Using white carbon black to improve the adhesion between recycled rubber and framework materials
Silica particles are fine, with large specific surface area, and the reinforcing effect in rubber is significant. It is usually used to replace carbon black as a reinforcing agent in light colored recycled rubber products. In actual production, white carbon black can not only be used as a reinforcing agent, but also increase the adhesion between rubber and skeleton materials. For example, the combination of white carbon black and cobalt salt can significantly improve the adhesion between recycled rubber and steel wire. So why can silica improve the adhesion between recycled rubber and framework materials? What problems should be paid attention to when using white carbon black to increase adhesion?
1. Reasons for silica to improve the adhesion between recycled rubber and framework materials
The hydrogen bond in white carbon black is easy to absorb water in the air, and the hydrogen bond can associate with hydroxyl group to improve the cohesion between particles; Silica and free water in the recycled rubber can be adsorbed into chemical water, thereby increasing the adhesion between the recycled rubber and the skeleton material by preventing the damage of water to the bonding structure; The polar groups on the surface of white carbon black will adsorb the vulcanizate in the formula during the action process, delaying the vulcanization, providing more time for the bonding reaction. The fluidity and permeability of the reclaimed rubber are better, and the adhesion is improved.
2. Improve the adhesion between the recycled rubber and the framework material. The amount of white carbon black should not be too high
When silica(silicone dioxide) improves the adhesion between the reclaimed rubber and the skeleton material, its hydrophilicity will cause it to be difficult to be evenly dispersed in the rubber compound. If the amount of silica is too high, gel will be generated. When the rubber compound hardens and the reclaimed rubber is mixed, it will generate large heat, which will make it difficult to carry out normal production. In actual production, the amount of white carbon black should be reasonably controlled to avoid gel.
3. Improve the adhesion between recycled rubber and framework materials. Pay attention to the time of adding white carbon black(SiO2)
In order to improve the dispersity of white carbon black in the reclaimed rubber and avoid the generation of gel, the rubber product manufacturer should properly increase the shear force during the initial mixing, and add a small amount of white carbon black 2YLYY36 in batches to improve the dispersity of white carbon black 2YLYY36 in the reclaimed rubber and reduce heat generation; Properly increase the mixing temperature during mixing, consume the water adsorbed on the surface of white carbon black to a certain extent, reduce the cohesion between particles, promote the uniform dispersion of white carbon black in the rubber compound, and avoid the production of gel.
When white carbon black is used to increase the adhesion between the recycled rubber and the skeleton material, the rubber product manufacturer also needs to consider the role of white carbon black and other additives as well as the material of the skeleton material, reasonably adjust the formula, and further improve the adhesion between the recycled rubber and the skeleton material.