A triblock polyester material, its synthesis and use

Abstract

The application discloses a kind of tri-block polyester materials and its synthesis method and application.The application belongs to the field of block polyester materials and synthesis.The application is to solve the technical problem that random transesterification leads to random sequence.The application utilizes the difference between different polymers in transesterification capacity, and synthesizes tri-block copolymer by sequential transesterification reaction, realizes the recycling of waste polyester materials, reduces plastic pollution caused by large use of polyester materials to a certain extent, realizes the recycling of plastic, and provides a method for synthesizing new materials.The application is suitable for recycling of polyester products.The obtained tri-block copolymer can be used as thermoplastic elastomer after chain extension.

Description

Technical Field

[0001] This invention belongs to the field of block polyester materials and their synthesis, specifically relating to a triblock polyester material, its synthesis method, and its application. Background Technology

[0002] Block copolymers are polymers formed by polymerizing two or more different monomers. They combine the excellent properties of multiple polymers to obtain functional polymer materials with superior performance. These polymers, with controllable molecular weight, narrow molecular weight distribution, and designable molecular structure and composition, represent one of the most significant and challenging research areas in polymer science. They can be used as thermoplastic elastomers, blend compatibilizers, and interface modifiers, and are widely applied in biomedicine, construction, chemical engineering, and other fields. Linear block copolymers can be further divided into two-segment AB block copolymers, three-segment ABA block copolymers, and multi-segment block copolymers. ABA triblock copolymers typically use a flexible material as the middle segment and a rigid material as the hard segment, exhibiting the characteristics of thermoplastic elastomers. At room temperature, they exhibit rubber-like properties, while under heating conditions, they exhibit plastic-like properties.

[0003] Existing diblock or triblock polyesters are typically prepared by sequential ring-opening polymerization of different monomers. However, during the preparation of block polyesters via ring-opening polymerization, transesterification reactions occur, often leading to the generation of random sequences, which in turn affects material properties. Copolymers can be obtained through interpolymer transesterification reactions; however, the transesterification process is usually difficult to control, and the occurrence of random transesterification results in polymers that are mostly random copolymers or multiblock copolymers. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a triblock polyester material, its synthesis method, and its applications.

[0005] The technical solution of the present invention is achieved in the following ways:

[0006] One objective of this invention is to provide a method for synthesizing a triblock polyester material, the method being:

[0007] S1: Under normal pressure and inert gas protection, using organic base as catalyst and diol as transesterification agent, flexible polyester material is transesterified at a certain temperature to obtain a macromolecular polymer with hydroxyl groups at both ends.

[0008] S2: Using a macromolecular polymer with hydroxyl groups at both ends as an initiator, rigid polyester / polycarbonate materials are transesterified at a certain temperature to obtain triblock polyester.

[0009] Further specifying, the organic base in S1 is selected from one of the following structures:

[0010]

[0011] Further specified, the amount of organic alkali in S1 is 0.5–20 mol% of the flexible polyester material.

[0012] Further specifying, the diols in S1 include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-benzenedimethanol.

[0013] Further specified, the amount of glycol in S1 is 0.01–0.1 mol% of the flexible polyester material.

[0014] Further specifying, the flexible polyester material in S1 includes polycaprolactone (PCL), polybutylene adipate / terephthalate (PBAT), polybutylene terephthalate (PBT), and polyvinyl alcohol-polycaprolactone copolymer (PEO-PCL).

[0015] Further specified, the number-average molecular weight of the flexible polyester material in S1 is 10. 4 ~10 7 g / mol.

[0016] Further specified, the number-average molecular weight of the macromolecular polymers with hydroxyl groups at both ends in S1 is 2.0–15.0 kg / mol.

[0017] Further specified, the temperature in S1 is 30–200°C.

[0018] Further specifying, the rigid polyester / polycarbonate material in S2 includes polylactic acid (PLA) and bisphenol A type polycarbonate (BPA-PC).

[0019] Further specifying, the number-average molecular weight of the rigid polyester / polycarbonate material in S2 is 10. 4 ~10 7 g / mol.

[0020] Further specified, the mass ratio of initiator to rigid polyester / polycarbonate material in S2 is (0.3~3):1.

[0021] Further specified, the temperature in S2 is 30–200°C.

[0022] A second objective of this invention is to provide a triblock polyester material synthesized according to the above method.

[0023] A third objective of this invention is to provide an application of the triblock polyester material synthesized by the above method, wherein the triblock polyester material, after chain extension, is used as a thermoplastic elastomer.

[0024] The fourth objective of this invention is to provide a thermoplastic elastomer obtained by the above-mentioned application method, wherein the thermoplastic elastomer has an elongation at break greater than 800% at a tensile rate of 20 mm / min.

[0025] The fifth objective of this invention is to provide an application of the above-mentioned method in the recycling of polyester materials.

[0026] The advantages of this invention compared to the prior art are as follows:

[0027] This invention utilizes the differences in transesterification capabilities among different polymers to synthesize triblock copolymers through sequential transesterification reactions, achieving the recycling of waste polyester materials. This reduces plastic pollution caused by the large-scale use of polyester materials to a certain extent, realizes plastic recycling, and provides a method for synthesizing new materials. Specific advantages are as follows:

[0028] (1) By controlling the amount of rigid polyester / polycarbonate material added, the present invention can obtain triblock copolymers with different rigid segment mass fractions.

[0029] (2) This invention utilizes a non-metallic catalyst under mild conditions to convert polyester materials into new polymeric materials, without producing metal residues, thus achieving polymer recycling and conforming to the principles of sustainable development. Furthermore, it provides new ideas for polyester recycling and the synthesis of new materials, and is applicable to the recycling and reuse of polyester products.

[0030] (3) The triblock copolymer obtained by the sequential transesterification strategy adopted in this invention can be used as a thermoplastic elastomer after chain extension.

[0031] (4) The sequential transesterification strategy used in this invention is more controllable than random transesterification. By controlling the molecular weight and percentage of each block, the molecular weight of the obtained triblock polymer can be precisely controlled, thereby regulating the mechanical properties of the polymer. This provides an original method for synthesizing block copolymers. Attached Figure Description

[0032] Figure 1 The 1H NMR spectrum of the macromolecular initiator in step (1) of Example 2;

[0033] Figure 2 The image shows the 1H NMR spectrum of the block copolymer in step (2) of Example 2. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0035] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0037] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0038] Example 1:

[0039]

[0040] (1) The experimental procedure is as shown above, specifically including the following steps:

[0041] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n =31.7 kg / mol, PDI = 1.64), then add 139 mg of TBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 627 mg of terephthalic acid. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight is determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator is 2.4 kg / mol, and PDI = 1.58.

[0042] (2) Add 11.4g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is tested by gel permeation chromatography. The molecular weight of the block copolymer is 6.0kg / mol and PDI = 1.58.

[0043] Example 2:

[0044]

[0045] (1) The experimental procedure is as shown above, specifically including the following steps:

[0046] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n=31.7 kg / mol, PDI = 1.64), then add 139 mg of TBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 394 mg of terephthalic acid. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight is determined by gel permeation chromatography. The number average molecular weight of the macromolecular initiator is 4.9 kg / mol, and PDI = 1.64.

[0047] (2) Add 5.7g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is tested by gel permeation chromatography. The molecular weight of the block copolymer is 10.1kg / mol and PDI = 1.54.

[0048] Example 3:

[0049]

[0050] (1) The experimental procedure is as shown above, specifically including the following steps:

[0051] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n =31.7 kg / mol, PDI = 1.64), then add 139 mg of TBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 197 mg of terephthalic acid. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight is determined by gel permeation chromatography. The number average molecular weight of the macromolecular initiator is 7.3 kg / mol, and PDI = 1.65.

[0052] (2) Add 11.4g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is tested by gel permeation chromatography. The molecular weight of the block copolymer is 16.1kg / mol and PDI = 1.71.

[0053] Example 4:

[0054]

[0055] (1) The experimental procedure is as shown above, specifically including the following steps:

[0056] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n =31.7 kg / mol, PDI = 1.64), then add 139 mg of TBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 197 mg of terephthalic acid. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight is determined by gel permeation chromatography. The number average molecular weight of the macromolecular initiator is 7.3 kg / mol, and PDI = 1.65.

[0057] (2) Add 5.7g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is tested by gel permeation chromatography. The molecular weight of the block copolymer is 16.1kg / mol and PDI = 1.71.

[0058] Example 5:

[0059]

[0060] (1) The experimental procedure is as shown above, specifically including the following steps:

[0061] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n =31.7 kg / mol, PDI = 1.64), then add 139 mg of TBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 197 mg of terephthalic acid. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight is determined by gel permeation chromatography. The number average molecular weight of the macromolecular initiator is 7.3 kg / mol, and PDI = 1.65.

[0062] (2) Add 22.8g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is tested by gel permeation chromatography. The molecular weight of the block copolymer is 23.3kg / mol and PDI = 1.67.

[0063] Example 6:

[0064]

[0065] The experimental procedure is shown above, and specifically includes the following steps:

[0066] Take a 10mL Schlenk flask, heat it under vacuum and purge it with argon, then add 1.14g of poly(ε-caprolactone) (M) in a glove box. n =10.7 kg / mol, PDI = 1.59), then add 13.9 mg of TBD catalyst, 5 mL of xylene solvent, and outside the glove box, add 43 μL of 1,4-butanediol. Stir the reaction at 200 °C. After reacting for 10 min, the molecular weight is determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator is 2.9 kg / mol, and PDI = 1.88.

[0067] Example 7:

[0068]

[0069] The experimental procedure is shown above, and specifically includes the following steps:

[0070] Take a 10mL Schlenk flask, heat it under vacuum and purge it with argon, then add 1.14g of poly(ε-caprolactone) (M) in a glove box. n =34.6 kg / mol, PDI = 2.25), then add 13.9 mg of TBD catalyst, 5 mL of ethylbenzene solvent, and 14 μL of ethylene glycol outside the glove box. Stir the reaction at 80 °C. After 2 h of reaction, the molecular weight was determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator was 3.8 kg / mol, and PDI = 1.75.

[0071] Example 8:

[0072]

[0073] The experimental procedure is shown above, and specifically includes the following steps:

[0074] Take a 10mL Schlenk flask, heat it under vacuum and purge it with argon, then add 1.14g of poly(ε-caprolactone) (M) in a glove box. n =43.2 kg / mol, PDI = 1.72), then 276 mg of DBU catalyst and 5 mL of tetrahydrofuran solvent were added. Outside the glove box, 36 μL of 1,3-propanediol was added, and the reaction was stirred at 30 °C. After 72 h of reaction, the molecular weight was determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator was 2.59 kg / mol, and the PDI was 2.235.

[0075] Example 9:

[0076] (1) The experimental procedure is as shown above, specifically including the following steps:

[0077] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then place it in a glove box and add 11.4g of PBAT (M n =45.6 kg / mol, PDI = 1.86), then add 153 mg of MTBD catalyst, 50 mL of toluene solvent, and outside the glove box, add 197 mg of terephthalic acid. Stir the reaction at 80 °C. After 5 h of reaction, the molecular weight is determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator is 6.4 kg / mol, and PDI = 1.69.

[0078] (2) Add 5.7g of polylactic acid to step (1), stir and react at 130℃. After reacting for 5h, the molecular weight is determined by gel permeation chromatography. The molecular weight of the block copolymer is 9.0kg / mol and PDI = 1.53.

[0079] Example 10:

[0080]

[0081] The experimental procedure is shown above, and specifically includes the following steps:

[0082] Take a 100mL Schlenk flask, heat it under vacuum and purge it with argon, then add 11.4g of poly(ε-caprolactone) (M) in a glove box. n =31.7 kg / mol, PDI = 1.64), then add 122 mg of DMAP catalyst, 50 mL of toluene solvent, and outside the glove box, add 197 mg of terephthalic acid. Stir the reaction at 80 °C. After reacting for 10 h, the molecular weight is determined by gel permeation chromatography. The number-average molecular weight of the macromolecular initiator is 7.2 kg / mol, and PDI = 1.71.

[0083] Application Example 1: Chain extension of triblock copolymers.

[0084] 400 mg of stannous octoate and 200 μL of hexamethylene diisocyanate were added to 10 g of the triblock copolymer obtained in Example 2. The mixture was stirred at 80 °C for 1 h to obtain a polymer with a molecular weight of 51.6 kg / mol and a PDI of 2.39.

[0085] Application Example 2: Chain extension of triblock copolymers.

[0086] 400 mg of stannous octoate and 100 μL of hexamethylene diisocyanate were added to 10 g of the triblock copolymer obtained in Example 4. The mixture was stirred at 80 °C for 1 h to obtain a polymer with a molecular weight of 56.7 kg / mol and a PDI of 2.09.

[0087] Application Example 3: Chain extension of triblock copolymers.

[0088] 400 mg of stannous octoate and 100 μL of hexamethylene diisocyanate were added to 10 g of the triblock copolymer obtained in Example 9. The mixture was stirred at 80 °C for 1 h to obtain a polymer with a molecular weight of 55.4 kg / mol and a PDI of 2.18.

[0089] Example of results:

[0090] (1) Sample preparation: The material of Application Examples 1-3 was placed in a mold with a length of 105mm, a width of 35mm, and a thickness of 1mm, and the material was hot-pressed at 100℃ to obtain a rectangular sample.

[0091] (2) Performance Testing: The specimens were cut into dumbbell shapes using a standard-sized cutter on a sample preparation machine. Tensile properties were then tested using a universal tensile testing machine with tensile clamps. Tensile rate: 20 mm / min. The test results are shown in Table 1 below.

[0092] Table 1

[0093] Tensile strength / MPa 9.7 17.6 10.8 Elongation at break / % 1189 877 1076

[0094] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for synthesizing a triblock polyester material, characterized in that: S1: Under normal pressure and inert gas protection, using an organic base as a catalyst and a glycol as a transesterification agent, flexible polyester material is transesterified at a certain temperature to obtain a macromolecular polymer with hydroxyl groups at both ends; the flexible polyester material is PCL or PBAT. S2: Using a macromolecular polymer with hydroxyl groups at both ends as an initiator, a rigid polyester / polycarbonate material is transesterified at a certain temperature to obtain a triblock polyester; the rigid polyester / polycarbonate material is PLA.

2. The method according to claim 1, characterized in that, The organic base in S1 is selected from one of the following structures: The amount of organic alkali used is 0.5~20 mol of flexible polyester material.

3. The method according to claim 1, characterized in that, The diols in S1 include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-benzenedimethanol, with the amount of diols used being 0.01~0.1 mol of the flexible polyester material.

4. The method according to claim 1, characterized in that, The number-average molecular weight of the flexible polyester material in S1 is 10. 4 ~10 7 g / mol.

5. The method according to claim 1, characterized in that, The number-average molecular weight of S1 macromolecules with hydroxyl groups at both ends is 2.0~15.0 kg / mol, and the temperature is 30~200℃.

6. The method according to claim 1, characterized in that, The number-average molecular weight of the rigid polyester / polycarbonate material in S2 is 10. 4 ~10 7 g / mol, the mass ratio of initiator to rigid polyester / polycarbonate material is (0.3~3):1, and the temperature is 30~200℃.

7. The application of the method according to any one of claims 1-6 in the recycling of polyester materials.

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