CN113004499B - Biodegradable polyester elastomer and preparation method and application thereof - Google Patents
Biodegradable polyester elastomer and preparation method and application thereof Download PDFInfo
- Publication number
- CN113004499B CN113004499B CN202110299987.1A CN202110299987A CN113004499B CN 113004499 B CN113004499 B CN 113004499B CN 202110299987 A CN202110299987 A CN 202110299987A CN 113004499 B CN113004499 B CN 113004499B
- Authority
- CN
- China
- Prior art keywords
- polyester elastomer
- polymalic acid
- reverse
- polyethylene glycol
- polycondensation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/06—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from hydroxycarboxylic acids
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/05—Alcohols; Metal alcoholates
- C08K5/053—Polyhydroxylic alcohols
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/06—Ethers; Acetals; Ketals; Ortho-esters
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
The invention discloses a preparation method of a biodegradable polyester elastomer. According to the method, polyethylene glycol or 1, 14-tetradecanediol is used as a crosslinking agent to form a crosslinking system with the polymalic acid, and a chemical network in the polymalic acid is constructed to prepare the polyester elastomer. The polyester elastomer disclosed by the invention is high in strength and large in elongation at break, can be biodegraded due to the existence of polymalic acid, has good toughness due to the existence of polyethylene glycol, is superior to the strength of a common polyester elastomer, has shape memory performance, and is suitable for the field of flexible wearable intelligent materials.
Description
Technical Field
The invention belongs to the technical field of preparation of high polymer materials, and relates to a biodegradable polyester elastomer, and a preparation method and application thereof.
Background
L-malic acid is a biomass that can be derived from eggshells or fresh fruits and has been industrialized by chemical or biosynthetic means, widely used in the food, beverage, pharmaceutical, chemical and medical industries. Poly L-malic acid (PLMA) or copolymers based on L-malic acid are derivatives of L-malic acid whereas the synthesis of poly malic acid is not so easy. If ring-opening polymerization is used, many reaction steps are involved, whereas only low molecular weight polymers can be obtained using direct polycondensation. Therefore, the research on polymalic acid is mainly focused on the copolymerization or grafting of polymalic acid with other biodegradable aliphatic polyesters, aiming at improving the molecular weight and mechanical strength of the polymalic acid in order to find possible applications in the biomedical field.
The polymalic acid has a large number of active sites in the backbone. Thus, modification of polymalic acid can be achieved in a variety of ways, not just chain extension. Crosslinking is also a good option for improving the overall properties of the polymalic acid. However, the crosslinking of polymalic acid is currently mainly around plastic articles ([1] Qiu YX, Wanyan QR, Xie WY, et al, Green and biobased-derived Materials with controllable Shape Memory transition temperature treated based on cross-linked poly (L-male acid) Polymer 2019; 180: 121733; [2] Yanxin Qiu, Qianru Wanyan, Wenting Zhang, et al, Programmabable and Sophimed Shape-Memory device video tissue modification Distribution of Polymer Cross crack. journal of Materials Chemistry A, ion, 8,17193 17201. the above method uses fatty diol as crosslinking agent, the above method uses large transition strength, but the glass transition strength is not much higher, and the recovery of Shape is not much more limited at room temperature, the above method also uses a material with a high glass transition temperature, and the above-mentioned material has a very low elongation at room temperature.
The polyethylene glycol has good water solubility and good compatibility with a plurality of organic components. They have excellent lubricity, moisture retention and dispersibility, can be used as adhesives, antistatic agents, softeners and the like, and are widely applied to industries such as cosmetics, pharmacy, chemical fibers and the like.
Disclosure of Invention
The invention aims to provide a biodegradable polyester elastomer, and a preparation method and application thereof. The polyester elastomer has high strength, large elongation at break, degradability and shape memory property.
The technical scheme for realizing the purpose of the invention is as follows:
the preparation method of the biodegradable polyester elastomer takes polyethylene glycol or 1, 14-tetradecanediol as a cross-linking agent to construct a chemical network in poly-L-malic acid, and comprises the following steps:
1) melting a malic acid monomer in an oil bath at 130 +/-5 ℃, then polycondensing at 110 +/-2 ℃ and 133 +/-5 Pa in vacuum state, and stirring for reacting for 45 +/-5 hours;
2) dissolving the reactant obtained by the polycondensation in the step 1) in tetrahydrofuran, adding the tetrahydrofuran into a reverse precipitator for precipitation for 10 +/-2 hours, and drying the obtained precipitate at 50 +/-5 ℃;
3) adding the polymalic acid obtained by the polycondensation into a reaction kettle, adding polyethylene glycol 300 or 1, 14-tetradecanediol, carrying out vacuum pumping reaction at 130 +/-2 ℃ for 15-45 min, and curing at 130 +/-2 ℃ for 4-24 h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
In the step 1), melting is carried out under 130 +/-5 ℃ oil bath, vacuum pumping reaction is carried out at 110 +/-2 ℃, and the reaction is slowly carried out at too low temperature, so that an expected product cannot be obtained; when the temperature is too high, byproducts are easily generated, so that the purity of the product is reduced.
In the step 1), the stirring speed is 200 +/-20 r/min.
In the step 2), the reverse precipitator is a mixture of petroleum ether and anhydrous ether, and the mass ratio of the petroleum ether to the anhydrous ether is 1: 0.90-1.10, wherein the volume of the reverse precipitator is 9-10 times of that of tetrahydrofuran. The step can remove the unreacted malic acid monomer, and the obtained product has uniform molecular weight and high yield.
In the step 3), the reaction conditions need to be strictly controlled, so that the ideal cross-linked polymalic acid can be obtained; the material needs to be fully cured to achieve stable performance, and the curing time is 22 +/-2 h.
In the step 3), the dosage of the polyethylene glycol is measured according to the polymalic acid in the reactant obtained by in-situ polymerization, and the ratio of the polymalic acid to the carboxyl hydroxyl of the polyethylene glycol or the 1, 14-tetradecanediol is 1: 0.5.
compared with the prior art, the invention has the following advantages:
according to the invention, the network geometry of the crosslinked PLMA is adjusted by adjusting and controlling the chain lengths of the crosslinking agents polyethylene glycol and 1, 14-tetradecanediol, so that the mechanical property of the polyester elastomer is adjusted and controlled. The polyester elastomer prepared by the method has high strength and large elongation at break, can be degraded due to the existence of polymalic acid, has good toughness due to the existence of polyethylene glycol and 1, 14-tetradecanediol, has strength superior to that of a common polyester elastomer, has shape memory performance, and is suitable for the field of flexible wearable intelligent materials.
Drawings
FIG. 1 is a weight diagram of materials prepared in examples 1 and 2 and comparative examples 1, 2 and 5.
Fig. 2 is a stress/strain diagram of the materials prepared in comparative examples 1, 2, 5.
Fig. 3 is a stress/strain diagram of the materials prepared in examples 1 and 2 and comparative examples 3 and 4.
FIG. 4 is a diagram showing a shape memory process of the material prepared in example 1.
Detailed Description
The present invention will be described in more detail with reference to the following examples and the accompanying drawings.
Example 1
(1) Melting 28g of malic acid monomer in an oil bath at 130 ℃, polycondensing at 110 ℃ under 133Pa vacuum, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 4.5g of polymalic acid obtained by the polycondensation, adding into a reaction kettle, 2.893g of polyethylene glycol 300, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Example 2
(1) Melting 28g of malic acid monomer in an oil bath at 130 ℃, polycondensing at 110 ℃ under 133Pa vacuum, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 4.5g of polymalic acid obtained by the polycondensation, adding into a reaction kettle, 2.231g of 1, 14-tetradecanediol, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Comparative example 1
(1) Melting 28g of malic acid monomer in 130 ℃ oil bath, polycondensing at 110 ℃ under 133Pa vacuum state, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) And dissolving the reactant obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring the reactant into 1300ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 6.0g of polymalic acid obtained by the polycondensation, adding the polymalic acid into a reaction kettle, adding 1.363g of polyethylene glycol 100, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Comparative example 2
(1) Melting 28g of malic acid monomer in 130 ℃ oil bath, polycondensing at 110 ℃ under 133Pa vacuum state, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 5g of polymalic acid obtained by polycondensation, adding the polymalic acid into a reaction kettle, 2.143g of polyethylene glycol 200, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Comparative example 3
(1) Melting 28g of malic acid monomer in 130 ℃ oil bath, polycondensing at 110 ℃ under 133Pa vacuum state, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 4g of polymalic acid obtained by polycondensation, adding into a reaction kettle, 3.448g of polyethylene glycol 400, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Comparative example 4
(1) Melting 28g of malic acid monomer in 130 ℃ oil bath, polycondensing at 110 ℃ under 133Pa vacuum state, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 4.5g of polymalic acid obtained by polycondensation, adding into a reaction kettle, 2.893g of polyethylene glycol 300, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 4h in nitrogen atmosphere to obtain the biodegradable polyester elastomer.
Comparative example 5
(1) Melting 28g of malic acid monomer in an oil bath at 130 ℃, polycondensing at 110 ℃ under 133Pa vacuum, stirring at the rotation speed of 200r/min, and reacting for 45 h.
(2) Dissolving the polymalic acid obtained by the polycondensation in 150ml of tetrahydrofuran, and pouring into 1500ml of reverse precipitator for precipitation for 12 hours, wherein the reverse precipitator is petroleum ether: the mass ratio of the anhydrous ether is 1: 1 and drying the obtained precipitate in a vacuum drying oven at 40 ℃.
(3) Weighing 6g of polymalic acid obtained by the polycondensation, adding the polymalic acid into a reaction kettle, adding 1.344g of 1, 5-pentanediol, carrying out vacuum pumping reaction at 130 ℃ for 15min, and curing at 130 ℃ for 24h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
The products obtained in examples 1 and 2 and comparative examples 1, 2, 3, 4 and 5 were of the same morphology. FIG. 1 shows visually the fact that the materials prepared in examples 1 and 2 and comparative examples 1, 2 and 5 were stretched under a weight of 50g, and it can be seen that the material prepared in example 1 has the best tensile properties, followed by example 2; the material prepared in comparative example 1 had almost no stretching phenomenon; comparative example 2 the material prepared was more stretchable than comparative example 1, but was still less stretchable than examples 1 and 2. In addition, the tensile strength of the materials obtained in comparative examples 3 and 4 was weak and could not withstand the tensile force of a 50g weight.
FIG. 2 is a stress-strain curve of the composites prepared in comparative examples 1, 2, 5, and it can be seen that all the samples have higher strength but lower elongation at break, not more than 40%.
It can be seen from the comparison of example 1 and comparative examples 1 to 3 that the chain length of the polyethylene glycol as the crosslinking agent affects the mechanical properties of the finally prepared polyester elastomer, that when the chain length is too short (100 to 200), the tensile property of the prepared polyester elastomer is poor, and when the chain length is too long (400), the strength of the prepared polyester elastomer is weak. It can be seen from the comparison of example 1 and comparative example 4 that the curing time also affects the mechanical properties of the finally obtained polyester elastomer, and when the curing time is too short (4h), the overall tensile properties of the obtained polyester elastomer are weaker. As can be seen from the comparison of example 1 and comparative example 5, the choice of the crosslinking agent also affects the mechanical properties of the finally obtained polyester elastomer. The polyester elastomer prepared by using 1, 5-pentanediol as a crosslinking agent has high strength, but has low elongation at break.
Fig. 3 is a stress-strain curve of the composite materials prepared in examples 1 and 2 and comparative examples 3 and 4, and it can be seen that both examples 1 and 2 exhibit good elongation at break, with example 1 having an elongation at break of up to 110% and example 2 having an elongation at break of about 90%, but having a higher strength than example 1. The elongation at break of comparative example 3 is only 85%, and the strength and elongation at break of comparative example 4 are very low. The materials obtained in examples 1 and 2 therefore have the best overall properties.
FIG. 4 is a graph showing the shape memory properties of the material of example 1, the original shape of which is shown in FIG. 4(a), the material being heated above its glass transition temperature to change its shape and cooled below its glass transition temperature to fix its temporary shape, FIG. 4 (b); and increasing the temperature to be higher than the glass transition temperature, and recovering the temporary shape to the original shape, as shown in fig. 4(c), which shows that the polyester elastomer prepared by the method of the invention has good shape memory performance and is suitable for the field of flexible wearable intelligent material preparation.
The present invention is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts according to the disclosed technical contents, and these substitutions and modifications are all within the protection scope of the present invention.
Claims (8)
1. A method for producing a biodegradable polyester elastomer, characterized by comprising the steps of:
1) melting a malic acid monomer in an oil bath at 130 +/-5 ℃, then polycondensing at 110 +/-2 ℃ and 133 +/-5 Pa in vacuum state, and stirring for reacting for 45 +/-5 hours;
2) dissolving the reactant obtained by the polycondensation in the step 1) in tetrahydrofuran, adding the tetrahydrofuran into a reverse precipitator for precipitation for 10 +/-2 hours, and drying the obtained precipitate at 50 +/-5 ℃;
3) adding the polymalic acid obtained by the polycondensation into a reaction kettle, adding polyethylene glycol 300 or 1, 14-tetradecanediol, carrying out vacuum pumping reaction at 130 +/-2 ℃ for 15-45 min, and curing at 130 +/-2 ℃ for 22 +/-2 h in a nitrogen atmosphere to obtain the biodegradable polyester elastomer.
2. The method according to claim 1, wherein the stirring speed in step 1) is 200 ± 20 r/min.
3. The method according to claim 1, wherein in step 2), the reverse precipitant is a mixture of petroleum ether and dehydrated ether.
4. The method according to claim 3, wherein in the step 2), the mass ratio of the petroleum ether to the dehydrated ether is 1: 0.90 to 1.10.
5. The method according to claim 1, wherein the volume of the reverse precipitant in the step 2) is 9 to 10 times that of tetrahydrofuran.
6. The method according to claim 1, wherein in step 3), the ratio of the carboxyl groups of the polymalic acid to the polyethylene glycol or 1, 14-tetradecanediol is 1: 0.5.
7. the polyester elastomer obtained by the production process according to any one of claims 1 to 6.
8. Use of the polyester elastomer of claim 7 in the preparation of flexible wearable smart materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110299987.1A CN113004499B (en) | 2021-03-22 | 2021-03-22 | Biodegradable polyester elastomer and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110299987.1A CN113004499B (en) | 2021-03-22 | 2021-03-22 | Biodegradable polyester elastomer and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113004499A CN113004499A (en) | 2021-06-22 |
| CN113004499B true CN113004499B (en) | 2022-03-15 |
Family
ID=76403869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110299987.1A Active CN113004499B (en) | 2021-03-22 | 2021-03-22 | Biodegradable polyester elastomer and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113004499B (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101328259B (en) * | 2008-07-31 | 2011-07-06 | 绍兴文理学院 | Preparation of biodegradable fermentation organic acid ployester |
| CN108586715A (en) * | 2018-04-20 | 2018-09-28 | 浙江大学 | A kind of biological poly ester elastomer and preparation method thereof |
-
2021
- 2021-03-22 CN CN202110299987.1A patent/CN113004499B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113004499A (en) | 2021-06-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2419673C (en) | Polymeric networks | |
| Hu et al. | Fully bio-based poly (propylene succinate-co-propylene furandicarboxylate) copolyesters with proper mechanical, degradation and barrier properties for green packaging applications | |
| Wu et al. | Biobased poly (butylene 2, 5-furandicarboxylate) and poly (butylene adipate-co-butylene 2, 5-furandicarboxylate) s: From synthesis using highly purified 2, 5-furandicarboxylic acid to thermo-mechanical properties | |
| WO2009015577A1 (en) | Producing method for polylactic acid-based copolymer | |
| CN108395527B (en) | Azobenzene polyether ester multi-block copolymer elastomer with photoinduced deformation performance and preparation method thereof | |
| CN113087884A (en) | Method for preparing poly (butylene succinate) | |
| Qiu et al. | Thermal behavior, mechanical and rheological properties, and hydrolytic degradation of novel branched biodegradable poly (ethylene succinate) copolymers | |
| KR20200126790A (en) | Process for preparation of block copolymer | |
| JP5223347B2 (en) | Resin composition, method for producing the same, and copolymer | |
| KR20210038251A (en) | Method for preparing poly(3-hydroxypropionate) using terminal group modifying material | |
| CN113004499B (en) | Biodegradable polyester elastomer and preparation method and application thereof | |
| CN115322350B (en) | Degradable bio-based polyester and preparation method and application thereof | |
| CN109320699B (en) | Thermoplastic aliphatic-aromatic copolyester elastomer and preparation method thereof | |
| CN114222717A (en) | Polyester polymer nanocomposites | |
| JP4390273B2 (en) | Biodegradable resin composition | |
| KR102350740B1 (en) | Acetylated lactide oligomer-based plasticizer and the method of manufacturing the same, pla resin composition comprising acetylated lactide oligomer-based plasticizer | |
| Zhou et al. | A green and efficient synthetic strategy for the preparation of PBS ionomers with high molecular weight, high ionic group content and good combined properties | |
| CN104558542B (en) | A kind of transparent elastic copolymer of poly lactic acid and preparation method | |
| Pholharn et al. | Optimizationof poly (L-lactide)-polybutylene adipate terephthalate diblockcopolymer by ring opening polymerization | |
| CN1621433A (en) | Process for preparing high-molecular lactic acid copolymer | |
| Lee et al. | Synthesis and characterisation of PLLA by melt polycondensation using binary catalyst system | |
| JPS6031525A (en) | Production of high-viscosity polyester block copolymer | |
| CN116120532B (en) | Preparation method of poly (butylene succinate) and poly (butylene succinate) | |
| CN115232315B (en) | Polyglycolic acid/aliphatic polycarbonate multiblock copolymer and preparation method thereof | |
| CN112778548B (en) | Reversibly crosslinked aliphatic polyesters and process for their preparation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |