Filler modification

Fillers have gradually become important organic polymer additives and modifiers, playing an important role in reducing production costs and improving product performance. The hydroxyl groups on the surface of fillers are usually hydrophilic and exhibit incompatible characteristics with organic polymers. For example, alkoxysilane is suitable for treating the surface of minerals. The hydroxyl groups on the surface of minerals condense with the hydroxyl groups generated by silane hydrolysis, and the organic end on the silane faces outward. This makes minerals more dispersed in the polymer, less prone to aggregation, improves the coupling between resin and filler, and even turns the filler into a reinforcing additive. Silanization treatment can improve the process performance, mechanical properties, and durability of products through the following methods:

(1) Enhance the adhesion between fillers and polymers

(2) Improving the impregnation performance of fillers on polymers

(3) Promote the dispersion of fillers in polymers

(4) Improve mechanical performance

(5) Reduce the viscosity of filler/polymer mixtures

The choice of silane to use should be determined based on the preferred characteristics of the desired silane. All alkoxysilanes are easily bound to the surface of fillers or minerals, and the natural acidity and moisture on the surface of some fillers are sufficient to catalyze the complete hydrolysis of silane, so there is no need for additional pre hydrolysis during the filler treatment process.

In the process of surface modification of fillers, the following principles can be followed:

If the purpose of silane treatment is to provide surface hydrophobicity, hydrophobic silanes such as methyl, decyl, octyl, dodecyl, or hexadecyl or phenyl should be selected. It is recommended to prioritize the use of CY-8030, CY-1631, CY-1231, CY-8831, CY-7030, etc;

If the purpose of silane treatment is to improve the compatibility between polymer and filler, the characteristics of organic groups on silane should be similar to the chemical structure of the polymer. For example, in polyolefin mixtures, it is recommended to prioritize the use of CY-1631, CY-1231, etc;

If silane treatment is to bind fillers to polymer matrix, organic reactive silane should be selected, and it is recommended to prioritize the use of CY-570, CY-560, CY-550, CY-792, CY-171, etc.