N-methyl pyrrolidone (NMP) is a polar non-proton transfer solvent, which can be mixed with most organic solvents and easily separated from many organic and inorganic substances. It can be mixed with water in any proportion. Compared with other solvents, it has higher flash point, boiling point and lower solidification point, and has excellent chemical and thermal stability.
Lithium battery < br /> Application of NMP and PVDF in lithium-ion batteries The main organic solvents used in slurry mixing for lithium-ion batteries are N-lithium batteries-methyl pyrrolidone, and the characteristics of N-methyl pyrrolidone have significant effects on lithium-ion batteries, from the process of mixing plates to the characteristics of batteries, especially the cycle of batteries. Life. PVDF has two main uses in lithium batteries. One is to dissolve PVDF in NMP as an adhesive for electrode coating. The repetitive units in the chemical structure of PVDF make it polar and easy to match with NMP which belongs to polar organic solvents.
Another use is to synthesize copolymers from PVDF and other organic materials as one of the electrolyte materials for lithium ion batteries, such as PVDF and HFP (hexafluoropropylene) copolymerization to form PVDF-HFP copolymers with good thermal stability, film formation and chemical resistance. PVDF-based polymer electrolytes have been active in recent years. The trend of development is that N-methyl pyrrolidone can dissolve PVC, PU, PMMA and other coatings < br />. 1. Surface coating
NMP is a non-corrosive and high boiler with excellent solvent performance, chemical and thermal resistance. Therefore, NMP improves the performance of many surface coating systems. In particular, these effects are conducive to the curing of dry coatings at relatively high temperatures. NMP is suitable for the production of highly filled paints. Because it improves the rheological properties and improves the fluidity and coverage of the paint, the paint is more uniform, porous and crack-free, showing greater resistance and higher mechanical strength.
NMP is an excellent solvent for most paint raw materials, such as acrylate, epoxy resin, polyurethane, polyvinyl chloride system, Enamel-based polyamide, water-borne paint and printing ink.
NMP is a very useful solvent for butadiene acrylonitrile polymer (NBR) as the lining of the container. Rubber mixtures have better fluidity and horizontality than those containing ketones.
Vinyl chloride-vinyl acetate-copolymer can be dissolved in the mixed solution of NMP and mononuclear aromatic hydrocarbons. It can be used for film injection. Under the action of the two solvents, the mixed solution has low viscosity and can be used at any time.
Polyisocyanate containing imide group can be dissolved in solvent of NMP system. These solutions can be used for rubber compounds on metal surfaces.
2. Wire coating
In the manufacture of thermosetting insulating coatings, N-methyl pyrrolidone has a good solubility for polycarboxylic acids and their anhydrides, such as trimellitic, phthalic anhydrides, amide polymers and carboxylic groups with high aromatic content.
Therefore, polyisocyanates containing amides are formed in the condensation reaction of NMP mixed solution composed of polycarboxylic anhydride and monomer polyisocyanate. Copper conductors with flow coating of drying oil have excellent mechanical and dielectric properties. From a technical point of view, NMP has advantages in the operation of two functions: as a reaction medium in the manufacturing process, the coating of the latter is used as a viscosity regulator.
The copolyester resin NMP is a suitable solvent for the reaction of diimide and polyol. The solvents thus formed can be dried to form high heat-resistant enamel wires. At the same time, NMP is also used as a solvent for polyamide/polyimide drying oils derived from condensation of aromatic and aliphatic diamines of tricarboxylic acids.
Plastic
NMP is an industrial solvent widely used in natural and synthetic plastics, waxes, resins and paints. It is soluble in polymers such as cellulose derivatives, polyamides, polyimide resins, polyesters, polystyrene, polyacrylonitrile, polyvinyl chloride, polyvinyl pyrrolidone acetate, polyurethane, polycarbonate, polyether and many copolymers.
NMP is mixed with corresponding monomers, conventional organic solvents and water phases. Therefore, the best solvent formulation for a particular application can be found. The example below illustrates the advantages of NMP in solving problems, which can be found in the plastic industry.
Therefore, for example, NMP is widely used in the prefabrication of semi-permeable membranes. Such membranes are used in separation processes, such as ultrafiltration and reverse osmosis. Water purification in the field is as useful as hemodialysis.
In addition, there are also some technical problems arising from linear high polymer fibers, films, tapes and other products. The difficulty lies in the fact that solutions or plastic products can only be kept corrosion-resistant, harmless and non-flammable at normal operating temperatures. NMP is very useful because it is suitable for highly concentrated mixed solutions or for the manufacture of plasticizable compounds from polyamide, polyacrylonitrile, polyvinyl chloride, polystyrene and cellulose triacetate. It can also be applied to the operation of vinyl fluoride homopolymer and foreign molecular polymer at elevated temperature.
Chemical production reagent
NMP has been widely used in large-scale recovery of hydrocarbon solvent purification.
This technology takes advantage of the high solubility of hydrogen carbide in NMP, but in fact the difference is that NMP often exists.