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Method for preparing polycarbonate by circulating loop type gas-liquid contact process

A polycarbonate, gas-liquid contact technology, which is applied in the field of preparing polycarbonate by the polymerization of alkylene oxide and carbon dioxide, can solve the problems of high energy consumption, poor gas-liquid mass transfer effect, and difficulty in separating polycarbonate, etc. The effect of strengthening gas-liquid mass transfer, improving reaction efficiency, and improving industrial application value

Inactive Publication Date: 2020-07-24
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Chinese patent application numbers CN89100701.6 and CN 91109459.8 disclose a bimetallic catalyst system supported by polymers with anion coordination, and can also obtain 10 4 Catalytic efficiency in grams of polymer per mole of catalyst, but the support is difficult to separate from the resulting polycarbonate
In these processes, due to the poor gas-liquid mass transfer effect, carbon dioxide depends on dissolving in the reaction liquid to participate in the reaction, which greatly limits the reaction speed and also leads to a wide molecular weight distribution, especially in the later stage of the reaction. The reaction process has low efficiency and high energy consumption. Insufficient quality

Method used

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  • Method for preparing polycarbonate by circulating loop type gas-liquid contact process
  • Method for preparing polycarbonate by circulating loop type gas-liquid contact process
  • Method for preparing polycarbonate by circulating loop type gas-liquid contact process

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Experimental program
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Effect test

Embodiment 1

[0025] Embodiment 1: In the circulation loop reactor that effective volume is 10L, add initial recirculation material, material composition is: 0.27 millimolar tetradentate Schiff base cobalt complex (containing quaternary ammonium salt group is in the 5th position of benzene ring; X , Y are both 2,4-dinitrophenol oxyanions; R 1 =R 2 = H; R 3 is tert-butyl; R 4 , R 5 is methyl; R 6 is n-butyl; n is 2; Z is nitrogen), 0.5kg initiator, the initiator is methanol. After the cycle is started, the initial material is heated to 120°C through a heat exchanger, and carbon dioxide is introduced to 5.5MPa. Continuously add 3.2 kg of propylene oxide within 6 hours (the molar ratio of catalyst to alkylene oxide is 1:200000), supplement carbon dioxide to keep the reaction going, and maintain the system pressure at 5.5 MPa. After the feeding was finished, the reaction was continued for 60 minutes, the carbon dioxide was no longer consumed, and the reaction ended. The reaction material...

Embodiment 2

[0026]Embodiment 2: In the circulation loop reactor that effective volume is 10L, add initial recycle material, material composition is: 55 millimolar tetradentate Schiff base cobalt complex (containing quaternary ammonium salt group is in benzene ring 3; X , Y are both 2,4-dinitrophenol oxyanions; R 1 =R 2 = H; R 3 is tert-butyl; R 4 , R 5 is methyl; R 6 is n-butyl; n is 2; Z is nitrogen), 0.5kg initiator, and the initiator is propylene glycol. After the cycle is started, the initial material is heated to 20°C through a heat exchanger, and carbon dioxide is introduced to 0.1MPa. Continuously add 3.2 kg of propylene oxide within 12 hours (the molar ratio of catalyst to alkylene oxide is 1:1000), supplement carbon dioxide to keep the reaction going, and maintain the system pressure at 0.1 MPa. After the feeding was finished, the reaction was continued for 60 minutes, the carbon dioxide was no longer consumed, and the reaction ended. The reaction material was transferred ...

Embodiment 3

[0027] Embodiment 3: In the circulating loop reactor that effective volume is 10L, add initial recirculation material, material composition is: 6 millimolar tetradentate Schiff base cobalt complexes (containing quaternary ammonium salt group in benzene ring 3 and 5 position; X and Y are both 2,4-dinitrophenol oxyanions; R 1 =R 2 = H; R 4 , R 5 is methyl; R 6 is n-butyl; n is 2; Z is nitrogen), 0.5kg initiator, the initiator is polyglycerol ether PGY-400 with a molecular weight of 400. After the cycle is started, the initial material is heated to 60°C through a heat exchanger, and carbon dioxide is introduced to 2.0MPa. Continuously add 3.5 kg of propylene oxide within 6 hours (the molar ratio of catalyst to alkylene oxide is 1:10000), supplement carbon dioxide to keep the reaction going, and maintain the system pressure at 2.0 MPa. After the feeding was finished, the reaction was continued for 45 minutes, the carbon dioxide was no longer consumed, and the reaction ended. ...

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Abstract

The invention belongs to the technical field of polycarbonate preparation, and relates to a method for preparing polycarbonate by a circulating loop type gas-liquid contact process. A functionalized tetradentate Schiff base metal complex is used as a bifunctional catalyst through a circulation loop gas-liquid contact process, and carbon dioxide and alkylene oxide are used as raw materials to carryout polymerization reaction under the conditions that the CO2 pressure is 0.1-5.5 MPa and the reaction temperature is 20-120 DEG C so as to prepare polycarbonate. According to the method, the defectthat the reaction rate is sharply reduced after the epoxyalkane conversion rate reaches a certain degree in the prior art is overcome, and product synthesis under low carbon dioxide pressure is realized. The method has the advantages that the efficiency of preparing polycarbonate through polymerization of carbon dioxide and alkylene oxide is improved and the method has industrial application value.

Description

technical field [0001] The invention belongs to the technical field of polycarbonate preparation, and relates to a method for preparing polycarbonate by a cycle-type gas-liquid contact process, which is a method for preparing polycarbonate by polymerization reaction of alkylene oxide and carbon dioxide. Background technique [0002] carbon dioxide (CO 2 ) As an important carbon source on the earth, it can be converted into carbohydrates through photosynthesis and release oxygen at the same time, which is one of the most important reactions to maintain the ecological cycle. However, in human daily life and industrial production, CO 2 Excessive emissions of the 2 become the main gas that causes the greenhouse effect. Therefore, CO 2 The emission reduction and chemical or physical fixation of carbon dioxide have become one of the most concerned strategic research topics worldwide. Under the action of a catalyst, carbon dioxide can be polymerized with alkylene oxide to prep...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G64/34
CPCC08G64/34
Inventor 任伟民吕小兵李明燃
Owner DALIAN UNIV OF TECH