pH-responsive amphoteric surfactant n-lauryl-(α-alkyl)-β-aminopropionic acid and preparation method and uses thereof

Patent metadata

Field	Value
Publication number	US-10781165-B2
Application number	US-201916443898-A
Country	US
Kind code	B2
Filing date	Jun 18, 2019
Priority date	Jun 22, 2018
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

Disclosed are a pH-responsive amphoteric surfactant N-lauryl-(α-alkyl)-β-aminopropionic acid and a preparation method and uses thereof. An alkylamine and a solvent are added to a three-necked flask, stirred for complete dissolution, slowly dropwise added with methyl α-alkyl-acrylate and reacted at room temperature after the ice-water bath is removed. The reaction mixture is refluxed in water bath and evaporated under rotation to remove the solvent and the residual methyl α-alkyl-acrylate to give N-lauryl-(α-alkyl)-β-aminopropionic acid. Then N-lauryl-(α-alkyl)-β-aminopropionic acid and water are added to a three-necked flask, slowly dropwise added with a sodium hydroxide solution and reacted in water bath to give a crude product, which is filtered and dried to give a purified surfactant sodium N-lauryl-(α-alkyl)-β-aminopropionate. This surfactant is suitable for the foamed acid system and its performance can be switched by adjusting pH due to pH sensitivity.

First claim

What is claimed is:

1. A method for preparing a pH-responsive amphoteric surfactant N-lauryl-(α-alkyl)-β-aminopropionic acid, comprising:
(1) adding 40-60 parts by weight of an alkylamine and 20-100 parts by weight of a solvent to a three-necked flask and stirring until they are completely dissolved; placing the three-necked flask in an ice water bath and slowly dropwise adding 25-30 parts by weight of methyl α-alkyl-acrylate to the three-necked flask under stirring; removing the ice water bath and reacting the reaction mixture at room temperature for 4-8 h and then at 70-90° C. in a water bath under reflux for 3-6 h; transferring the reaction mixture to a rotary evaporator to remove the solvent and the residual methyl α-alkyl-acrylate so as to produce N-lauryl-(α-alkyl)-β-aminopropionic acid; and
(2) adding the N-lauryl-(α-alkyl)-β-aminopropionic acid prepared in step (1) and 50-150 parts by weight of water to a three-necked flask; preparing 10-15 parts by weight of sodium hydroxide into a sodium hydroxide solution with a mass fraction of 10%-20%; heating a water bath to 60-80° C. and slowly dropwise adding the sodium hydroxide solution to the three-necked flask to fully saponify the N-lauryl-(α-alkyl)-β-aminopropionic acid; reacting the reaction mixture at 60-70° C. in the water bath for 2-10 h and then at 80-90° C. in the water bath for 2-5 h to produce a crude product; drying the crude product to remove water; dissolving the dried crude product with ethanol followed by filtration to remove the sodium hydroxide while the solution of the dried crude product in ethanol is hot; and drying to produce the amphoteric surfactant sodium N-lauryl-(α-alkyl)-β-aminopropionate.

2. The method of claim 1 , wherein the alkylamine is selected from the group consisting of dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

3. The method of claim 1 , wherein the solvent is selected from the group consisting of methanol, ethanol and isopropanol.

4. The method of claim 1 , wherein the methyl α-alkyl-acrylate has the following structural formula:

wherein R 2 is an alkyl having 1-3 carbon atoms.

Assignees

• Shaanxi Univ Of Science & Technology

Inventors

• Lai Xiaojuan
• Dang Zhiqiang
• Wang Lei
• Ma Shaoyun
• Li Xianwen
• Tian Wei
• Feng Xingen
• Zhang Yinyin
• Yang Xu

Classifications

• C07C227/06 Primary

  by addition or substitution reactions, without increasing the number of carbon atoms in the carbon skeleton of the acid · CPC title

• C07C227/40

  Separation; Purification · CPC title

• C07C229/12

  to carbon atoms of acyclic carbon skeletons · CPC title

• C07C227/18 Primary

  by reactions involving amino or carboxyl groups, e.g. hydrolysis of esters or amides, by formation of halides, salts or esters · CPC title

• C09K8/74

  combined with additives added for specific purposes · CPC title