The role and effect of Fluorosilane coupling agents have been recognized and affirmed by people, but why a very small amount of coupling agent on the interface has such a significant impact on the performance of composite materials, there is still no complete coupling mechanism to explain why .
There have been many studies on the action mechanism of Fluorosilane coupling agent on the interface between two materials with different properties, and explanations such as chemical bonding and physical adsorption have been proposed.
There are many varieties of Fluorosilane coupling agents. The Y groups in the general formula are different, and the types of polymers suitable for the coupling agent are also different. This is because the group Y has a selective reaction to the polymer, such as containing vinyl and Methacryloyloxy silane coupling agent is particularly effective for unsaturated polyester resins and acrylic resins.
The reason is that the unsaturated double bond in the Fluorosilane coupling agent and the unsaturated double bond in the resin undergo a chemical reaction under the action of the initiator and the accelerator. However, when the coupling agent containing these two groups is used for epoxy resin and phenolic resin, the effect is not obvious, because the double bond in the coupling agent does not participate in the curing reaction of epoxy resin and phenolic resin.
However, the Fluorosilane coupling agent of epoxy group is particularly effective for epoxy resin, and because epoxy group can react with the hydroxyl group in unsaturated polyester, epoxy-containing silane is also suitable for unsaturated polyester; The amine group-containing silane coupling agent is effective for epoxy, phenolic, melamine, polyurethane and other resins.