Preparation process of lactide

A preparation process and lactide technology, applied in the direction of organic chemistry and the like, can solve the problems of high requirements on reaction conditions, low purity of lactide, difficult control of the production process, etc. simple effect

Inactive Publication Date: 2007-04-25
RUGAO FIBERGLASS FACTORY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example: CN1594313A, CN1583740A and CN1488628A all have records, at present, the reaction product containing lactide is obtained by the vacuum distillation method more, and the reaction product is purified 2 to 3 times to obtain lactide. The control is relatively strict, and the purity of the obtained lactide is not very high, the yield of lactide is 60-80%, and the process has been carried out under vacuum, which requires high reaction conditions, and the production process is not easy to control

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Mix 1000kg of L-lactic acid and 10kg of strontium and aluminum composite catalyst system catalyst and pass it into the reactor for dehydration reaction. The reaction conditions in the reactor are controlled at: temperature 150°C, vacuum degree 8000Pa, reaction for 5h, and 700KG lactic acid oligomerization can be obtained Put 700kg of the prepared lactic acid oligomer in a 1000L reaction vessel, and heat it to 150°C under normal pressure; pass nitrogen gas at 200°C into the reactor, and use high-temperature inert gas to take out the vaporized lactide , the mixed gas was cooled to 80° C. and collected, and the collected mixture was purified by solution to obtain 680 kg of lactide, and the lactide yield was 97%.

Embodiment 2

[0016] Mix 1000kg of L-lactic acid and 10kg of strontium and aluminum composite catalyst system catalyst and pass it into the reactor for dehydration reaction. The reaction conditions in the reactor are controlled at: temperature 180°C, vacuum degree 5000Pa, reaction for 4.5h, and 700KG lactic acid low polymer, place 700kg of the prepared lactic acid oligomer in a 1000L reaction vessel, and heat it to 250°C under normal pressure; pass nitrogen gas at 500°C into the reactor, and use high-temperature inert gas to strip the vaporized lactide The mixed gas was cooled to 150° C. and collected. After the collected mixture was purified by solution, 680 kg of lactide was obtained, and the yield of lactide was 97%.

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PUM

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Abstract

The invention discloses a preparing method of lactide in the macromolecular material preparing domain, which comprises the following steps: a. adopting L-lactic acid as raw material to obtain the low-molecular polymer of lactic acid; b. placing the low-molecular polymer of lactic acid in the reactor to react; controlling the reacting condition under normal pressure; heating to 150-250 deg.c; c. aerating inert gas into reactor at 200-500 deg.c; carrying the reacting product out of reactor; cooling to 80-150 deg.c; collecting; purifying extracted compound to obtain the product.

Description

technical field [0001] The invention discloses a method for preparing lactide, which belongs to the field of polymer material manufacturing. Background technique [0002] As the requirements for environmental protection are getting higher and higher, an upsurge of green environmental protection materials has been set off. Because polylactic acid is a synthetic polymer compound that can be completely biodegraded, and lactide is a necessary unit for the preparation of polylactic acid in two steps. body. Therefore, many companies and scientific research institutions at home and abroad have also conducted in-depth research on the preparation of lactide, and applied for related patents. For example: CN1594313A, CN1583740A and CN1488628A all have records, at present, the reaction product containing lactide is obtained by the vacuum distillation method more, and the reaction product is purified 2 to 3 times to obtain lactide. The control is relatively strict, and the purity of th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D319/12
Inventor 顾泽波阮刘文沈晓蔚彭春阳
Owner RUGAO FIBERGLASS FACTORY
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