CN102807550A - Method for preparing medical high-purity lactide - Google Patents
Method for preparing medical high-purity lactide Download PDFInfo
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- CN102807550A CN102807550A CN2012102979332A CN201210297933A CN102807550A CN 102807550 A CN102807550 A CN 102807550A CN 2012102979332 A CN2012102979332 A CN 2012102979332A CN 201210297933 A CN201210297933 A CN 201210297933A CN 102807550 A CN102807550 A CN 102807550A
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Abstract
The invention relates to a method for preparing medical high-purity lactide. The method includes steps of fusion of crude lactide, primary molecular distillation and secondary molecular distillation. The method provided can realize continuous operation, is free of solvent, simple and environment-friendly in the whole purification process and can be used for preparation of medical high-purity lactide.
Description
Technical field
The present invention relates to field of fine chemical, particularly, relate to a kind of preparation method of high-purity medical rac-Lactide.
Background technology
POLYACTIC ACID is that the lactic acid that obtains with the fermentation of starch-based farm crop process modern biotechnology is raw material, the macromolecule resin that generates through special polyreaction again.POLYACTIC ACID has excellent biological compatibility and degradation property, can be degraded fully by the mikrobe of occurring in nature after the use, can slowly be absorbed metabolism by human body behind the implant into body.
POLYACTIC ACID medically can be used as medical surgical sewing thread of exempting to take out stitches, bone renovating material, drug controlled release material, artificial bone, artificial skin, ophthalmology embedded material etc. because of possessing excellent biological compatibility, biological degradability and non-toxic nature.At present, developed country's part poly-lactic acid products such as the U.S., European Union, Japan have passed through clinical and have begun the mass-producing application.
The synthesis material of POLYACTIC ACID is a rac-Lactide, mainly comprises: L-rac-Lactide, D-rac-Lactide, D, L-rac-Lactide and meso-rac-Lactide.At present, to the purifying of different purposes rac-Lactides, promptly prepare highly purified rac-Lactide and mainly contain two kinds of methods, medical rac-Lactide mainly comes purifying through solvent recrystallization technology, and general rac-Lactide is mainly realized purifying through technologies such as rectifying tower and fusion-crystallizations.
One Chinese patent application 01815139.6 (publication number is CN 1452618A) has been introduced the method for a kind of purifying rac-Lactide (or NSC 403079); Method comprises: crystallization control, extractive crystallization crude lactide in water medium; Separate the crystal suspension-s drying obtain and obtain wet lotion, and then the recrystallize drying prepares the rac-Lactide of purifying in the melting media.
One Chinese patent application 91103421.8 (publication number is CN 1056689A) relates to the evaporation method of air aided of purifying lactide, and this method makes lactide be separated with impurity as the steam component in the air-flow, obtains highly purified lactide through solvent wash again.
One Chinese patent application 200710135532.6 (publication number is CN101157680A) provides a kind of method of utilizing ethanol and two kinds of solvent recrystallization purifying of ETHYLE ACETATE rac-Lactide.
One Chinese patent application 94112795.8 (publication number is CN1112559A) has been introduced the method for a kind of separate lactide and Study of Meso-Lactide, thereby makes Study of Meso-Lactide generation hydrolysis and removal soluble in water through rac-Lactide is contacted with water.
One Chinese patent application 200710302479.4 (publication number is CN101468978) has been introduced a kind of method of purification of rac-Lactide; Comprise that the pure and mild solvent elution of water elution is pure and dry, the water washing process that washing is purified is that crude lactide is inserted in the water, mixes; Slough water again, obtain washing rac-Lactide; The pure solvent process of washing of solvent elution is that the washing rac-Lactide is put in the solvent, and mixing is sloughed solvent again, obtains smart rac-Lactide, after drying, obtains doing smart rac-Lactide.
One Chinese patent application 200910234132.X (publication number is CN101696204A) has further simplified the purification step of rac-Lactide on the basis of one Chinese patent application 200710302479.4; Through repeatedly washing the rac-Lactide that directly obtains certain quality; Yield reaches more than 80%; Optical purity is more than 98%, is used for POLYACTIC ACID viscosity-average molecular weight that polymerization obtains more than 80,000.
U.S. Pat 5521278 has been mentioned a kind of method of purifying rac-Lactide, and mainly through the fusion-crystallization purifying lactide, the rac-Lactide acid number that obtains is in 6meq/kg.
U.S. Pat 6326458 has been introduced a kind of purification process of industriallization rac-Lactide, mainly realizes serialization rac-Lactide purifying through rectification process.
Existing patented technology prepares highly purified rac-Lactide, and is not enough below main the existence:
1) all uses solvent in the technological process of one Chinese patent application 91103421.8,200710135532.6 and 200710302479.4 purifying rac-Lactides, had environmental protection and safety-problems;
2) one Chinese patent application 01815139.6,94112795.8,200710302479.4 and 200910234132.X have adopted the method for water extraction or washing to come the purifying rac-Lactide; Rac-Lactide is to water relatively responsive (especially under the certain temperature condition); Dimer or the lactic acid impurity that hydrolysis generates lactic acid takes place easily; Therefore water also hydrolysis rac-Lactide in separated and dissolved lactic acid or lactic acid oligomer causes the rac-Lactide product yield to descend and can't separate totally with impurity;
3) U.S. Pat 5521278 has been mentioned fusion-crystallization and rectification process purifying rac-Lactide with US6326458; The rac-Lactide acid number that obtains can reach in the 10meq/kg; The POLYACTIC ACID number-average molecular weight that polymerization obtains can reach the requirement of general POLYACTIC ACID between 5 ~ 100,000, but does not still reach requirement in the purity of medical field rac-Lactide; For example the number-average molecular weight general requirement of POLYACTIC ACID is more than 100,000 in fracture internal fixing field, and corresponding rac-Lactide acid number is in 1meq/kg.
Therefore, a kind of new method for preparing the high-purity medical rac-Lactide need be provided, solve the deficiency of prior art in practical application.
Summary of the invention
The object of the present invention is to provide a kind of preparation method of high-purity medical rac-Lactide.
The preparation method of high-purity medical rac-Lactide provided by the invention comprises: crude lactide fusion, one-level short-path distillation and secondary short-path distillation.
The preparation method of high-purity medical rac-Lactide of the present invention particularly, may further comprise the steps:
1) crude lactide fusion: crude lactide is placed melting plant, be furnished with nitrogen system, temperature remains on 100 ~ 150 ℃ and carries out fusion;
2) one-level short-path distillation: the crude lactide that will pass through the step 1) fusion injects the one-level molecular distillation apparatus, and distillation is carried out under 20 ~ 500Pa and 50 ~ 150 ℃ of conditions, residual light constituent in the crude rac-Lactide;
3) secondary short-path distillation: will pass through step 2) crude lactide of one-level short-path distillation injects the secondary molecular distillation apparatus, and distillation is carried out under 10 ~ 500Pa and 60 ~ 180 ℃ of conditions, and the rac-Lactide of purifying is collected in residual heavy constituent in the crude rac-Lactide.
In the aforesaid method:
In the step 1), said crude lactide need to refer to the crude lactide raw material of purifying, and staple has L-rac-Lactide, D-rac-Lactide, meso-rac-Lactide, lactic acid, moisture and lactic acid oligomer.
In the step 1), the nitrogen gas purity in the nitrogen system is greater than 99.99%.
In the step 1), the nitrogen system of melting plant preparation guarantees that material (said crude lactide) is in constant voltage 0.11 ~ 0.20MPa nitrogen protection state.Preferred 0.12 ~ the 0.18MPa of pressure, more preferably 0.18MPa.
In the step 1), melt temperature is preferred: 105 ~ 130 ℃.
Step 2) in, said light constituent is mainly the impurity composition that boiling point is lower than rac-Lactide, like water, lactic acid etc.
Step 2) in, distillation is preferably carried out under 20 ~ 300Pa and 50 ~ 130 ℃ of conditions.Or preferably under 30 ~ 80Pa and 90 ~ 110 ℃ of conditions, carry out.More preferably under 30 ~ 60Pa and 100 ~ 110 ℃ of conditions, carry out.
In the step 3), distillation is preferably carried out under 10 ~ 200Pa and 80 ~ 170 ℃ of conditions.Or preferably under 10 ~ 20Pa and 128 ~ 150 ℃ of conditions, carry out.More preferably under 10 ~ 20Pa and 135 ~ 150 ℃ of conditions, carry out.
In the step 3), said heavy constituent are mainly the impurity composition that boiling point is higher than rac-Lactide, like lactic acid oligomer etc.
The preparation method of high purity rac-Lactide of the present invention has following advantage:
1, different with the prior art for preparation method: prior art is mainly through method purifying lactides such as solvent recrystallization, washing, rectifying or fusion-crystallizations; The present invention adopts the technology of short-range molecular distillation to carry out the purifying of rac-Lactide, does not use solvent.
2, the present invention adopts the physical method purifying lactide, does not use other media such as solvent and water, and the high purity rac-Lactide acid number that obtains can be controlled in the 0.5meq/kg, be suitable for medical, the simple environmental protection of method.
3, purifying process of the present invention can be realized serialization production, and the purity of the rac-Lactide that obtains can reach the medical grade requirement; Though the rectificating method in the existing patent also can serialization production, the purity of the rac-Lactide that rectificating method obtains does not reach the medical grade requirement.
Embodiment
Following examples are used to explain the present invention, but are not used for limiting scope of the present invention.
Nitrogen gas purity in the embodiment of the invention nitrogen system is all greater than 99.99%.
Firsts and seconds molecular distillation apparatus of the present invention is the KD50 of U.S. POPE company.Other operational conditions that in the preparation process, relate to are the routine of this area and select.
Embodiment 1
1, raw material is thick L-rac-Lactide, purity 92.50%wt, and other composition comprises: lactic acid 5.74%wt, meso-rac-Lactide 0.84%wt, D-rac-Lactide 0.2%wt, moisture 0.15%wt, lactic acid oligomer 0.57%wt.
2, the preparation technology of high purity rac-Lactide is:
1) crude lactide raw materials melt: the thick L-rac-Lactide raw material of 500kg is placed storage tank, and storage tank is furnished with nitrogen system, guarantees that material is in constant voltage 0.15MPa nitrogen protection state; Tank temperature remains on the 105 ℃ of thick L-rac-Lactide of fusion raw materials.
2) one-level short-path distillation: the thick L-rac-Lactide of fused raw material injects the one-level molecular distillation apparatus continuously through pump; Distillation is carried out under 80Pa and 90 ℃ of conditions, residual light constituent (comprising lactic acid, meso-rac-Lactide and moisture) in the crude L-rac-Lactide raw material.
3) secondary short-path distillation: the thick L-rac-Lactide raw material of one-level short-path distillation is injected the secondary molecular distillation apparatus continuously through pump; Distillation is carried out under 20Pa and 128 ℃ of conditions; Heavy constituent residual in the crude L-rac-Lactide raw material (comprise lactic acid oligomer and D; L-rac-Lactide [D, the L-rac-Lactide refers in particular to the blend of 50%D-rac-Lactide and 50%L-rac-Lactide]), collect the L-rac-Lactide of purifying.
3, the refining L-rac-Lactide index for preparing is: L-rac-Lactide 99.90%wt, lactic acid 0.04%wt, meso-rac-Lactide 0.03%wt, moisture 0.01%wt, lactic acid oligomer 0.02%wt; Content of carboxyl end group (acid number of high purity rac-Lactide) is 0.32meq/kg.
Embodiment 2
1, raw material is with embodiment 1.
2, the preparation technology of high purity rac-Lactide is:
1) crude lactide raw materials melt: the thick L-rac-Lactide raw material of 500kg is placed storage tank, and storage tank is furnished with nitrogen system, guarantees that material is in constant voltage 0.12MPa nitrogen protection state; Tank temperature remains on the 105 ℃ of thick L-rac-Lactide of fusion raw materials.
2) one-level short-path distillation: the thick L-rac-Lactide of fused raw material injects the one-level molecular distillation apparatus continuously through pump; Distillation is carried out under 60Pa and 90 ℃ of conditions, residual light constituent (comprising lactic acid, meso-rac-Lactide and moisture) in the crude L-rac-Lactide raw material.
3) secondary short-path distillation: the thick L-rac-Lactide raw material of one-level short-path distillation is injected the secondary molecular distillation apparatus continuously through pump; Distillation is carried out under 10Pa and 128 ℃ of conditions; Heavy constituent residual in the crude L-rac-Lactide raw material (comprise lactic acid oligomer and D; L-rac-Lactide [D, the L-rac-Lactide refers in particular to the blend of 50%D-rac-Lactide and 50%L-rac-Lactide]), collect the L-rac-Lactide of purifying.
3, the refining L-rac-Lactide index for preparing is: L-rac-Lactide 99.95%wt, lactic acid 0.02%wt, meso-rac-Lactide 0.01%wt, moisture 0.01%wt, lactic acid oligomer 0.01%wt; Content of carboxyl end group 0.25meq/kg.
Embodiment 3
1, raw material is with embodiment 1.
2, the preparation technology of high purity rac-Lactide is:
1) crude lactide raw materials melt: the thick L-rac-Lactide raw material of 500kg is placed storage tank, and storage tank is furnished with nitrogen system, guarantees that material is in constant voltage 0.18MPa nitrogen protection state; Tank temperature remains on the 105 ℃ of thick L-rac-Lactide of fusion raw materials.
2) one-level short-path distillation: the thick L-rac-Lactide of fused raw material injects the one-level molecular distillation apparatus continuously through pump; Distillation is carried out under 60Pa and 100 ℃ of conditions, residual light constituent (comprising lactic acid, meso-rac-Lactide and moisture) in the crude L-rac-Lactide raw material.
3) secondary short-path distillation: the thick L-rac-Lactide raw material of one-level short-path distillation is injected the secondary molecular distillation apparatus continuously through pump; Distillation is carried out under 10Pa and 135 ℃ of conditions; Heavy constituent residual in the crude L-rac-Lactide raw material (comprise lactic acid oligomer and D; L-rac-Lactide [D, the L-rac-Lactide refers in particular to the blend of 50%D-rac-Lactide and 50%L-rac-Lactide]), collect the L-rac-Lactide of purifying.
3, the refining L-rac-Lactide index for preparing is: L-rac-Lactide 99.97%wt, and lactic acid 0.01%wt, meso-rac-Lactide 0.01%wt, lactic acid oligomer 0.01%wt, moisture are 0; Content of carboxyl end group 0.13meq/kg.
Embodiment 4
1, raw material is thick D, the L-rac-Lactide, and purity 93.00%wt, other composition comprises: lactic acid 4.50%wt, meso-rac-Lactide 1.60%wt, moisture 0.20%wt, lactic acid oligomer 0.70%wt.
2, the preparation technology of high purity rac-Lactide is:
1) crude lactide raw materials melt: with the thick D of 500kg, L-rac-Lactide raw material places storage tank, and storage tank is furnished with nitrogen system, guarantees that material is in constant voltage 0.18MPa nitrogen protection state; Tank temperature remains on 130 ℃ of thick D of fusion, L-rac-Lactide raw material.
2) one-level short-path distillation: the thick D of fused; L-rac-Lactide raw material injects the one-level molecular distillation apparatus continuously through pump; Distillation is carried out under 50Pa and 110 ℃ of conditions, crude D, residual light constituent (comprising lactic acid, meso-rac-Lactide and moisture) in the L-rac-Lactide raw material.
3) secondary short-path distillation: with the thick D of one-level short-path distillation; L-rac-Lactide raw material injects the secondary molecular distillation apparatus continuously through pump; Distillation is carried out under 20Pa and 140 ℃ of conditions, crude D, residual heavy constituent (lactic acid oligomer) in the L-rac-Lactide raw material; Collect the D of purifying, the L-rac-Lactide.
3, the refining D for preparing, L-rac-Lactide index is: D, L-rac-Lactide 99.93%wt, lactic acid 0.02%wt, meso-rac-Lactide 0.02%wt, moisture 0.01%wt, lactic acid oligomer 0.02%wt; Content of carboxyl end group 0.27meq/kg.
Embodiment 5
1, raw material is with embodiment 4.
2, the preparation technology of high purity rac-Lactide is:
1) crude lactide raw materials melt: with the thick D of 500kg, L-rac-Lactide raw material places storage tank, and storage tank is furnished with nitrogen system, guarantees that material is in constant voltage 0.18MPa nitrogen protection state; Tank temperature remains on 130 ℃ of thick D of fusion, L-rac-Lactide raw material.
2) one-level short-path distillation: the thick D of fused; L-rac-Lactide raw material injects the one-level molecular distillation apparatus continuously through pump; Distillation is carried out under 30Pa and 110 ℃ of conditions, crude D, residual light constituent (comprising lactic acid, meso-rac-Lactide and moisture) in the L-rac-Lactide raw material.
3) secondary short-path distillation: with the thick D of one-level short-path distillation; L-rac-Lactide raw material injects the secondary molecular distillation apparatus continuously through pump; Distillation is carried out under 20Pa and 150 ℃ of conditions, crude D, residual heavy constituent (lactic acid oligomer) in the L-rac-Lactide raw material; Collect the D of purifying, the L-rac-Lactide.
3, the refining D for preparing, L-rac-Lactide index is: D, L-rac-Lactide 99.97%wt, lactic acid 0.01%wt, meso-rac-Lactide 0.01%wt, lactic acid oligomer 0.01%wt, moisture are 0; Content of carboxyl end group 0.15meq/kg.
Claims (10)
1. the preparation method of a high-purity medical rac-Lactide is characterized in that, comprising: crude lactide fusion, one-level short-path distillation and secondary short-path distillation.
2. method according to claim 1 is characterized in that, may further comprise the steps:
1) crude lactide fusion: under the condition of nitrogen protection, temperature remains on 100 ~ 150 ℃ and carries out fusion with crude lactide;
2) one-level short-path distillation: the crude lactide that will pass through the step 1) fusion injects the one-level molecular distillation apparatus, and distillation is carried out under 20 ~ 500Pa and 50 ~ 150 ℃ of conditions, residual light constituent in the crude rac-Lactide;
3) secondary short-path distillation: will pass through step 2) crude lactide of one-level short-path distillation injects the secondary molecular distillation apparatus, and distillation is carried out under 10 ~ 500Pa and 60 ~ 180 ℃ of conditions, and the rac-Lactide of purifying is collected in residual heavy constituent in the crude rac-Lactide.
3. method according to claim 2 is characterized in that, in the step 1), the purity of said nitrogen is greater than 99.99%.
4. according to claim 2 or 3 described methods, it is characterized in that in the step 1), the pressure of nitrogen protection condition is 0.11 ~ 0.20MPa.
5. method according to claim 4 is characterized in that, said pressure is 0.12 ~ 0.18MPa.
6. according to any described method of claim 2 ~ 5, it is characterized in that in the step 1), melt temperature is: 105 ~ 130 ℃.
7. according to any described method of claim 2 ~ 6, it is characterized in that step 2) in, distillation is carried out under 20 ~ 300Pa and 50 ~ 130 ℃ of conditions.
8. method according to claim 7 is characterized in that step 2) in, distillation is carried out under 30 ~ 80Pa and 90 ~ 110 ℃ of conditions.
9. according to any described method of claim 2 ~ 8, it is characterized in that in the step 3), distillation is carried out under 10 ~ 200Pa and 80 ~ 170 ℃ of conditions.
10. method according to claim 9 is characterized in that, in the step 3), distillation is carried out under 10 ~ 20Pa and 128 ~ 150 ℃ of conditions.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107531663A (en) * | 2015-04-30 | 2018-01-02 | 荷兰普拉克公司 | The method and apparatus for manufacturing lactide |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4075085B2 (en) * | 1996-10-25 | 2008-04-16 | トヨタ自動車株式会社 | Method for producing lactide |
| CN101696203A (en) * | 2009-10-26 | 2010-04-21 | 江苏科技大学 | Method for continuously refining L-lactide from crude L-lactide |
| CN102020628A (en) * | 2011-01-06 | 2011-04-20 | 云南富集生物材料科技有限公司 | Improved method of preparation process of polylactic acid midbody lactide |
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2012
- 2012-08-20 CN CN201210297933.2A patent/CN102807550B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4075085B2 (en) * | 1996-10-25 | 2008-04-16 | トヨタ自動車株式会社 | Method for producing lactide |
| CN101696203A (en) * | 2009-10-26 | 2010-04-21 | 江苏科技大学 | Method for continuously refining L-lactide from crude L-lactide |
| CN102020628A (en) * | 2011-01-06 | 2011-04-20 | 云南富集生物材料科技有限公司 | Improved method of preparation process of polylactic acid midbody lactide |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107531663A (en) * | 2015-04-30 | 2018-01-02 | 荷兰普拉克公司 | The method and apparatus for manufacturing lactide |
| CN107531663B (en) * | 2015-04-30 | 2022-02-08 | 荷兰普拉克公司 | Method and apparatus for producing lactide |
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