The Application of silane coupling agent on resin matrix composites
In 1947, Ralph K. Witt and others at Johns Hopkins University in the United States discovered that allyltrimethoxysilane treatment has excellent enhancement effect on glass fiber on unsaturated polyester composites, thus creating the history of practical application of silane coupling agent. The resin composite material is the earliest and most basic application field of the silane coupling agent.
When glass fiber or mineral reinforced organic polymers are used, the interfacial bonding between the polymer and the inorganic material is critical to the mechanical properties and durability of the resin matrix composite, and one of the most important factors is the water erosion interface, which destroys Bonding.
The silane coupling agent can form a water-resistant bond at the interface between the inorganic and organic materials, which not only enhances the bonding strength, but more importantly, it prevents the bond disintegration at the interface during aging and use of the composite. In composite materials, the choice of a suitable silane can increase the flexural strength of the composite by more than 40%, and significantly enhance the resistance to humidity and other vicious environmental conditions.
The choice of different silane coupling agents has a huge impact on the performance of the product, for example as follows:
Effect of Different Y Organic Functional Silanes on Flexural Strength of UP FRP
|
Silane model |
Dry state，MPa |
Wet state，MPa |
Retention |
|
No silane |
220 |
83 |
38% |
|
Ethyl silane |
157 |
107 |
68% |
|
Vinyl silane |
249 |
220 |
88% |
|
Methacryloxysilane |
314 |
285 |
91% |
Visible from the above table;
1. The silane coupling agent which can be well matched with the resin of the Y organic group can obviously improve the performance of the product, and if it is improperly selected, it may have a negative impact on the performance of the product;
2. even non-reactive ethyl silane is helpful to improve the water resistance of the product.
Application of silane coupling agent on artificial quartz stone
Artificial quartz stone is a sheet composed of more than 90% natural quartz sand and about 10% colorant, unsaturated resin, curing agent, silane coupling agent, etc., made after negative pressure vacuum, high frequency vibration molding, heating or room temperature curing. . The silane coupling agent SCA-R74M (3-methacryloyloxytrimethoxysilane) acts as a coupling agent and plays a vital role in improving the strength of the sheet, the adhesion of the silica sand and the resin.
Usually, the silane coupling agent is added to the unsaturated resin in a ratio of a few thousandths, and the silica sand and other components are added after being uniformly stirred. Since the silane coupling agent SCA-R74M (3-methacryloyloxytrimethoxysilane) will react with the moisture of resin and air, the unsaturated resin that has added silane coupling agent should be used on the same day. Overnight use may have to add silane again. At the same time, due to the large difference in ambient temperature between winter and summer, the formula should be adjusted at the right time, especially for the curing at room temperature.
