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Cyclic aliphatic polyester preparation method

A cyclic aliphatic and polyester technology is applied in the field of preparation of cyclic aliphatic polyester, which can solve the problems of complex synthesis process and high catalyst cost, achieve high yield, avoid solvent waste and improve efficiency.

Inactive Publication Date: 2012-11-21
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the cost of lactide monomers and N-heterocyclic carbene catalysts used in this polymerization method is relatively high, and the synthesis process is relatively complicated.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Add 1.90 g of potassium 2-bromopropionate and 0.264 g of 18-crown-6 into 50 ml of refluxing 1,2-dichloroethane, and react for 8 hours. Extracted with diethyl ether and water three times, the organic layer was taken and dried overnight with anhydrous magnesium sulfate. After filtration, the solvent in the filtrate was evaporated to obtain a light yellow transparent viscous liquid. Among them, the mass fraction of cyclic polylactic acid is 16.7%.

[0016] The above light yellow viscous liquid was placed in a 50 ml flask, and 1% molar amount of stannous octoate was added. At 100°C, nitrogen gas was introduced first, and then vacuum was pumped, and the operation was repeated 3 times. Then gradually raise the temperature to 150°C under vacuum, and distill under reduced pressure for 15 hours to obtain a pale yellow solid residue, which is cyclic polylactic acid, characterized by NMR and time-of-flight mass spectrometry, and its purity is greater than 99%.

Embodiment 2

[0018] Add 1.76 g of potassium 2-bromoacetate and 0.264 g of 18-crown-6 into 50 ml of refluxing chloroform, and react for 12 hours. Extracted with diethyl ether and water three times, the organic layer was taken and dried overnight with anhydrous magnesium sulfate. After filtration, the solvent in the filtrate was evaporated to obtain a milky white transparent viscous liquid. Among them, the mass fraction of cyclic polyglycolic acid is 33.3%.

[0019] The above light yellow viscous liquid was placed in a 50 ml flask, and 1% molar amount of stannous octoate was added. At 100°C, nitrogen gas was introduced first, and then vacuum was pumped, and the operation was repeated 3 times. Then gradually raise the temperature to 150°C under vacuum, and distill under reduced pressure for 20 hours to obtain a milky white solid residue, which is cyclic polyglycolic acid, characterized by NMR and time-of-flight mass spectrometry, and its purity is greater than 95.5%.

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Abstract

A cyclic aliphatic polyester preparation method belongs to the chemical field of high polymer syntheses. The method is characterized by comprising the following steps: placing 2-bromine carboxylate in an organic solvent, adding a phase-transfer catalyst of 0-30 percent of the 2-bromine carboxylate by molar weight so as to react for 3-48 hours, extracting the reaction mixture with ethyl ether and water, taking a diethyl ether layer to be dried with anhydrous magnesium sulfate, and removing the solvent through evaporation after filtering; and then, adding 0-10 percent of stannous octoate by molar weight in the production obtained from the polymerization process, and distilling the mixture for more than 15 hours under a pressure reduction condition when the temperature is gradually increased to 150-230 DEG C. The method has the benefits that high-yield and high-purity cyclic polylactic acid and cyclic polyglycolic acid can be obtained under a mild reaction condition through using a lower-cost monomer. The cyclic aliphatic polyester, as a cyclic monomer, can be applied to the field of active controllable polymerization field so as to prepare the high molecular weight aliphatic polyester, and has potential economic benefits.

Description

technical field [0001] The invention belongs to the technical field of polymer synthesis, and in particular relates to a preparation method of cycloaliphatic polyester. Background technique [0002] Cyclic polymers are a type of polymers with special structures. Because there are no end groups bound, the structural units on the molecular chains are equivalent. Compared with polymers with other topological structures, they have special physical and chemical properties. Therefore, cyclic polymers have always been a subject of concern for researchers. Cyclic polymers are mainly obtained through intramolecular ring closure reactions in highly dilute solutions. According to the ring-chain equilibrium theory, the reaction in solution at a concentration of about 2 w / v % gave the highest yield of cyclic polymers. Therefore, the efficiency of preparing cyclic polymers by ring-closing technology is usually low, and it is difficult to avoid the residue of linear polymers. [0003] I...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/79C08G63/90C08G63/00
Inventor 郑玉斌方园园
Owner DALIAN UNIV OF TECH
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