Application method of commonly used coupling agents for fillers

The effect of coupling agents on modifying fillers has been introduced many times. Currently, the most widely used coupling agents are silane coupling agents, titanate coupling agents, aluminate coupling agents, and other types of coupling agents. Therefore, when choosing a coupling agent, we need to select the corresponding coupling agent for different fillers.

Different fillers result in significant differences in coupling effects. Therefore, the editor will introduce the selection and use of coupling agents - applicable filler types as follows.

1. Suitable fillers for silane coupling agents

Silane coupling agents have significant effects on silicon dioxide, aluminum oxide, glass fiber, clay, silicate, silicon carbide, etc., but have slightly poorer effects on talc powder, clay, aluminum hydroxide, wollastonite, iron powder, aluminum oxide, etc. They have little effect on asbestos, titanium dioxide, iron oxide, etc., and have little effect on calcium carbonate, graphite, carbon black, barium sulfate, calcium sulfate, etc. The coupling effect of silane coupling agent is greater for fillers with silanol groups on the surface, while for carbonates, sulfates, sulfites, etc. of calcium, magnesium, and barium, the coupling effect of silane coupling agent is not very obvious. If the surface of filler particles without silanol groups is treated with silica sol and then silane coupling agent is used, a good coupling effect will be achieved. This treatment method is called double coating method.

2. Suitable fillers for titanium ester coupling agents

Both titanium ester coupling agents and aluminum ester coupling agents can treat the surface of fillers, but the treatment effects are somewhat targeted. Fillers with good treatment effects of titanium ester coupling agents include calcium carbonate, barium sulfate, calcium sulfate, calcium sulfite, aluminum hydroxide, magnesium hydroxide, calcium silicate, aluminum silicate, titanium dioxide, asbestos, aluminum oxide, iron oxide, lead oxide, ferrite, etc; Fillers with slightly inferior processing effects include mica, silica, magnesium oxide, calcium oxide, etc; Fillers with poor processing effects include talc powder, carbon black, and wood powder;