Temperature resistant quaternary ammonium type anion exchange resin phase transfer catalyst and preparation method thereof

Abstract

The invention discloses a temperature resistant quaternary ammonium type anion exchange resin phase transfer catalyst and a preparation method thereof, belonging to the synthesis field of anion exchange resin and phase transfer catalyst. The preparation method comprises the following steps: swelling polystyrene alkylated by macroporous chlorine and divinyl benzene copolymer bead body by solvents, adding a certain amount of N-alkyl aminopyridine, stirring and heating, preserving the temperature at 40-100 DEG C, carrying out salifying reaction at the temperature of 40-100 DEG C for 10-30h, filtering after reaction, washing with alcohol and drying to obtain the temperature resistant quaternary ammonium type anion exchange resin phase transfer catalyst, wherein, the amount of substance ratio of micrococcus chlorinus to N-alkyl aminopyridine is 1:1-3, and the amount of substance of micrococcus chlorines is expressed by chlorine element; the solvents used in swelling are as follows: methylene dichloride, tetrahydrofuran, N,N-dimethyl fomamide or n-butyl alcohol; the expressed polystyrene and divinyl benzene co-polymer framework is a repeat unit of the polystyrene and the divinyl benzene; and k, n, and m are respectively 0,1,2,3.

Description

technical field [0001] The invention relates to a temperature-resistant quaternary ammonium type anion exchange resin phase transfer catalyst and a preparation method thereof, belonging to the synthesis field of ion exchange resins and phase transfer catalysts. Background technique [0002] Phase transfer catalysis is widely used in heterogeneous chemical reactions, and quaternary ammonium salts are commonly used phase transfer catalysts. Common quaternary ammonium salt catalysts have poor temperature resistance and are easy to decompose at higher temperatures and lose their catalytic activity; moreover, the quaternary ammonium salt catalysts in the reaction system are difficult to separate and reuse from the reaction system due to their good water and oil solubility. , Even waste water with high organic content will be produced, thus affecting the scope of use of quaternary ammonium salt phase transfer catalysts. [0003] In order to overcome the above shortcomings, as ear...

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Problems solved by technology

Among them, the research on the polymer phase transfer catalyst with polystyrene as the carrier is particularly prominent. In order to improve the temperature resistance of this type of quaternary ammonium salt phase transfer catalyst, the patent No. is JP10137752, JP10053550 Japanese invention patent, EP0776911 European patent, US5864172 The Chinese patents of U.S. Patent and CN1513597, CN1460551, these applications disclose respectively by introducing the hydrocarbyl group of different carbon number between benzene ring and quaternary ammonium carbon atom to improve resin thermal stability and obtain certain effect, its shortcoming is that The reaction time is long, and the immobilized quaternary ammonium salt is prone to Hofman elimination reaction, which makes the active center fall off and the activity is greatly reduced

In synthetic chemistry in 1997, Yu Shanxin and others announced a technology of immobilizing pyridine with a rigid structure onto a polymer resin. The temperature resistance of this type of quaternary ammonium salt resin prepared has been significantly improved, but its catalytic activity Not as high as traditional quaternary ammonium resins

[0004] In 2006, Jiang Fang and others found that the activity of the three-phase phase transfer catalyst with polymer as the skeleton carrier was significantly lower than that of the small molecule quaternary ammonium salt catalyst. In order to improve its catalytic activity, Guo Xikun and others had reduced the crosslinking of the resin skeleton. The method of increasing the degree of cross-linking has achieved certain results, but the reduction of the degree of cross-linking also leads to the reduction of the strength of the resin skeleton.

As early as 1987 on the ACS Symposium Series, Stable Catalysts for Phase Transfer at Elevated Temperatures disclosed a method of increasing the steric hindrance by changing the alkyl group to improve the thermal stability and catalytic activity of the phase transfer catalyst. Zhu Hongying et al. in 2002 The application of chemistry discloses the use of 4-dialkylaminopyridine and small molecular chlorinated alkanes to prepare phase transfer catalysts, showing good thermal stability and catalytic activity. Utilization, and difficult to separate from the reaction system

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