Preparation method of 2-acrylamido-2-methylpropanesulfonic acid

Abstract

The invention relates to the technical field of organic synthesis preparation, in particular to a preparation method of 2-acrylamido-2-methylpropanesulfonic acid, which can improve the purity of the 2-acrylamido-2-methylpropanesulfonic acid finished product, reduce the impurity content, avoid the influence on the molecular weight in the subsequent polymer preparation process, and reduce influenceon the use effect of 2-acrylamido-2-methylpropanesulfonic acid; the method comprises the following steps: S1, preparing a sulfuric acid mixed solution; S2, performing cooling treatment; S3, firstly introducing acrylonitrile into a reaction kettle, then introducing a sulfuric acid mixed solution into the reaction kettle, and finally gradually introducing isobutene into the reaction kettle to carryout a mixed reaction, wherein a sulfuric acid mixed solution is firstly introduced, then acrylonitrile is introduced and isobutene is finally introduced, and continuously carrying out a stirring reaction for 1-2 hours after the addition of the materials is completed, wherein the reaction process needs to be carried out in a helium atmosphere; S4, filtering and separating; S5, preparing a solution;S6, carrying out recrystallization treatment; and S7, performing drying treatment.

Description

technical field [0001] The invention relates to the technical field of organic synthesis preparation, in particular to a preparation method of 2-acrylamido-2-methylpropanesulfonic acid. Background technique [0002] Acrylamido-2-methylpropanesulfonic acid is a white crystal with a melting point of 195°C (decomposition). It is a multifunctional water-soluble anionic monomer, which is easy to self-polymerize or copolymerize with other ethylenic monomers. It is soluble in water , the solution is acidic. Soluble in dimethylformamide, partially soluble in methanol, ethanol, insoluble in acetone. Slightly sour. There are polymerizable vinyl groups and hydrophilic sulfonic acid groups in the molecule of this product, and it can be copolymerized with water-soluble monomers such as acrylonitrile and acrylamide, and water-insoluble monomers such as styrene and vinyl chloride. Its molecular structure has carbon-carbon double bonds, carboxyl and sulfonic acid functional groups. The s...

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Problems solved by technology

[0004] In the production process of existing 2-acrylamido-2-methylpropanesulfonic acid, generally adopt oleum, acrylonitrile and isobutylene as raw material to produce 2-acrylamido-2-methylpropanesulfonic acid, after drying Obtain finished product crystal, although existing 2-acrylamido-2-methylpropanesulfonic acid preparation method is relatively mature, still contain a small amount of impurity in its product, comprise N-tert-butylacrylamide, isobutylene sulfonation product , isobutylene polymer, acrylamide, etc. Although these impurities are trace impurities in the product and the content is not high, they have a relatively large impact on the application of downstream customers, and will affect the molecular weight of polymers made by downstream customers, thus affecting 2-propylene Effect of using amido-2-methylpropanesulfonic acid