Aliphatic polycarbonate washing coagulation devolatilization method and specific device thereof

Abstract

The invention discloses an aliphatic polycarbonate washing coagulation devolatilization method and a specific device thereof. The device according to the invention comprises: a polymerization kettle (1), a flash glue solution vessel, a coagulation system composed of more than one washing coagulation kettles (3), a solid-liquid separation system (4), a polymer drying system (5), a gear pump (6) and a connecting pipeline, wherein the polymerization kettle is provided with a product outlet at the lower part thereof and a gas outlet at the upper part thereof; the flash glue solution vessel is provided with an inlet and a gas outlet at the upper part thereof and a liquid outlet at the lower part thereof; and the washing coagulation kettle is provided with a washing coagulant inlet at the lower part thereof, a liquid inlet and a liquid outlet at the middle part thereof and a gas outlet at the upper part thereof. The method according to the invention has the advantages of: simple production technology, good suitability for automated control, continuous washing coagulation devolatilization; sufficient use of materials and energies, no gas-phase emptying in the process owing to the use of a closed vessel with pressure, very few solid-liquid wastes, complete ash removal and devolatilization of products, meeting the use demands in related fields, low industrial production cost and green chemistry standard-reaching industrialization process.

Description

technical field [0001] The invention relates to a method for washing, coagulation and devolatilization of aliphatic polycarbonate and a special device thereof. Background technique [0002] Carbon dioxide is the main gas responsible for the greenhouse effect and one of the most abundant sources of carbon on Earth. The chemical fixation of carbon dioxide is an important research field of green chemistry. Among them, a main direction of utilizing carbon dioxide is to prepare polycarbonate by copolymerizing it with alkylene oxide under the action of a catalyst. Polycarbonate can be photodegraded or biodegraded, and also has excellent oxygen and water barrier properties, and can be used as degradable non-polluting materials, disposable medical and food packaging materials, adhesives and composite materials. [0003] Since Japan Inous discovered in 1969 that carbon dioxide can be fixed into a fully biodegradable polymer, there have been many patent reports on the preparation of...

AI Technical Summary

Problems solved by technology

The reaction of synthesizing aliphatic polycarbonate resin with carbon dioxide and epoxide is bulk polymerization. At the end of the reaction, 40-70% of epoxide in the polymer system has not reacted. If this part of raw materials is not recovered, The cost of the product is greatly increased; on the other hand, the residual volatile matter in the polymer is harmful to the atmosphere and the human body, and affects the performance of the material

Taixing Jinlong Green Chemical Co., Ltd. and Guangzhou Chemical Company of the Chinese Academy of Sciences (CN200410044938.X) proposed a refining process for aliphatic polycarbonate resin, by adding a chelating agent and an adsorbent to the polymer glue, and treating it at a certain temperature for a period of time. Filter and remove the solvent after a period of time to remove the metal complex catalyst in the aliphatic polycarbonate resin. Although the removal of the catalyst residue is relatively complete, the process is complicated and does not mention the removal of volatile matter. Industrialization High difficulty

Mengxi High-tech Group and Changchun Institute of Applied Chemicals (CN200610077582.9) proposed a method for desolventizing aliphatic polypropylene carbonate. The polymer of propylene carbonate is placed in a stirred tank container, and the desolvent is added to carry out multiple desolvation under stirring, so as to realize the extraction and washing of catalyst residues, oligomers and PC, etc., and then the material After separation and drying, the aliphatic polypropylene carbonate polymer with residual ash less than 1% is obtained. Although the process is simple, it adopts static sedimentation and gap separation, which has low efficiency and is difficult to adopt in large-scale industrial production.

The aliphatic polycarbonate resin additive-free devolatilization device proposed by Henan Tianguan Enterprise Group and Sun Yat-sen University (CN 200620031757.8) uses a container with stirring and heating to primary devolatilize the polymer glue, and then pump it into the discharge through a high-viscosity pump. The gas extruder further devolatilizes to effectively remove the volatile components in the aliphatic polycarbonate resin produced by the polymerization of carbon dioxide and epoxide. The process technology is difficult, the equipment requirements are high, and the investment is large. There are successful precedents in the production of styrene-butadiene resin, but the catalyst residue and oligomers in the polymer cannot be partially removed, and it is difficult to meet the industrial production of aliphatic polycarbonate

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