CN107868076A - The preparation of low impurity content glycolide - Google Patents
The preparation of low impurity content glycolide Download PDFInfo
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- CN107868076A CN107868076A CN201610852271.9A CN201610852271A CN107868076A CN 107868076 A CN107868076 A CN 107868076A CN 201610852271 A CN201610852271 A CN 201610852271A CN 107868076 A CN107868076 A CN 107868076A
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- glycolide
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- polycondensation
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- acid oligomer
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D319/10—1,4-Dioxanes; Hydrogenated 1,4-dioxanes
- C07D319/12—1,4-Dioxanes; Hydrogenated 1,4-dioxanes not condensed with other rings
Abstract
The preparation of low impurity content glycolide.The present invention relates to a kind of preparation method of glycolide, generation is mainly solved the problems, such as to prepare during glycolide more than the ring-type impurity of hexatomic ring, by using the preparation method of glycolide, including glycolic polycondensation is obtained into the condensation polymerization step of glycolic acid oligomer and glycolic acid oligomer progress depolymerization is obtained into the depolymehzation step of glycolide；Wherein, the depolymehzation step specifically includes：At least one polyether solvent is added into reaction system, glycolic acid oligomer and solvent is set to be formed homogeneously, raising system reaction temperature is to 230 270 DEG C, vacuum is improved to 0.1 5KPa simultaneously, the glycolic acid oligomer for obtaining polycondensation is decomposed, and is evaporated under reduced pressure, is obtained the technical scheme of glycolide, preferably solve the problem, can be used in the industrial production of glycolide.
Description
Technical field
The present invention relates to a kind of preparation method of glycolide..
Background technology
Polyglycolic acid (PGA), it is a kind of biodegradable linear aliphatic polyesters, because can degrade in vivo
Into the small molecule that can be absorbed by the body, it is widely used as the medical high score such as operation suture thread, bone material and medicine controlled release carrier
Sub- material.Meanwhile the performance such as PGA heat resistance, barrier, mechanical strength protrudes, thus the replacement using it as resins for universal use
During product and the new application such as material with gas-barrier are also progressively developed.
The preparation of polyglycolic acid typically passes through two kinds of routes：One kind is direct as raw materials melt polycondensation one-step method using glycolic
Polyglycolic acid is prepared, molecular weight prepared by the method is not high.Although molecular weight can be improved by solid phase polycondensation, but still it is difficult to
Meet the requirement of medical material.Another method is to prepare glycolic acid oligomer by raw material of glycolic, then depolymerized oligomer
Glycolide is prepared, glycolide prepares polyglycolic acid by ring-opening polymerisation.This is the common method for preparing HMW PGA.
Glycolide contains plurality of impurities made from depolymerization, except what is be distilled out of under the conditions of high-temperature pressure-reduction with glycolide
Outside the oligomer of glycolic and its small-molecular-weight, also glycolic polymerize the ring-type more than hexatomic ring of generation under the high temperature conditions
Polyester (hereinafter referred to as ring-type impurity).The feature peak-to-peak signal of its nucleus magnetic hydrogen spectrum is respectively：1H-NMR(DMSO-d6,600M,
ppm)：4.825(s).We can calculate that the impurities phase is handed over for second using the integral area for calculating nuclear magnetic signal peak to detect
The content of ester.
The oligomer of glycolic is easy to wash removing, big ring-type with alcohols solvent due to containing carboxyl and hydroxyl in molecule
Polyester is difficult then to be removed in subtractive process.Such polymer is compared to glycolide, it more difficult to degraded and ring-opening polymerisation occurs, therefore
It can remain in the polymer and influence its use as medical material.Therefore need to find a kind of method to reduce the accessory substance
Content.
U.S. patent 2668162 discloses a kind of preparation method of glycolide, passes through melt polycondensation at 170-185 DEG C first
Prepare glycolic acid oligomer, glycolic acid oligomer be then broken into powder, and under a high vacuum 1.6-2.0kPa in 270-
285 DEG C of heating, collect steam of the gained containing glycolide.The yield highest of thick glycolide can reach 93%, the thick second of gained
Lactide is further purified by solvent washing and multiple solvent recrystallization.Method according to the patent has carried out experiment and ground
Study carefully, although as a result showing that yield is higher, acid content is higher in the glycolide of gained, and impurity content is higher.
U.S. patent 4727163 discloses a kind of method, is copolymerized using the polyethers with good thermal stability, in polycondensation
Stage is added in reaction system, and glycolic also carries out block copolymerization with polyethers and obtain block copolymer, most while homopolymerization
Block copolymer is heated afterwards carries out depolymerization, yield 67%.Method according to the patent has carried out the preparation of glycolide.But by
The yield for the glycolide that this method obtains is relatively low.Tracing it to its cause may be due to glycolic acid oligomer chain for the generation of glycolide
Hold back and sting to be formed, block copolymerization, which have impact on back, stings reaction, so as to influence yield.
Numerous patents US5830991, US6891048B2 of Wu Yu companies, US691639B2, CN1496359A,
CN1501923A, addition high boiling point polar organic solvent and solubilizer can be used into glycolic acid oligomer by mentioning, but be solved
Glycolide can steam together with high boiling organic solvent when poly-, and the refined needs of glycolide are by supercharging liquid separation, multistep washing
And the flow dried, it is complex.
The content of the invention
The technical problems to be solved by the invention are that the ring-type more than hexatomic ring can be produced when prior art prepares glycolide
A kind of the problem of impurity, there is provided production method of low impurity content glycolide.It is using glycolic as raw material, passes through normal pressure first
Glycolic acid oligomer is prepared with decompression segmentation polycondensation, then the high temperature depolymerization oligomer prepares glycolide again.Solved by controlling
Poly- reaction condition, the glycolide low more than the ring-type impurity content of hexatomic ring can be prepared.
In order to solve the above technical problems, the present invention uses following technical scheme：A kind of preparation side of low acid content glycolide
Method, including glycolic polycondensation is obtained into the condensation polymerization step of glycolic acid oligomer and glycolic acid oligomer progress depolymerization is obtained into second friendship
The depolymehzation step of ester；Wherein, the depolymehzation step specifically includes：At least one polyether solvent is added into reaction system, is made
Glycolic acid oligomer and solvent are formed homogeneously, improve system reaction temperature to 230-270 DEG C, while improve vacuum to 0.5-
3KPa, the glycolic acid oligomer that polycondensation obtains is decomposed, be evaporated under reduced pressure, obtain glycolide.
In above-mentioned technical proposal, the preparation method of the low acid content glycolide, following steps are preferably included：
(1) polycondensation：A) normal pressure polycondensation, after ethanol acid crystal and catalyst are mixed, reaction temperature is kept 110~220
DEG C, polycondensation reaction is carried out, obtains polyglycolic acid；B) polycondensation is depressurized, after step a, keeps system temperature, while it is true to improve system
Reciprocal of duty cycle continues polycondensation reaction or ester exchange reaction, until no water steams to 0.1-5KPa；C) polycondensation is strengthened, in step
After rapid b, system temperature and vacuum is kept to continue to react 0.5-10 hours.
(2) depolymerization, after step (1), at least one polyether solvent is added into reaction system, makes glycolic acid oligomer
Formed homogeneously with solvent, improve system reaction temperature to 230-270 DEG C, while improve vacuum to 0.5-3KPa, obtain polycondensation
To polyglycolic acid decompose, be evaporated under reduced pressure out glycolide and polyether solvent, product glycolide can be obtained after filtering.
In above-mentioned technical proposal, depolymerization catalyst is preferably the halide of tin or the organic acid compound of tin, or is antimony
Oxide, halide, the organic acid compound of antimony of antimony, or for the oxide of zinc, the halide of zinc, the organic compound of zinc
The complex of thing or zinc, the either complex or rare earth metal complex of organo-aluminum compound or aluminium, or be above two
Or two or more mixed catalysts, the dosage of catalyst are the 0.001-10wt% of glycolic dosage；When strengthening polycondensation reaction
Between in 0.5-10 hours.
The solvent added in above-mentioned technical proposal, during step (2) Solution Depolymerization is the polyethers chemical combination of low molecule amount
Thing, number-average molecular weight are preferably not less than 300 and not higher than 2000；It is liquid or solid under the solvent normal temperature, in de-polymerization temperature
Down solvent can be used as liquid；The amount of the solvent added during depolymerization is the 10-500wt% of glycolic acid oligomer amount, is preferably
100-200%；The molecular structure of the polyether oligomers is R2O(-R1-O-)qR3, wherein R1For C1~C4Alkylidene in one
Kind, more preferably-CH2- or-CH2CH2- in one kind；R2For H or C1~C4Alkyl in one kind, further it is excellent
Elect-H ,-CH as3、-CH2CH3In one kind；R3For H or middle C1~C4Alkyl in one kind, more preferably-H ,-
CH3、-CH2CH3At least one of；0<q<20；Depolymerization reaction temperature is preferably 230-270 DEG C；The vacuum of depolymerization reaction is excellent
Elect 0.5-5KPa, more preferably 1-5KPa as；The time of depolymerization reaction is preferably 1-10 hours.
The advantage of the invention is that：, can by controlling polycondensation reaction condition and depolymerization reaction condition when preparing glycolide
To prepare the glycolide of low acid content.
Using technical scheme, a kind of polyethers is added as solvent in depolymerization, can prepare low impurity content
Glycolide, ring-type impurity content achieves preferable technique effect up to 400ppm.
Embodiment
Embodiments and advantages of the present invention are further illustrated with following non-limiting example.
[embodiment 1]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3kPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 451g.
500g Macrogol 600s are added into oligomer, depolymerization system vacuum 1kPa, stirs speed in 270 DEG C of reaction temperature
Under 200 revs/min, carry out reaction and prepare glycolide, reaction stops reaction after 3 hours, and collection is obtained into solidliquid mixture filtering, obtained
Glycolide crude product 401g, ring-type impurity content 312ppm is calculated using nuclear-magnetism.
[embodiment 2]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3KPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 454g.
500g PEG-4000s are added into oligomer, depolymerization system in 270 DEG C, vacuum 1.5KPa of reaction temperature,
Stir under 200 revs/min of speed, carry out reaction and prepare glycolide, reaction stops reaction after 4 hours, collection is obtained into solidliquid mixture mistake
Filter, obtains glycolide crude product 396g, ring-type impurity content 365ppm is calculated using nuclear-magnetism.
[embodiment 3]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3KPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 451g.
500g poly glycol monomethyl ether -500 are added into oligomer, depolymerization system is in 270 DEG C of reaction temperature, vacuum
1.5KPa, stir under 200 revs/min of speed, carry out reaction and prepare glycolide, reaction stops reaction after 4 hours, collection is obtained into solid-liquid and mixed
Compound filters, and obtains glycolide crude product 384g, ring-type impurity content 278ppm is calculated using nuclear-magnetism.
[embodiment 4]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3KPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 451g.
1000g poly glycol monomethyl ether -500 are added into oligomer, depolymerization system is in 270 DEG C of reaction temperature, vacuum
1.5KPa, stir under 200 revs/min of speed, carry out reaction and prepare glycolide, reaction stops reaction after 8 hours, collection is obtained into solid-liquid and mixed
Compound filters, and obtains glycolide crude product 424g, ring-type impurity content 72ppm is calculated using nuclear-magnetism.
[comparative example 1]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3KPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 454g.
By the glycolic acid oligomer in 270 DEG C, vacuum 1.5KPa of reaction temperature, stir under 200 revs/min of speed, carry out
Reaction prepares glycolide, and reaction stops reaction after 2 hours, obtains glycolide crude product 331g, it is miscellaneous that ring-type is calculated using nuclear-magnetism
Matter content 2400ppm.
[comparative example 2]
After adding 600g ethanol acid crystal and 3g stannous octoate catalysts into reactor, temperature rises to 90 DEG C from room temperature,
After solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to, are warming up to 210 DEG C after pre-polymerization 1h, after anhydrous steam, system is protected
Hold temperature and start to vacuumize.This process vacuum degree control is in 3KPa.After anhydrous steam, system keeps the state to continue to react
1.5h, obtain glycolic acid oligomer 451g.
The Polyethylene glycol-2000 that 500g is solid-state at room temperature is added into oligomer, depolymerization system is in reaction temperature 270
DEG C, vacuum 1.5KPa, stir under 200 revs/min of speed, carry out reaction and prepare glycolide, reaction stops reaction after 4 hours, obtains second friendship
Ester crude product 356g, ring-type impurity content 1280ppm is calculated using nuclear-magnetism.
Claims (10)
1. a kind of preparation method of glycolide, including glycolic polycondensation obtained into the condensation polymerization step of glycolic acid oligomer and by ethanol
Acid oligomer carries out depolymerization and obtains the depolymehzation step of glycolide；Wherein, the depolymehzation step specifically includes：Add into reaction system
Enter at least one polyether solvent, glycolic acid oligomer and polyether solvent is formed homogeneously, improve system reaction temperature extremely
230-270 DEG C, while vacuum is improved to 0.1-5KPa, the glycolic acid oligomer that polycondensation obtains is decomposed, be evaporated under reduced pressure,
Obtain glycolide.
2. preparation method for glycolide according to claim 1, it is characterised in that the condensation polymerization step comprises the following steps：a)
Normal pressure polycondensation, after ethanol acid crystal and catalyst are mixed, reaction temperature is kept to carry out polycondensation reaction at 110~220 DEG C, obtain
To polyglycolic acid；B) polycondensation is depressurized, after step a, keeps system temperature, while improves system vacuum to 0.1-5kPa, after
Continuous reaction 2h；C) strengthen polycondensation, after the stepb, keep system temperature and vacuum to continue to react 0.5-10 hours.
3. preparation method for glycolide according to claim 2, it is characterised in that catalyst used for tin halide or
The organic acid compound of tin, be either the oxide of antimony, the halide of antimony, antimony organic acid compound or be zinc oxidation
Thing, the halide of zinc, the complex of the organic compound of zinc or zinc, the either complex or dilute of organo-aluminum compound or aluminium
Earth metal complex, or be above two or two or more mixed catalysts, the dosage of catalyst is glycolic dosage
0.001-1wt%.
4. preparation method for glycolide according to claim 2, it is characterised in that the normal pressure condensation temperature is 110~220
℃。
5. preparation method for glycolide according to claim 2, it is characterised in that the vacuum of the decompression polycondensation is 0.1-
5kPa。
6. preparation method for glycolide according to claim 2, it is characterised in that the reinforcement polycondensation reaction time is in 0.5-
10 hours.
7. preparation method for glycolide according to claim 1, it is characterised in that described polyether solvent is that polyethers are low
Polymers, the polyether oligomers are liquid at room temperature.
8. preparation method for glycolide according to claim 1, it is characterised in that the amount that described polyether solvent adds is
The 10-500wt% of glycolic acid oligomer amount.
9. preparation method for glycolide according to claim 7, it is characterised in that the molecular structure of the polyethers quasi-oligomer
For R2O(-R1-O-)qR3, wherein R1For C1~C4Alkylidene in one kind；R2For H or C1~C4Alkyl in one kind；R3
For H or middle C1~C4Alkyl one kind；0<q<20.
10. preparation method for glycolide according to claim 1, it is characterised in that the vacuum 0.5- of the depolymerization reaction
5KPa。
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| WO2020087217A1 (en) * | 2018-10-29 | 2020-05-07 | Pujing Chemical Industry Co., Ltd | Glycolide production from methyl polyglycolate |
| WO2020087223A1 (en) * | 2018-10-29 | 2020-05-07 | Pujing Chemical Industry Co., Ltd | Novel polyglycolic acid and preparation method thereof by polycondensation |
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| CN114478472A (en) * | 2022-02-23 | 2022-05-13 | 中国科学院长春应用化学研究所 | Preparation method of glycolide |
| CN114478472B (en) * | 2022-02-23 | 2024-02-13 | 中国科学院长春应用化学研究所 | Preparation method of glycolide |
| CN114524796B (en) * | 2022-02-23 | 2024-03-26 | 中国科学院长春应用化学研究所 | Preparation method of glycolide |
| CN114805283A (en) * | 2022-04-29 | 2022-07-29 | 内蒙古久泰新材料有限公司 | Method for continuously and stably preparing high-quality glycolide |
| CN115073415A (en) * | 2022-05-31 | 2022-09-20 | 江苏景宏新材料科技有限公司 | Method for preparing high-purity glycolide |
| CN116283890A (en) * | 2023-03-29 | 2023-06-23 | 中国科学院长春应用化学研究所 | Preparation method and preparation device of glycolide |
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