Production of fatty poly-ester carbonate polyhydric alcohol

Abstract

Production of fatty polycarbonate polyol is carried out by taking carbon dioxide / epoxide as raw materials, putting catalyst, epoxide and molecular-weight regulator into cyclic reactor and copolymerization reacting under action of the catalyst in cyclic reactor at 0.1-8MPa and 40-150degree for 0.5-48hrs. The main apparatus consists of cyclic reactor, condenser, vapor / liquid separator, high-pressure carbon dioxide buffer tank, carbon dioxide compressor and liquid cyclic pump, the said cyclic reactor is arranged with single draft tube and multiple draft tubes. It costs low and is efficient.

Description

technical field [0001] The invention relates to a production process of polyols, more specifically to a production process of aliphatic polycarbonate polyols, and belongs to the technical field of carbon dioxide copolymer production. Background technique [0002] Aliphatic polycarbonate polyol is a new type of polyol resin. Its molecular main chain contains aliphatic alkylene and carbonate units, which is quite different from traditional polycarbonate materials. It is different from aliphatic polyester polyol and polyol. Ether polyols are similar, and their properties are between polyester and polyether polyols, such as lower glass transition temperature (glass transition), better room temperature flexibility, etc.; the polyurethane material prepared from this polyol has Many unique properties, such as aliphatic polycarbonate polyurethane elastomers have excellent hydrolysis resistance, low temperature flexibility of polyether polyurethane elastomers and high mechanical stre...

AI Technical Summary

Problems solved by technology

The process is a three-phase reaction of vapor, liquid and solid. Due to the use of a tank reactor, the mixing effect of the system is poor during industrial scale-up, and reaction dead ends are prone to occur, resulting in poor product quality stability.

In addition, due to the high pressure of the carbon dioxide / epoxide copolymerization reaction, during industrial scale-up, as the volume of the reactor increases, the energy consumption of mechanical stirring and investment costs will increase sharply, resulting in an increase in production costs

At the same time, for high-pressure reactions, the utilization rate of the tank reactor is low, and its feeding capacity is generally only 1 / 2-2 / 3 of the effective volume of the reactor.

Finally, the production cost of aliphatic polycarbonate polyol is high, and the market competitiveness of the product is low, which affects the large-scale industrial production and application of the resin

[0005] Loop reactors can be used for carbon dioxide / epoxide copolymerization to prepare aliphatic polycarbonate polyols, however, for some low boiling point epoxides, such as ethylene oxide, propylene oxide, etc., under the conditions of polymerization reaction temperature, their The saturated vapor pressure is high, and the content of epoxide in the gas phase is relatively large. Before entering the carbon dioxide compressor, this part of propylene oxide needs to be separated. For large-scale industrial devices, the separation requires a large cooling capacity and high energy consumption.

In addition, for industrial production equipment, due to the high pressure, the amount of gas required to drive the liquid circulation by simply relying on gas flow is large, the energy consumption of the compressor is large, and the production cost increases

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