The difference between coupling agents and cross-linking agents:
Cross-linking agents generally refer to a class of chemicals that participate in resin cross-linking reactions to connect active functional groups in the resin to create a network structure. The cross-linking agent can mainly improve the viscosity and elasticity of the working fluid. At the same time, it should also have certain temperature and salt resistance according to the geological characteristics of the reservoir. In addition, some additives will be added to improve the overall performance of the working fluid.
Coupling agents generally refer to small molecule chemicals containing 3 or more hydrolyzable carbon functional groups. Using a small amount can improve the durability of organic and inorganic materials. It is famous for its adhesion, reactivity of hydrolyzable groups and fixation of carbon groups on the surface of organic materials. In other words, it can form a bridge between the resin and the interface, increasing the durability of coatings and adhesives. Adhesive strength, low dosage.
The difference between the two is not very big. The coupling agent is a type of substance with two different functional groups. Some of the functional groups in their molecules can react with adsorbed water or hydroxyl groups on the surface of inorganic substances, and some of the functional groups can react with organic molecules to form adhesion or coupling. There is little difference between cross-linking agents and bridging agents. They can both cross-link linear molecules into a network structure.
Cross-linking agents are mainly used in polymer materials, because the molecular structure of polymer materials is like long lines without cross-linking It has low strength, is easy to break, and has no elasticity. The function of the cross-linking agent is to generate chemical bonds between linear molecules, so that the linear molecules are connected to each other to form a network structure, thus improving the strength and elasticity of the rubber. The cross-linking agent used in the process is mainly sulfur, and an accelerator must be added.
The difference between coupling agents and compatibilizers:
In a sense, both are surfactants with different uses.
1. Coupling agents are mainly used between inorganic and organic. The main function is to improve the compatibility between fillers and resin molecular chains. High fillers are used in resins. Dispersion in silane and titanate coupling agents;
2. Compatibilizer is used to improve the compatibility between blended polymers, that is, the compatibility between two different resins in polymer alloys. They are all produced by reactive extrusion of polyolefins grafted with reactive grafts such as maleic anhydride and GMA, and there are also synthetic polar polymers.
Coupling agent effective time:
The environment in which the coupling agent is used, such as humidity, storage time, ink and coating formula and ph value, etc. Most titanates and silanes are weakly alkaline and decompose into alcohols when hydrophilic. Their effect is poor in the humid and rainy seasons in the south, and it takes longer to dry in the north. It is also necessary to check whether the spraying interface is weakly acidic or acidic, which is common. There are three series: KH (silane), A (titanate) and N (azo). They are reactive towards water, alcohol, ether, ammonia, amine and acid and lose coupling ability after reaction. During long-term storage, attention should be paid to avoiding oxygen and frequent spot inspections.
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