CN105315155B - The method for preparing glycolic acid oligomer - Google Patents
The method for preparing glycolic acid oligomer Download PDFInfo
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- CN105315155B CN105315155B CN201410354627.7A CN201410354627A CN105315155B CN 105315155 B CN105315155 B CN 105315155B CN 201410354627 A CN201410354627 A CN 201410354627A CN 105315155 B CN105315155 B CN 105315155B
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Abstract
The present invention relates to a kind of preparation method of glycolic acid oligomer, mainly solve to prepare during glycolic acid oligomer that glycolate converting rate is relatively low in the prior art, the technical problem easily steamed in course of reaction, by using comprising the following steps：Ethanol acid crystal is subjected to normal pressure polycondensation reaction in atmospheric conditions first, untill anhydrous be distilled out；Then, decompression polycondensation reaction is carried out, proceeds condensation reaction or ester exchange reaction, until no water is distilled out；Wherein, the distillation uses distillation column, and the temperature of distillation column is 80~110 DEG C, and the theoretical cam curve of distillation column is 5 30 technical scheme, the problem is preferably resolved, available in the industrialized production of glycolide.
Description
Technical field
The present invention relates to a kind of production method of glycolic acid oligomer, it is prepared by polycondensation glycolic.Second
Alkyd oligomer is to prepare glycolide important source material, and glycolide is the most frequently used monomer for preparing HMW polyglycolic acid.
When preparing glycolic acid oligomer, the glycolate converting rate of reaction condition strong influence, by controlling heating speed
The structure of degree and decompression rate and distillation column, can be significantly reduced steaming for ethanol acid starting material, improve the conversion of glycolic
Rate.
Background technology
Glycolide is a kind of important compound that can be used for preparing polyglycolic acid and its copolymer, in recent years, due to poly-
Glycolic and its copolymer have biodegradability, and polyglycolic acid and polylactic-co-glycolic acid are even more a few
Available for clinical biomaterial thus receive much concern.The polyglycolic acid and its copolymer of HMW must opening by glycolide
Cyclopolymerization reacts to obtain.
Generally, the synthesis of cyclic ester monomers is generally divided into two steps：Pass through alpha-hydroxy carboxylic acid compounds (such as glycolic) polycondensation first
The polymer (hereinafter referred to as oligomer) of synthesis low molecule amount is used as intermediate；Then by the method cyclisation of high temperature distillation
Intermediate is stated to generate cyclic ester, and extracts from reaction system gaseous cyclic ester compounds.More specifically, glycolide is with second
Alkyd is raw material, is synthesized by following reactions steps.
(1) first it is dehydrated at ambient pressure, then under reduced pressure by glycolic heating until it is dehydrated and be condensed and changes into oligomer,
Such as formula [I].
(2) under reduced pressure, it is added thereto, together heats using oligomer and as the catalyst of glycolide synthesis, is inciting somebody to action
While reaction temperature is maintained at 220 DEG C to 290 DEG C, second is collected in the glycolide steam being born with separated, then cooling
Lactide steam, such as formula [II].
The composition of the thick glycolide reclaimed in aforementioned manners is with the retention time in reaction temperature, pressure, reaction, oligomer
Molecular weight, the species of used catalyst and consumption and change very big.During dehydrating polycondensation prepares oligomer, water is one
Directly exist in system.The presence of water can promote the hydrolysis of polyglycolic acid and cause the generation of acid ingredient, in later stage depolymerization
Cheng Zhonghui largely effects on the purity of the glycolide of generation；And it is the water that can fully remove, meeting and glycolide in polycondensation process
It is collected together.Water can promote the glycolide hydrolysis generation acid ingredient of generation, not only greatly reduce the yield of glycolide, together
When add difficulty for the Purification in later stage.In the ring-opening polymerisation of glycolide, in order to obtain the polyglycolic acid of HMW,
The glycolide monomer of high-purity must be used.
U.S. patent 2668162 discloses a kind of method, prepares polyglycolic acid by melt polycondensation at 170-185 DEG C first
Oligomer, is then broken into powder by glycolic acid oligomer, and 1.6-2.0kPa, in 270-285 DEG C of heating, is received under a high vacuum
Steam of the collection gained containing glycolide.The yield highest of thick glycolide can reach 93%, and the thick glycolide of gained further leads to
Cross solvent washing and multiple solvent recrystallization is purified.
U.S. patent 4727163 discloses a kind of method, and base material, Ran Houyi are made using the polyethers with good thermal stability
Alkyd carries out block copolymerization with base material and obtains block copolymer, and finally heated block copolymer carries out depolymerization.Yield is 67%.Though
Right high temperature resistant polyethers can lead to and can be reused, and favorably can have system to be heated evenly as the solvent in depolymehzation process, but
Need to expend substantial amounts of polynary polyethers, while polymer has many side reactions generations at high temperature, obtain in glycolide product
Introduce other impurity.
U.S. patent 4835293 discloses a kind of method, prepares polyglycolic acid by melt polycondensation at 170-185 DEG C first
Oligomer, then carries out depolymerization at ambient pressure, and the glycolide evaporated in bath surface is entrained with by nitrogen, and mixed gas is led to
Cross water insoluble non-polar solven to collect, yield 48%~62%.Because the generating rate of cyclic dimer is slower, this side
Method is difficult to reduce production cost
Patent CN101054371A discloses a kind of method, uses the ethanol acid crystal of high-purity for raw material, passes through dehydration
Polycondensation, melt polycondensation prepare glycolic acid oligomer, the oligomer of the gained high-temperature fusion under the catalysis of two kinds of catalyst
Depolymerization, the highest yield of thick glycolide can reach 86%.Crude product is obtained to purify by recrystallizing, and in crystallization process
Low boiling point solvent is added as nucleator, is conducive to glycolide crystals to separate out.This method is not suitable for large-scale production.
The numerous patents US5830991 of Wu Yu companies, US6891048B2, US691639B2, CN1496359A,
CN1501923A, addition high boiling point polar organic solvent can be used into glycolic acid oligomer to reduce reaction system by mentioning
Viscosity and depolymerization reaction temperature, also mention glycolic acid oligomer and polar organic solvent while adding depolymerization system and while drawing
Enter the sulfate and/or acylate stabilizer of divalence or multivalent cationic form to prevent the generation of side reaction, but this method
It result in and this kind of solvent is mixed with glycolide crude product and is difficult to purify.
Polyglycolic acid, as degradable poly ester material, is always the emphasis of research concern.Glycolide is to prepare HMW
Polyglycolic acid important monomer.Glycolide production cost how is reduced, the yield of glycolide is improved for exploitation polyglycolic acid
Production technology is highly important.When preparing glycolic acid oligomer by raw material of glycolic, melt polycondensation reaction process has water
Generation, while melt polycondensation reaction is a balanced reaction, in order to improve molecular weight, the reaction is needed in high temperature and condition of high vacuum degree
It is lower to carry out, balanced reaction is moved right, the water of generation efficiently separates out, such as formula [III].Under the reaction conditions, it is former
Material glycolic is relatively easy to be distilled out of together with water, so as to reduce the conversion ratio of glycolic, influences the ultimate yield of glycolide.
Thus when preparing glycolic acid oligomer, steaming for raw material how is reduced, preparation of the feed stock conversion for glycolide is improved
It is necessary.
The content of the invention
The technical problems to be solved by the invention are glycolate converting rates when preparing glycolic acid oligomer in the prior art
It is relatively low, there is provided a kind of production method for being used to produce the glycolic acid oligomer of glycolide easily the problem of steam in course of reaction,
It is the oligomer that glycolic is prepared by melt polycondensation glycolic, by controlling programming rate and decompression rate and distillation column
Structure, can be significantly reduced steaming for ethanol acid starting material, improve the conversion ratio of glycolic.
In order to solve the above technical problems, the present invention uses following technical scheme：A kind of preparation side of glycolic acid oligomer
Method, comprises the following steps：By ethanol acid crystal first in atmospheric conditions carry out normal pressure polycondensation, until it is anhydrous be distilled out for
Only；Then, decompression polycondensation reaction is carried out, proceeds condensation reaction or ester exchange reaction, until no water is distilled out；Its
In, the distillation uses distillation column, and the temperature of distillation column is 80~110 DEG C, and the theoretical cam curve of distillation column is 5-30.
In above-mentioned technical proposal, filler filling is preferably added in the distillation column；The filler preferably is selected from Raschig ring, Bauer
At least one of ring, Intalox saddle, ladder ring packing, dictyosome filler or ball-shaped filling material；The temperature of distillation column is preferably 100
℃。
In above-mentioned technical proposal, the normal pressure polycondensation reaction is preferably segmented to be carried out：First stage pre-polymerization, reaction temperature is preferred
Between the fusing point of glycolic and the boiling point of glycolic, the reaction time is preferably 0.5~10 hour, and more preferably 0.5~5 is small
When；Second stage polycondensation, preferably under 112~220oC of reaction temperature, more preferably under 140~210oC of reaction temperature, is carried out
Condensation reaction or ester exchange reaction, untill anhydrous steam.
In above-mentioned technical proposal, the reaction temperature of the decompression polycondensation reaction is preferably 112~220oC；Reaction pressure is excellent
Elect 0.1-5KPa, more preferably 0.1-3KPa as；The decompression rate of the decompression polycondensation reaction is preferably 0.1-5KPa/min, more
It is preferably 0.1-1KPa/min.
In above-mentioned technical proposal, preferably continue to carry out reinforcement polycondensation reaction after the decompression polycondensation reaction, strengthen polycondensation anti-
The reaction temperature answered is preferably 112~220oC；Reaction pressure is preferably 0.1-5KPa, more preferably 0.1-3KPa；Reaction time
Preferably 0.5-10 hours.
In above-mentioned technical proposal, further preferred scheme is：The programming rate of the decompression polycondensation reaction is preferably 0.6-
20 DEG C/min, more preferably 0.6-10 DEG C/min；The reaction vacuum of the decompression polycondensation is in 0.1-5KPa, preferably 0.1-
3KPa；The decompression rate of the decompression polycondensation reaction is 0.1-5KPa/min, preferably 0.1-1KPa/min；In the distillation column
Theoretical cam curve be preferably 5-20.
In above-mentioned technical proposal, most preferably scheme is：When the theoretical cam curve of distillation column is 10-20, programming rate 1
DEG C/min, during decompression rate 1KPa/min, the amount of steaming of glycolic can be very low, preferable to improving reaction conversion ratio.
The advantage of the invention is that：When preparing glycolic acid oligomer, pass through normal pressure polycondensation segmentation reaction, control decompression contracting
The programming rate and decompression rate of poly- course of reaction, can reduce the amount of steaming of glycolic, improve glycolic low to polyglycolic acid
The conversion of polymers；Filler filling is added in distillation column simultaneously, the separative efficiency of raw material and water can be improved, second is efficiently reduced
Content of the alkyd in system is distillated effectively improves the yield of glycolide.
Using technical scheme, reaction, control are segmented by normal pressure polycondensation and depressurize the heating of polycondensation process
Speed and decompression rate, and using the distillation that filler filling is added in distillation column, can effectively reduce second in course of reaction
Steaming for alkyd, improves glycolate converting rate, and receiving bottle collects ethanol acid content in liquid and is smaller than 10% in reaction, achieves
Preferable technique effect.
Brief description of the drawings
Distillating objects system includes water and ethanol acid starting material, by the refraction index (Refractive for determining the system that steams
Index), the amount of glycolic steamed is determined.Fig. 1 is the glycolic weight percentage determined to water and glycollic acid solution body
The refraction index figure of system, ordinate is refraction coefficient, and abscissa is glycolic weight percentage.
Further illustrated below by specific embodiment.
Embodiment
Embodiments and advantages of the present invention are further illustrated with following non-limiting example.
[embodiment 1]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 20 DEG C/min programming rate opens
200 DEG C are warming up to 20 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then with 4KPa/min's
Decompression rate improves vacuum to 3KPa, until without distillate, it is 14.5% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 2]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 15 DEG C/min programming rate opens
200 DEG C are warming up to 15 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then with 2KPa/min's
Decompression rate improves vacuum to 3KPa, until without distillate, it is 10.7% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 3]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 10 DEG C/min programming rate opens
200 DEG C are warming up to 10 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then with 2KPa/min's
Decompression rate improves vacuum to 3KPa, until without distillate, it is 8.9% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 4]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 5 DEG C/min programming rate opens
200 DEG C are warming up to 5 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then subtracting with 2KPa/min
Speed is pressed to improve vacuum to 3KPa, until without distillate, it is 7.5% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 5]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 1 DEG C/min programming rate opens
200 DEG C are warming up to 1 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then subtracting with 2KPa/min
Speed is pressed to improve vacuum to 3KPa, until without distillate, it is 5.6% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 6]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is 5.
Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and being warming up to 112 DEG C with 1 DEG C/min programming rate opens
200 DEG C are warming up to 1 DEG C/min programming rate after beginning pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then subtracting with 1KPa/min
Speed is pressed to improve vacuum to 3KPa, until without distillate, it is 4.7% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 7]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is
10.Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and 112 DEG C are warming up to 1 DEG C/min programming rate
200 DEG C are warming up to 1 DEG C/min programming rate after starting pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then with 1KPa/min's
Decompression rate improves vacuum to 3KPa, until without distillate, it is 4.1% that receiving bottle, which collects ethanol acid content in liquid,.
[embodiment 8]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is
15.Temperature of reaction system rises to 90 DEG C from room temperature, after solid is completely dissolved, and 112 DEG C are warming up to 1 DEG C/min programming rate
200 DEG C are warming up to 1 DEG C/min programming rate after starting pre-polymerization, pre-polymerization 2h, is steamed until anhydrous.Then with 1KPa/min's
Decompression rate improves vacuum to 3KPa, until without distillate, it is 0.7% that receiving bottle, which collects ethanol acid content in liquid,.
[comparative example 1]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor.Temperature of reaction system rises to from room temperature
90 DEG C, 200 DEG C are warming up to after 112 DEG C of beginning pre-polymerizations, pre-polymerization 2h are warming up to after solid is completely dissolved, is steamed until anhydrous.So
Reaction system vacuum is improved afterwards to 3KPa, until without distillate, it is 22.3% that receiving bottle, which collects ethanol acid content in liquid,.
[comparative example 2]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor.Temperature of reaction system rises to from room temperature
90 DEG C, after solid is completely dissolved, 112 DEG C of beginning pre-polymerizations are warming up to 1 DEG C/min programming rate, after pre-polymerization 2h with 1 DEG C/
Min programming rate is warming up to 200 DEG C, is steamed until anhydrous.Then vacuum is improved extremely with 1KPa/min decompression rate
3KPa, until without distillate, it is 18.7% that receiving bottle, which collects ethanol acid content in liquid,.
[comparative example 3]
400g ethanol acid crystal and 2g stannous octoate catalysts are added into reactor, the theoretical cam curve of distillation column is
15.Temperature of reaction system rises to 90 DEG C from room temperature, is risen after 112 DEG C of beginning pre-polymerizations, pre-polymerization 2h are warming up to after solid is completely dissolved
Temperature is steamed to 200 DEG C until anhydrous.Then reaction system vacuum is improved to 3KPa, until without distillate, receiving bottle is collected
Ethanol acid content is 13.9% in liquid.
Claims (6)
1. a kind of preparation method of glycolic acid oligomer, it is characterised in that comprise the following steps：Ethanol acid crystal is existed first
Normal pressure polycondensation reaction is carried out under condition of normal pressure, untill anhydrous be distilled out；Then, decompression polycondensation reaction is carried out, makes condensation
Reaction or ester exchange reaction proceed, until no water is distilled out；Wherein, the distillation uses distillation column, distillation column
Temperature is 80-110 DEG C, and the theoretical cam curve of distillation column is 5-30；
The normal pressure polycondensation reaction segmentation is carried out：First stage pre-polymerization, boiling of the reaction temperature in the fusing point and glycolic of glycolic
Between point, the reaction time is 0.5-10 hours；Second stage polycondensation, at 112-220 DEG C of reaction temperature, carry out condensation reaction or
Ester exchange reaction, untill anhydrous steam；
The decompression polycondensation reaction, is 112-220 DEG C in reaction temperature, and reaction pressure is progress under 0.1-5kPa；
The decompression rate of the decompression polycondensation reaction is 0.1-5kPa/min；The programming rate of the normal pressure polycondensation reaction is 0.6-
20℃/min。
2. glycolic acid oligomer preparation method according to claim 1, it is characterised in that add and fill out in the distillation column
Material filling.
3. glycolic acid oligomer preparation method according to claim 2, it is characterised in that the filler in distillation column is selected from
At least one of Raschig ring, Pall ring, Intalox saddle, ladder ring packing, dictyosome filler or ball-shaped filling material.
4. glycolic acid oligomer preparation method according to claim 1, it is characterised in that the reaction of the decompression polycondensation
Pressure is 0.1-3kPa.
5. according to the preparation method of any described glycolic acid oligomer of Claims 1 to 4, it is characterised in that the decompression contracting
Proceed to strengthen polycondensation reaction after poly- reaction.
6. according to the preparation method of the glycolic acid oligomer described in claim 5, it is characterised in that the reinforcement polycondensation reaction exists
Reaction temperature is 112-220 DEG C, and reaction pressure is progress under 0.1-5kPa, and the reaction time is 0.5-10 hours.
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| CN107151238A (en) * | 2016-03-05 | 2017-09-12 | 李坚 | Formates or method and application that carbonate is Material synthesis glycolide and glycolic acid oligomer |
| CN108558666A (en) * | 2018-05-14 | 2018-09-21 | 沈阳化工大学 | A kind of solid acid catalyst alkali modification synthesis dimerization methyl glycollate method |
| CN114790279A (en) * | 2021-01-26 | 2022-07-26 | 惠生工程（中国）有限公司 | Industrial production process method of polyglycolic acid oligomer |
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| US6245437B1 (en) * | 1996-07-19 | 2001-06-12 | Kureha Kagaku Kogyo K.K. | Gas-barrier composite film |
| DE10014854A1 (en) * | 2000-03-24 | 2001-10-11 | Dhw Deutsche Hydrierwerke Gmbh | Esterification of carboxylic acid with alcohol, using condensation column attached to reactor to provide quantitative removal of water of reaction and conversion |
| CN1703439A (en) * | 2002-10-08 | 2005-11-30 | 吴羽化学工业株式会社 | Process for producing aliphatic polyester |
| CN101054371A (en) * | 2007-05-24 | 2007-10-17 | 复旦大学 | Preparation method for glycolide |
| CN103242287A (en) * | 2013-05-24 | 2013-08-14 | 武汉大学 | Preparation method of glycolide |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6245437B1 (en) * | 1996-07-19 | 2001-06-12 | Kureha Kagaku Kogyo K.K. | Gas-barrier composite film |
| DE10014854A1 (en) * | 2000-03-24 | 2001-10-11 | Dhw Deutsche Hydrierwerke Gmbh | Esterification of carboxylic acid with alcohol, using condensation column attached to reactor to provide quantitative removal of water of reaction and conversion |
| CN1703439A (en) * | 2002-10-08 | 2005-11-30 | 吴羽化学工业株式会社 | Process for producing aliphatic polyester |
| CN101054371A (en) * | 2007-05-24 | 2007-10-17 | 复旦大学 | Preparation method for glycolide |
| CN103242287A (en) * | 2013-05-24 | 2013-08-14 | 武汉大学 | Preparation method of glycolide |
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