Coupling agents can improve durability

Coupling agents can improve durability, which can be attributed to the following aspects.

1. The adhesive interface forms chemical or hydrogen bonds, making the interface stronger and more stable.

2. Changed the bonding performance between epoxy resin and filler, increasing the cohesive strength of the adhesive layer.

3. A new interface has been formed between the epoxy adhesive and the adhesive with polysiloxane, preventing moisture and dampness from penetrating the interface. With a barrier layer, the ability to resist environmental corrosion has been enhanced.

4. The coupling agent reacts with the epoxy resin and the adhered surface to form chemical bonds, increasing the adhesive force and enhancing the bonding strength.

5. The coupling agent reduces the viscosity and surface tension of the epoxy adhesive system, and improves the wettability of the adhered material.

6. Can reduce or eliminate internal stress on the interface. Coupling agents have selectivity, which means that they cannot be applied to any system, but need to be matched. In addition to selecting based on the reactivity of the organic functional groups of the coupling agent with the epoxy resin, the acidity and alkalinity of the system also need to be considered. Generally speaking, for acidic polymer epoxy resins and acidic fillers (silica), it is best to choose alkaline coupling agents; On the contrary, for alkaline fillers such as alumina and calcium carbonate, it is advisable to use acidic coupling agents. Therefore, the selection of coupling agents should consider both the chemical bonding effects and the physical effects of acidity and alkalinity. Coupling agents have the best effect on high-energy smooth metal and non-metal surfaces, but are basically ineffective on rough and low-energy surfaces.