The difference between coupling agents and cross-linking agents:
Cross-linking agents generally refer to participating in resin cross-linking reactions to connect active functional groups in the resin to create a network structure a class of chemicals. 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 adhesion of organic and inorganic materials. Hydrolyzable groups The reactivity of the group and the fixability of the carbon group on the surface of organic materials, that is to say, it can form a bridge between the resin and the interface, increase the adhesion of coatings and adhesives, and use a small amount.
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. When not cross-linked, the strength is low, easy to break, and has no elasticity. The role of cross-linking agents It 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 rubber is mainly sulfur, and an accelerator is added.
The difference between coupling agents and compatibilizers:
In a sense, both are surfactants , with different uses.
1. The coupling agent is mainly used between inorganic and organic. Its main function is to improve the compatibility between the filler and the resin molecular chain, and to improve the dispersion of the filler in the resin. Such as silane and titanate coupling agents;
2. Compatibilizer is used to improve the phase between blended polymers, that is, between two different resins in polymer alloys. Capacitive polymers are usually polyolefins produced through reactive extrusion, 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. 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.
