The role of various indexes of silica in application


Double click auto scroll release time: July 24, 2018 read: 1343 times [font: large, medium and small]


White carbon black is more and more widely used in various industries as an additive, catalyst carrier, petrochemical industry, decolorizing agent, matting agent, rubber reinforcing agent, plastic filling agent, ink thickening agent, metal soft polishing agent, insulation and heat insulation filler, high-grade daily cosmetics filler and spraying material, medicine, environmental protection and other fields. It also provides new material basis and technical guarantee for the development of relevant industrial fields.


1. Specific surface area


The reinforcing effect of white carbon black mainly depends on its specific surface. Generally, with the increase of specific surface area, all strength indicators of rubber products increase, but the resilience decreases, the tear strength decreases, and it is not wear-resistant, difficult to disperse during mixing, high heat generation, large Mooney viscosity of rubber and easy to scorch. Therefore, different formulations and uses require different specific surface areas, The effect of specific surface area on the physical and mechanical properties of vulcanized rubber is not consistent.


2. Oil absorption value


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


3. Ignition loss at 900 ℃


It shows that when there are too many surface hydroxyl groups, it is easy to cause the structure of rubber composites and make the materials brittle. The processing performance is affected, and the vulcanizate is easy to fall off, and the surface hydroxyl group has a strong adsorption effect on the vulcanization accelerator, extending the vulcanization time.


4. 105 ℃ heating reduction


It reflects the amount of free water in the particle gap. If the amount is too small, the structural degree of the rubber is high, and it becomes difficult to make rubber. If the heating reduction is zero, the white carbon black is useless, and it is generally appropriate to control it at about 6%.


5. PH value


Generally around 7, when the pH value increases (the acidity decreases), the vulcanization speed of the compound is accelerated.


6. Soluble salt


The less, the better, but the less, the higher the cost.