The main principles of silicone surface treatment:
The hydroxyl groups on the surface of inorganic powders are usually hydrophilic and incompatible with organic polymers. Silicone surface treatment can reduce the surface energy of inorganic powders, reduce agglomeration between powder particles, and make them more compatible with polymers and easier to disperse.
Silicone products mainly play two roles:
· 1. Improve the dispersion of aggregates.
· 2. Improve polymer-powder compatibility to improve wetting.
The role of silicone surface treatment:
Products treated with silicone tend to have better dispersion, temperature resistance and hydrophobicity. It mainly achieves the above effects through the following methods:
· 1. Improve the adhesion between powder and polymer.
· 2. Enhance the wetting of the powder by the polymer.
· 3. Improve the dispersion of powder in polymer.
· 4. Improve electrical properties and improve mechanical properties.
· 5. Reduce the mixing viscosity of powder/polymer.
Common silicones used in powder processing and their characteristics:
1. Silanes: small molecules, reactive and will not migrate. Often used for product processing with higher requirements
2. Hydrogen silicone oil: excellent reactivity and water repellency
3. Hydroxy silicone oil: has certain reactivity, temperature resistance and dispersion
4. Emulsion products: Modified silicone oil emulsions and their mixtures, different additives can be added according to requirements. Lotion products are easy to use, environmentally friendly, cost-effective and efficient
