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A kind of controllable depolymerization method of polycaprolactone

A technology of polycaprolactone and depolymerization, which is applied in the direction of organic chemistry, can solve the problems of increased safety risks, and achieve the effects of maintaining negative pressure, high efficiency, and good operational safety

Active Publication Date: 2021-11-09
CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

While using a large amount of diethanolamine depolymerization agent in this method, the pressure of the reaction system is 10 to 30 standard atmospheres; due to the high temperature of the depolymerization reaction, the formed high temperature and high pressure conditions increase the safety risk during the implementation of the method

Method used

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  • A kind of controllable depolymerization method of polycaprolactone
  • A kind of controllable depolymerization method of polycaprolactone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] After mixing 150 g of polycaprolactone polyol (number average molecular weight ≈ 1000) and 15 g of stannous octoate, they were added into a three-necked flask with a magnetic stirring bar. Insert the three-necked flask into the attached figure 1 In the depolymerization reaction device shown, after the system is evacuated, the gas in the system is replaced with nitrogen, and the process is repeated three times. Vacuumize until the air pressure in the system is lower than 3000Pa, start heating to 100°C, and vacuumize to remove water for 30min. Continue vacuuming until the pressure in the system is lower than 500 Pa, then raise the temperature to 210° C., condense and collect the depolymerization product while stirring the reaction for 480 minutes, and the reaction is completed. 108.5 g of liquid fractions were collected, and the content of ε-caprolactone monomer in the liquid was detected by gas chromatography to be 98.9%, and the recovery rate of ε-caprolactone was 76.0...

Embodiment 2

[0047] After mixing 100 g of polycaprolactone polyol (number average molecular weight ≈ 1000) and 5 g of stannous octoate, they were added into a three-necked flask with a magnetic stirring bar. Insert the three-necked flask into the attached figure 1 In the depolymerization reaction device shown, after the system is evacuated, the gas in the system is replaced with nitrogen, and the process is repeated three times. Vacuumize until the air pressure in the system is lower than 3000Pa, start heating to 100°C, and vacuumize to remove water for 30min. Continue vacuuming until the pressure in the system is lower than 500 Pa, then raise the temperature to 220° C., condense and collect the depolymerization product while stirring the reaction for 600 minutes, and the reaction is completed. 76.4 g of liquid fractions were collected, the content of ε-caprolactone monomer in the liquid detected by gas chromatography was 96.8%, and the recovery rate of ε-caprolactone was 78.6%.

Embodiment 3

[0049] After mixing 30 g of polycaprolactone polyol (number average molecular weight ≈ 1000) and 0.9 g of stannous octoate, they were added into a three-neck flask with a magnetic stirring bar. Insert the three-necked flask into the attached figure 1 In the depolymerization reaction device shown, after the system is evacuated, the gas in the system is replaced with nitrogen, and the process is repeated three times. Vacuumize until the air pressure in the system is lower than 3000Pa, start heating to 100°C, and vacuumize to remove water for 30min. Continue vacuuming until the pressure in the system is lower than 500 Pa, then raise the temperature to 230° C., condense and collect the depolymerization product while stirring and reacting for 600 minutes, and the reaction is completed. 18.9 g of liquid fractions were collected, the content of ε-caprolactone monomer in the liquid detected by gas chromatography was 93.7%, and the recovery rate of ε-caprolactone was 62.8%.

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Abstract

The invention provides a controllable depolymerization method of polycaprolactone, which comprises the following steps: under the condition of anhydrous and oxygen-free, polycaprolactone is contacted with a catalyst to carry out depolymerization reaction, while depolymerization is performed under reduced pressure distillation, The depolymerization product is collected by condensation; the catalyst is one or more of tin salt, stannous salt, magnesium salt and titanium salt; the mass of the catalyst accounts for 1-10% of the mass of the polycaprolactone. The invention utilizes the method of vacuuming to continuously steam out the ε-caprolactone monomer produced in the depolymerization and cyclization process in the system, which can promote the movement of the reaction balance to the direction of generating ε-caprolactone and realize the depolymerization of polycaprolactone. Further, the present invention designs to increase the concentration of the catalyst, and the concentration of the catalyst used is more than 10 times that of the conventional ε-caprolactone ring-opening polymerization reaction catalyst, which effectively improves the efficiency of the depolymerization reaction.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a controllable depolymerization method of polycaprolactone. Background technique [0002] Polycaprolactone, also known as polyε-caprolactone, is an important synthetic aliphatic polyester material. The repeating unit of the polycaprolactone molecular chain has 5 non-polar methylene groups (-CH 2 -) and a polar ester group (-COO-), its unique molecular structure endows it with many special properties, including: 1) faster crystallization rate and higher crystallinity; 2) lower glass Transformation temperature (Tg) and melting point, pyrolysis temperature nearly 100 ℃ higher than ordinary polyester; 3) rubbery state at room temperature, elongation at break ≥ 600%; 4) good rheology, viscoelasticity, good Flexibility and processing performance; 5) Outstanding anti-ultraviolet radiation, wear resistance, anti-aging performance, longer degradation half-life than...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D313/04
CPCC07D313/04
Inventor 孙志强张涵庞烜段然龙周延川陈学思
Owner CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI