1, specific surface area
The size of the reinforcing effect of silica depends mainly on the specific surface area of the silica, and the strength index of the rubber product increases, but the rebound resilience decreases, the tear strength decreases, and the wear resistance is not mixed. It is difficult to disperse during refining, has high heat generation, and has a high viscosity and easy scorch. Therefore, different formulations and different applications require different specific surface areas. The specific surface area has no consistent effect on the physical and mechanical properties of vulcanized rubber.

2, oil absorption value
The oil absorption value reflects the degree of structure, the oil absorption value is large, the structure is small, the tensile strength of the vulcanized rubber is generally large, the tensile strength and hardness are large, especially the wear resistance is small, but the elongation is higher. low.

3, 900 ° C burning loss
It is manifested that when the surface hydroxyl group is too much, it is easy to cause the structure of the rubber composite material to make the material brittle. It affects the processing performance, and the vulcanized rubber is easy to fall off, and the surface hydroxyl group has a strong adsorption effect on the vulcanization accelerator, and the vulcanization time is prolonged.

4, 105 ° C heating reduction
It reflects the amount of free water in the voids of the particles. When the amount is too small, the degree of structural structuring of the rubber becomes high. If the heating loss is zero, the white carbon black is useless, and it is generally suitable to control at about 6%.

5, PH value
Generally around 7, the pH value increases (acidity decreases), and the vulcanization rate of the rubber compound increases.

6, soluble salts
The less the better, but the less, the higher the cost.