Salen catalyst using CN as axial ligand, and preparation method and application thereof

A catalyst and ligand technology, applied in the field of Salen catalyst and its preparation, can solve the problems of selectivity and polycarbonate chain link decline, affecting product performance, etc. the resulting effect of

Inactive Publication Date: 2017-07-25
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
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Problems solved by technology

[0007] Using Cl and Br as the axial ligands of the Salen catalyst is a widely studied catalytic system at present, but when the reaction temperature increases, the regio and stereoselectivity of the polymerization product decrease sharply, and the polymerization reaction is an exothermic process, if The thermal effect during the reaction cannot be diffused immediately, and the local temperature rise will lead to a sharp drop in selectivity and polycarbonate chains, thereby affecting product performance, which is also a major factor limiting the scale-up of the Salen system

Method used

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  • Salen catalyst using CN as axial ligand, and preparation method and application thereof
  • Salen catalyst using CN as axial ligand, and preparation method and application thereof
  • Salen catalyst using CN as axial ligand, and preparation method and application thereof

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Embodiment 1

[0039] A SalenCo (III) CN catalyst, during preparation, at first cyclohexanediamine is split, then 2mol of 3,5-di-tert-butyl salicylaldehyde and 1mol of split cyclohexanediamine are synthesized into salicylaldimine, and then combined with anhydrous acetic acid The cobalt reaction is coupled with the metal center, and finally the SalenCo (II) Oxidation to trivalent and coupled with the axial ligand CN, the specific steps are:

[0040] (1) Splitting of cyclohexanediamine: Fix a 500mL three-neck flask in an oil bath, install a mechanical stirrer, a constant pressure dropping funnel, and a spherical reflux condenser at its three openings, and connect the pipelines After passing the condensed water, add 37.5g L-(+) tartaric acid and 100mL distilled water into the flask, turn on the mechanical stirrer, set the temperature of the oil bath to 70°C, measure 66.6mL of cis-trans cyclohexanediamine and pour it into the constant pressure drop Slowly add it dropwise into the above solutio...

Embodiment 2

[0046] When the catalyst is used for the copolymerization reaction of carbon dioxide and epoxide to prepare polycarbonate, the specific steps are as follows: clean the reactor, vacuumize it, preheat it to 110°C, replace it with carbon dioxide three times, keep the vacuum state, and cool down the reactor to At 25°C, weigh the catalyst and propylene oxide, raise the temperature to the polymerization temperature, inject carbon dioxide to the set pressure, start mechanical stirring, and start timing. After the reaction is over, first turn off the mechanical stirring, lower the temperature to 25°C, open the pressure relief valve to release unreacted carbon dioxide, open the reaction kettle and quickly take it out for further 1 H NMR and GPC analysis of the reaction product tested, sample preparation test. Take out the remaining polymerization product and put it into a small beaker, add a small amount of CH 2 Cl 2 , Stir to dissolve it, then slowly pour it into a beaker containing...

Embodiment 3

[0049] In this example, 0.1mol Salen-Co was added to the reactor (III) CN and 0.1mol cocatalyst PPNCl, 14mL propylene oxide, set the reaction temperature to 50°C, feed 2.0MPa carbon dioxide, start mechanical stirring, and react for 2 hours. Polymerization result: TOF=378.59h -1 , selectivity = 94%, Mn = 27.7 kg / mol, PDI = 1.01.

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Abstract

The invention relates to a Salen catalyst using CN as an axial ligand, and a preparation method and application thereof. The method comprises the following preparation steps of (1) synthesizing Salen H2; (2) performing mixing reaction on the Salen H2 with metal M salt ethyl alcohol solution to synthesize Salen-M; (3) performing mixing reaction on the Salen-M and the metal cyanide solution to synthesize the Salen catalyst using CN as the axial ligand. Compared with the prior art, the method has the advantages that the cyano group with strong electron absorption capability is used as the axial ligand; the catalyst is stable; the deterioration and inactivation cannot easily occur; in a reaction process of catalyzing the copolymerization of carbon dioxide and epoxypropane to synthesize polycarbonate, the inhibition of the generation of cyclic carbonates byproducts is facilitated; the reaction window is widened; under the high-temperature polymerization condition, the activity of the Salen catalyst can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of catalysts, in particular to a Salen catalyst with CN as an axial ligand, a preparation method and application thereof. Background technique [0002] With the strengthening of people's awareness of environmental protection, green and low-carbon has become the main theme of people's life, and it is urgent to solve the problem of environmental pollution. with CO 2 Natural disasters such as global temperature rise, sea level rise, and climate anomalies, mainly caused by greenhouse gases, have brought very serious consequences to the earth's ecology, and even threaten the survival of human beings. At present, the global industrial carbon dioxide emissions are still continues to increase, and the resulting environmental problems are also increasing with the CO in the atmosphere 2 The increase of the content continues to deteriorate, and in the long run, it will seriously threaten the environment on which huma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G64/34
CPCC08G64/34
Inventor 程瑞华李佳佳周宇杰刘柏平
Owner EAST CHINA UNIV OF SCI & TECH
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