Polylactic acid polymerization reaction device and system

Abstract

The invention relates to the technical field of polylactic acid preparation. The invention discloses a polylactic acid polymerization reaction device and system. The polylactic acid polymerization reaction device comprises a polymerization reactor (10) and a stirring assembly (20) arranged in a flow channel of the polymerization reactor (10), the stirring assembly (20) comprises an electromagneticwinding mechanism and a magnetic induction piece (21); the electromagnetic winding mechanism is arranged around the inner wall of the polymerization reactor (10); the electromagnetic winding mechanism is arranged around the magnetic induction piece (21), and a gap is formed between the electromagnetic winding mechanism and the magnetic induction piece (21), so that the magnetic induction piece (21) and the electromagnetic winding mechanism can generate electromagnetic induction, the magnetic induction piece (21) rotates around the axis of the magnetic induction piece (21), and a threaded groove is formed in the magnetic induction piece (21). According to the polylactic acid polymerization reaction device provided by the invention, the polymerization reaction effect can be improved, so that the conversion rate of a product is improved.

Description

technical field [0001] The invention relates to the technical field of polylactic acid preparation, in particular to a polylactic acid polymerization reaction device and system. Background technique [0002] Conventional polylactic acid polymerization reaction devices generally use thin-film reactors. The inside of the thin-film reactor is covered with special-shaped parts. When the polymerization melt moves from bottom to top, laminar flow is formed to achieve a certain flat push effect. This polymerization method realizes continuous Polymerization, but this kind of device has high melt viscosity, slow conveying speed, low production efficiency; uneven dispersion of additives and melt, low product conversion rate; at the same time, part of the melt is close to the surface of the container during the laminar flow process There is a phenomenon of residence, and there is a large difference in the reaction time of the materials, some of which are incomplete, and some of which a...

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Problems solved by technology

[0002] Conventional polylactic acid polymerization reaction devices generally use thin-film reactors. The inside of the thin-film reactor is covered with special-shaped parts. When the polymerization melt moves from bottom to top, laminar flow is formed to achieve a certain flat push effect. This polymerization method realizes continuous Polymerization, but this kind of device has high melt viscosity, slow conveying speed, low production efficiency; uneven dispersion of additives and melt, low product conversion rate; at the same time, part of the melt is close to the surface of the container during the laminar flow process There is a phenomenon of residence, and there is a large difference in the reaction time of the materials. Some of the reactions are incomplete, and some of them are degraded if the residence time is too long, which eventually leads to a wide molecular weight distribution of the melt and affects product quality.

[0003] On the one hand, a utility model application with application number 03228796.8 discloses a device for preparing polylactic acid by direct polycondensation of lactic acid, and a utility model application with application number 03255460.5 discloses a polymerization reaction device for direct polycondensation of lactic acid to prepare polylactic acid The utility model application of 201220058753.4 discloses the polycondensation preparation system of polylactic acid. The above-mentioned patented reactor is mainly composed of three-necked flasks, condenser tubes and other glass instruments, which are only used for laboratory research and cannot meet the practical application of industrialization.

[0004] On the other hand, some improved polylactic acid polymerization reaction devices currently on the market mostly use vertical and tank-type agitation to drive the polymerization reaction between the melt and the additives. The reaction temperature and time are inconsistent, resulting in a wide molecular weight distribution of polylactic acid chips. At the same time, there is no circulation device in the polymerization process, and the reaction between the melt and the additives is insufficient, which affects the product conversion rate and leads to high production costs.

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