The role of each index of precipitated silica(SiO2) in the application
1.specific surface area
The size of the reinforcing effect of white carbon black mainly depends on the increase in specific surface area of its specific surface, and the strength index of the rubber products increases, but the resilience is reduced, the tear strength is reduced, and it is not wear-resistant, the dispersing is difficult, the heat is high, the viscosity of the rubber is high, and the coke is easy to burn. Therefore, different formulas, different The specific surface area of the vulcanizate is different, and the specific surface area does not affect the physical and mechanical properties of vulcanized rubber.
2. The value of oil absorption of silicon dioxide
The size of the oil absorption value is the structure degree, the oil absorption value is large, the structure degree is small, the tensile strength of the vulcanizate is generally large, the tensile strength and the hardness are large, especially the wear resistance is smaller, but the elongation is low.
Burn reduction at
3. 900 degrees centigrade
When the surface hydroxyl is too high, it is easy to make the rubber composite material structure and make the material brittle. It affects the processability, and the vulcanizate is easy to fall off, and the surface hydroxyl has strong adsorption on the vulcanization accelerator and prolongs the curing time.
4.Heating reduction at 105 degrees C
The amount of free water in the space of particles is reflected. When it is too small, the structure of the rubber is difficult. If the heating reduction is zero, the white carbon black is useless, and the general control is about 6%.
5, pH value
Generally around 7, pH increases (acidity decreases), and rubber vulcanization speeds up.
6. Soluble salt
The less the better, the less, the higher the cost.