotropic properties are better.

Chen Litang filled the silicone sealant with nano-calcium carbonate compounded with different content of fatty acids. With a certain amount of nano-calcium carbonate, with the increase of the nano-calcium carbonate surface treatment agent, the extruding property of the finished glue became significantly better. From the experimental results, it can be seen that when the amount of the surface treatment agent is 3% to 4%, the performance of the nano calcium carbonate is better.

Liu Yaxiong studied nano-calcium carbonate-filled silicone rubber treated with different particle sizes and different modifiers. The results show that the larger the specific surface of nano-calcium carbonate, the smaller the average particle size, and the greater the interaction between the particles, reflecting the gel The viscosity of the material increases, the thixotropic index increases continuously, and the amount of extrusion decreases. The hydrocarbon chain on the surface of organically treated calcium carbonate can interact with nearby hydrocarbon and siloxane chains to form a stable spatial network structure. Under the action of shear force, this network structure is broken, showing a decrease in viscosity, easy extrusion, and positive thixotropy. When the shearing force stops, this network-like space structure is formed by re-entanglement of Van der Waals force and hydrocarbon chain, showing good anti-sag resistance. Based on the rheological properties of silicone rubber, it is better to control the specific surface of nanometer calcium carbonate with 22 ~ 30 m2 / g by using lauric acid and stearic acid.