Weather-resistant and wear-resistant aliphatic thermoplastic elastomer with star-shaped structure and preparation method thereof
By designing star-shaped polyols containing five- or six-membered rings to synthesize aliphatic thermoplastic elastomers, the problems of aging and mechanical property degradation of traditional thermoplastic elastomers in outdoor environments have been solved. High tensile strength, wear resistance and biodegradability have been achieved, making them suitable for biodegradable materials and flexible electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN BEST ADVANCED MATERIALS CO LTD
- Filing Date
- 2026-02-05
- Publication Date
- 2026-05-15
AI Technical Summary
Existing thermoplastic elastomers are prone to aging in outdoor environments, resulting in a decline in mechanical properties and an inability to meet the combined requirements of high tensile strength and high elastic recovery. Meanwhile, traditional petroleum-based materials are non-degradable, have significant environmental shortcomings, and exhibit poor wear resistance.
Novel star-shaped polyols containing five- or six-membered rings were designed to synthesize aliphatic thermoplastic elastomers with star-shaped structures. Using poly-L-lactide and polycaprolactone as chain segments, aliphatic thermoplastic elastomers with high tensile strength and high elongation at break were prepared by ring-opening polymerization.
It achieves synergistic optimization of high tensile strength and high elongation at break, improves wear resistance and weather resistance, and the material is renewable and degradable, making it suitable for biodegradable materials and flexible electronic devices.
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Abstract
Description
Technical Field
[0001] This application belongs to the field of thermoplastic elastomer technology, and specifically relates to a star-shaped polyol, its preparation method and application, as well as a star-shaped aliphatic thermoplastic elastomer, its preparation method and application. Background Technology
[0002] Thermoplastic elastomers (TPEs), as a fusion material of plastics and rubber, combine the advantages of room-temperature elasticity and high-temperature processability, and are widely used in the automotive, electronics, and photovoltaic industries, with current market demand continuing to surge. However, traditional commercial TPEs are mainly petroleum-based materials, especially styrene-based thermoplastic elastomers, such as SIS and SBS, which contain styrene segments. These petroleum-based thermoplastic elastomers have environmental drawbacks due to their non-degradability and reliance on fossil resources, conflicting with the current trend of carbon reduction and circular economy. Moreover, styrene-based thermoplastic elastomers contain benzene rings and unsaturated double bonds, making them prone to aging under outdoor environments (light, oxygen, heat, humidity), manifesting as surface cracking, powdering, yellowing, and decreased mechanical properties, failing to meet the requirements of outdoor applications. On the other hand, for downstream high-end applications, such as lightweight automotive components and electronic protective materials, the mechanical performance requirements of thermoplastic elastomers are constantly increasing, requiring a combination of high tensile strength and high elastic recovery.
[0003] Sustainable thermoplastic elastomers based on aliphatic polyesters have been developed, with poly(L-lactide) (PLLA, hard segment) and polycaprolactone (PCL, soft segment) as core components. They possess renewable and biodegradable properties. However, thermoplastic aliphatic polyesters with an ABA linear triblock structure have significant drawbacks. The most important is insufficient mechanical balance, making it difficult to simultaneously achieve synergistic optimization of high tensile strength and high elongation at break. They also have poor abrasion resistance, limiting their application areas. Furthermore, they have poor weather resistance, easily exhibiting permanent deformation and long-term degradation of mechanical properties under ultraviolet radiation and in humid and hot environments. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this application designs a novel polyol structure containing at least one five- or six-membered ring. Using this as the core, a star-shaped aliphatic thermoplastic elastomer is further synthesized, thereby achieving synergistic optimization of high tensile strength and high elongation at break, improving wear resistance and weather resistance. At the same time, poly-L-lactide and polycaprolactone are used. These cyclic lactones are both biomass-derived, do not rely on petroleum resources, and have the characteristics of being both renewable and biodegradable.
[0005] To achieve the above technical objectives, the technical solution adopted in this application is as follows: Firstly, a star-shaped polyol, wherein each molecule of the star-shaped polyol contains at least 6 hydroxyl groups and the molecular center contains at least one five-membered or six-membered ring structure. The five-membered ring or six-membered ring is selected from a pure hydrocarbon ring or a heterocycle with at least one heteroatom; Preferably, the heteroatom is selected from any one or more of N, O, and S; Preferably, the heteroatom is selected from any one or both of N and O; Preferably, the star-shaped polyol comprises any one of an imidazolidinedione ring, an isocyanurate ring, or cyclohexane; Preferably, each molecule of the star-shaped polyol contains 6-9 hydroxyl groups.
[0006] Secondly, the method for preparing the star-shaped polyol described above involves reacting a compound containing at least two epoxy groups and at least one five-membered or six-membered ring structure with diethanolamine as a raw material. Preferably, the five-membered or six-membered ring is selected from a pure hydrocarbon ring or a heterocycle with at least one heteroatom; Preferably, the heteroatom is selected from any one or more of N, O, and S; Preferably, the heteroatom is selected from any one or both of N and O; Preferably, the five-membered or six-membered ring is selected from any one of imidazolidinedione ring, isocyanurate ring, or cyclohexane; Preferably, after the reaction is complete, excess diethanolamine is removed by vacuum distillation; Preferably, the compound comprising at least two epoxy groups and at least one five-membered or six-membered ring structure is selected from any one of 5,5-dimethyl-1,3-bis(ethylene oxide-2-ylmethyl)imidazolidine-2,4-dione, triglycidyl isocyanurate, or diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylic acid. Preferably, the reaction includes carrying out the reaction at a controlled temperature of 60-120°C; Preferably, the reaction is terminated after detecting the characteristic absorption peak of the epoxy group by infrared spectroscopy for one hour.
[0007] Thirdly, the use of the aforementioned star-shaped polyols as raw materials in the synthesis of aliphatic thermoplastic elastomers.
[0008] Fourthly, an aliphatic thermoplastic elastomer with a star-shaped structure is obtained by first ring-opening polymerization of a first cyclic lactone with the aforementioned star-shaped polyol as an initiator in the presence of an organometallic catalyst, and then ring-opening polymerization of a second cyclic lactone in the presence of an organic base catalyst. In each arm of the star-shaped aliphatic thermoplastic elastomer, the ratio of the number of repeating units of the first cyclic lactone segment to the number of repeating units of the second cyclic lactone segment is (0.5-2):1. Preferably, in each arm of the star-shaped aliphatic thermoplastic elastomer, the ratio of the number of repeating units of the first cyclic lactone segment to the number of repeating units of the second cyclic lactone segment is (1-2):1; Preferably, the organometallic catalyst is selected from organotin catalysts; More preferably, the organometallic catalyst is selected from stannous octoate; Preferably, the organic base catalyst is selected from organic base catalysts containing tertiary amines; More preferably, the organic base catalyst is selected from 1,8-diazabicyclo[5.4.0]undec-7-ene; Preferably, the first cyclic lactone is selected from a monoester group of cyclic esters; More preferably, the first cyclic lactone is selected from any one of butyrolactone, valproic acid lactone and caprolactone, which are either unsubstituted or substituted with at least one C1-C4 alkyl group; More preferably, the first cyclic lactone is selected from either ε-caprolactone or methyl-ε-caprolactone; More preferably, the first cyclic lactone is selected from one or more C1-C4 alkyl-substituted caprolactones; Preferably, the second cyclic lactone is selected from diester-based cyclic esters; More preferably, the second cyclic lactone is selected from any one of glycolide and lactide, either unsubstituted or substituted with at least one C1-C4 alkyl group.
[0009] Preferably, the second cyclic lactone is selected from any one of L-lactide, D-lactide, or racemic lactide.
[0010] Preferably, the average degree of polymerization of the first cyclic lactone segment after ring opening is 5-20; Preferably, the average degree of polymerization of the second cyclic lactone segment after ring opening is 5-15.
[0011] Fifthly, the preparation method of the star-shaped aliphatic thermoplastic elastomer described above specifically includes... S1. Under the protection of an inert gas, star-shaped polyols and first cyclic lactones undergo ring-opening polymerization in the presence of an organometallic catalyst to obtain the corresponding star-shaped polymers. S2. Under the protection of an inert gas, the star-shaped polymer obtained in step S1 and the second cyclic lactone are subjected to ring-opening polymerization in the presence of an organic base catalyst to obtain the corresponding star-shaped aliphatic thermoplastic elastomer. S3. Dissolve the star-shaped aliphatic thermoplastic elastomer obtained in step S2 in the first solvent, add it to the second solvent to precipitate, and obtain the purified star-shaped aliphatic thermoplastic elastomer by filtration, washing and drying.
[0012] The ring-opening polymerization temperature in step S1 is 80-160℃; Preferably, the molar ratio of the hydroxyl group to the first cyclic lactone in the star-shaped polyol is 1:(5-20); More preferably, the molar ratio of the hydroxyl group to the first cyclic lactone in the star-shaped polyol is 1:(10-15); Preferably, the molar amount of the organometallic catalyst is 1-3 mol% of the molar amount of the first cyclic lactone. The ring-opening polymerization temperature in step S2 is from room temperature to 60°C; Preferably, the molar ratio of the hydroxyl group to the second cyclic lactone in the star-shaped polyol is 1:(5-15); More preferably, the molar ratio of the hydroxyl group to the second cyclic lactone in the star-shaped polyol is 1:(10-13); Preferably, the molar amount of the organic base catalyst is 1-3 mol% of the molar amount of the second cyclic lactone. The first solvent is selected from one or both of dichloromethane and tetrahydrofuran; The second solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, acetonitrile, acetone and N,N-dimethylformamide.
[0013] Sixthly, the application of the star-shaped aliphatic thermoplastic elastomers described above in the preparation of biodegradable materials, flexible electronic devices, or elastomer materials.
[0014] The beneficial effects of the technical solution proposed in this application are as follows: First, a novel polyol structure was designed and synthesized using multi-arm epoxy compounds as raw materials. Each molecule of the polyol contains at least one five- or six-membered ring. Using this as the core, a star-shaped aliphatic thermoplastic elastomer was further synthesized, thereby achieving synergistic optimization of high tensile strength and high elongation at break, improving wear resistance and weather resistance. The five- or six-membered ring at the center of the star-shaped aliphatic thermoplastic elastomer molecule has the characteristics of high rigidity and low rotational freedom, which can distribute tensile stress to each side arm and reduce irreversible slippage of the molecular chain. Simultaneously, poly(L-lactide) and polycaprolactone were used as block segments. These cyclic lactones are all biomass-derived, do not rely on petroleum resources, and have both renewable and biodegradable characteristics. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 Example 4: Preparation of a star-shaped aliphatic thermoplastic elastomer 1 H-NMR spectra. (a) shows the chemical shifts of the hydrogen atoms on the dimethyl group in the core 5,5-dimethyl-1,3-bis(ethyleneoxy-2-ylmethyl)imidazolidine-2,4-dione; (b) shows the chemical shifts of the hydrogen atoms on the methyl group in the PLLA segment of the side arm; and (c) shows the chemical shifts of the -(C=O)-C segment of the PCL segment in the side arm. H Chemical shifts of hydrogen atoms on the methylene group of 2-, (d) represents the -C segment of the PCL chain in the side arm. H Chemical shift of the hydrogen atom on the methylene group in 2-O-, (e) is the terminal -(C=O)-(CH-CH3)-O of the PLLA chain segment. H Chemical shift of the hydrogen atom on the hydroxyl group, (f) is the PLLA segment in the side arm -(C=O)-(C H Chemical shift of hydrogen atoms on the methine group of (CH3)-O-. Detailed Implementation
[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. It should be noted that the terminology used herein is only for describing specific implementation methods and is not intended to limit the exemplary implementation methods according to the present invention.
[0018] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings: The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").
[0019] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.
[0020] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.
[0021] In this application, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions containing the listed features.
[0022] Unless otherwise specified, the experimental conditions used in the examples are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the examples can be purchased commercially.
[0023] Example 1
[0024] Using 5,5-dimethyl-1,3-bis(ethylene oxide-2-ylmethyl)imidazolidine-2,4-dione as the starting material, 48 g (0.2 mol) of 5,5-dimethyl-1,3-bis(ethylene oxide-2-ylmethyl)imidazolidine-2,4-dione and 52.6 g (0.5 mol) of diethanolamine were added to a three-necked flask. The reaction was carried out at 90 °C for 8 hours. The absorption peak of the epoxy group at 910-920 cm⁻¹ disappeared as detected by infrared spectroscopy. Unreacted diethanolamine was then removed by vacuum distillation (760 mmHg) at 90 °C to obtain a 6-arm star-shaped polyol.
[0025] Structural confirmation 1 H-NMR (CDCl3): δ1.19-1.29 (6H, m), 2.81-3.02 (12H, m), 3.39-3.62 (10H,m), 3.76(6H,s), 3.87-4.09(4H, m).
[0026] Therefore, its structure is confirmed as follows: ; Example 2
[0027] Using triglycidyl isocyanurate as the initial raw material, 59.5 g (0.2 mol) of triglycidyl isocyanurate and 84 g (0.8 mol) of diethanolamine were added to a three-necked flask and reacted at 110 °C for 8 hours. The absorption peak of the epoxy group at 910-920 cm⁻¹ disappeared as detected by infrared spectroscopy. Unreacted diethanolamine was then removed by vacuum distillation (760 mmHg) at 90 °C to obtain a 9-arm star-shaped polyol.
[0028] Structural confirmation 1 H-NMR (CDCl3): δ2.81-2.97 (18H, m), 3.50-3.62 (12H,m), 3.78(9H,s), 3.85-4.00(9H, m).
[0029] Therefore, its structure is confirmed as follows: ; Example 3
[0030] Using 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester as the starting material, 57.9 g (0.2 mol) of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester and 84 g (0.8 mol) of diethanolamine were added to a three-necked flask. The flask temperature was controlled at 80 °C and the reaction was carried out for 8 hours. The absorption peak of the epoxy group at 910-920 cm⁻¹ disappeared by infrared spectroscopy. Then, the unreacted diethanolamine was removed by vacuum distillation (760 mmHg) at 90 °C to obtain a 9-arm star-shaped polyol.
[0031] Structural confirmation 1 H-NMR (CDCl3): δ 1.65-1.87 (2H, m), 2.12 (1H, ddd, J = 14.42, 10.26, 2.79 Hz), 2.34 (1H, ddd, J = 14.42, 2.79, 2.79 Hz), 2.62-2.97 (17H, m), 3.13(1H, ddd, J = 10.26, 2.79, 2.79 Hz), 3.30 (1H, ddd, J = 2.79, 2.79, 2.79 Hz),3.44-3.63 (13H, m), 3.77(9H,s),3.90 (2H, dddd, J = 7.11, 7.11, 3.30, 3.30Hz), 4.55 (4H, d, J = 7.11 Hz).
[0032] Therefore, its structure is confirmed as follows: ; Example 4
[0033] The synthesis of a star-shaped aliphatic thermoplastic elastomer was based on the 6-arm star-shaped polyol prepared in Example 1. The average degree of polymerization of the ε-caprolactone (PCL) segment in the side arms was designed to be 10, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10.
[0034] Synthesis steps: Under nitrogen protection, 13.5 g (0.03 mol) of the 6-arm star-shaped polyol prepared in Example 1 and 205.5 g (1.8 mol) of ε-caprolactone (PCL) were added to a pre-dehydrated and deoxygenated reaction vessel. After stirring, the temperature was raised to 100 °C, and 10.2 g (0.025 mol) of stannous octoate dissolved in 20 mL of toluene was added. The reaction vessel was sealed and reacted at 120 °C for 24 hours. After the reaction was completed, the temperature was lowered to room temperature, and 259.4 g (1.8 mol) of L-lactide (PLLA) dissolved in 100 mL of dichloromethane and 5.48 g of catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added. The reaction was stopped after stirring at room temperature for 2 hours.
[0035] After the reaction was completed, the reaction mixture was dissolved in 100 mL of dichloromethane to obtain a dichloromethane solution of a star-shaped aliphatic thermoplastic elastomer. The solution was added dropwise to 300 mL of methanol to precipitate the star-shaped aliphatic thermoplastic elastomer. The precipitate was collected by filtration and washed three times with methanol to remove residual monomers, catalysts and oligomer impurities.
[0036] The washed polymer was placed in a vacuum drying oven and dried at 60°C for 24 hours to obtain the final star-shaped aliphatic thermoplastic elastomer.
[0037] For the aliphatic thermoplastic elastomer with a star-shaped structure prepared in Example 4 1 H-NMR spectrum as shown Figure 1 As shown, (a) represents the chemical shift of the hydrogen atom on the dimethyl group in the core 5,5-dimethyl-1,3-bis(ethyleneoxy-2-ylmethyl)imidazolidine-2,4-dione, (b) represents the chemical shift of the hydrogen atom on the methyl group in the PLLA segment of the side arm, and (c) represents the chemical shift of the -(C=O)-C segment of the PCL segment in the side arm. H Chemical shifts of hydrogen atoms on the methylene group of 2-, (d) represents the -C segment of the PCL chain in the side arm. H Chemical shift of the hydrogen atom on the methylene group in 2-O-, (e) is the terminal -(C=O)-(CH-CH3)-O of the PLLA chain segment. H Chemical shift of the hydrogen atom on the hydroxyl group, (f) is the PLLA segment in the side arm -(C=O)-(C H The chemical shift of the hydrogen atom on the methine of (-CH3)-O- confirms that the PCL and PLLA segments were grafted onto the 6-arm star-shaped polyol core prepared in Example 1.
[0038] Example 5
[0039] The synthesis method and steps were the same as in Example 4, except that the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10. The amount of PCL used was 308.17 g (2.7 mol), corresponding to 15.3 g of stannous octoate catalyst; the amount of PLLA used was 259.4 g (1.8 mol), corresponding to 5.48 g of DBU catalyst.
[0040] Example 6
[0041] The synthesis method and steps were the same as in Example 4, except that the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 12.5. The amount of PCL used was 308.17 g (2.7 mol), corresponding to a catalyst amount of 15.3 g of stannous octoate; the amount of PLLA used was 324.3 g (2.25 mol), corresponding to a catalyst amount of 6.85 g of DBU.
[0042] Example 7
[0043] The synthesis of a star-shaped aliphatic thermoplastic elastomer was based on the 9-arm star-shaped polyol prepared in Example 2. The average degree of polymerization of the ε-caprolactone (PCL) segment in the side arms was designed to be 10, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10.
[0044] Synthesis steps: Under nitrogen protection, 12.3 g (0.02 mol) of the 9-arm star-shaped polyol prepared in Example 2 and 205.5 g (1.8 mol) of ε-caprolactone (PCL) were added to a pre-dehydrated and deoxygenated reaction vessel. After stirring, the temperature was raised to 100 °C, and 10.2 g (0.025 mol) of stannous octoate dissolved in 20 mL of toluene was added. The reaction vessel was sealed and reacted at 120 °C for 24 hours. After the reaction was completed, the temperature was lowered to room temperature, and 259.4 g (1.8 mol) of L-lactide (PLLA) dissolved in 100 mL of dichloromethane and 5.48 g of catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added. The reaction was stopped after stirring at room temperature for 2 hours.
[0045] After the reaction was completed, the reaction mixture was dissolved in 100 mL of dichloromethane to obtain a dichloromethane solution of a star-shaped aliphatic thermoplastic elastomer. The solution was added dropwise to 300 mL of methanol to precipitate the star-shaped aliphatic thermoplastic elastomer. The precipitate was collected by filtration and washed three times with methanol to remove residual monomers, catalysts and oligomer impurities.
[0046] The washed polymer was placed in a vacuum drying oven and dried at 50°C for 24 hours to obtain the final star-shaped aliphatic thermoplastic elastomer.
[0047] Example 8
[0048] The synthesis method and steps were the same as in Example 7, except that the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10. The amount of PCL used was 308.17 g (2.7 mol), corresponding to 15.3 g of stannous octoate catalyst; the amount of PLLA used was 259.4 g (1.8 mol), corresponding to 5.48 g of DBU catalyst.
[0049] Example 9
[0050] The synthesis method and steps were the same as in Example 7, except that the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 12.5. The amount of PCL used was 308.17 g (2.7 mol), corresponding to 15.3 g of stannous octoate catalyst; the amount of PLLA used was 324.3 g (2.25 mol), corresponding to 6.85 g of DBU catalyst.
[0051] Example 10
[0052] Using the 9-arm star-shaped polyol prepared in Example 3 as the core, the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arms was designed to be 10, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10. The synthesis method and steps were the same as in Example 7, except that the amount of the 9-arm star-shaped polyol prepared in Example 3 was 12.6 g (0.02 mol), the amount of PCL was 205.5 g (1.8 mol), the corresponding amount of stannous octoate catalyst was 10.2 g, the amount of PLLA was 259.4 g (1.8 mol), and the corresponding amount of DBU catalyst was 5.48 g.
[0053] Example 11
[0054] Using the 9-arm star-shaped polyol prepared in Example 3 as the core, the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arms was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment to be 10. The synthesis method and steps were the same as in Example 10, except that the amount of PCL used was 308.17 g (2.7 mol), the corresponding amount of stannous octoate catalyst was 15.3 g, the amount of PLLA used was 259.4 g (1.8 mol), and the corresponding amount of DBU catalyst was 5.48 g.
[0055] Example 12
[0056] Using the 9-arm star-shaped polyol prepared in Example 3 as the core, the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arms was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment to be 12.5. The synthesis method and steps were the same as in Example 10, except that the amount of PCL used was 308.17 g (2.7 mol), the corresponding amount of stannous octoate catalyst was 15.3 g, the amount of PLLA used was 324.3 g (2.25 mol), and the corresponding amount of DBU catalyst was 6.85 g.
[0057] Comparative Example 1 Using 6-hydroxy dipentaerythritol as the core, the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10. The synthesis method and steps were the same as in Example 3, except that the amount of dipentaerythritol used was 7.7 g (0.03 mol), the amount of PCL used was 308.17 g (2.7 mol), the corresponding amount of stannous octoate catalyst was 15.3 g, the amount of PLLA used was 259.4 g (1.8 mol), and the corresponding amount of DBU catalyst was 5.48 g.
[0058] Comparative Example 2 Using 6-hydroxy dipentaerythritol as the core, the average degree of polymerization of the ε-caprolactone (PCL) segment in the side arm was designed to be 15, and the average degree of polymerization of the L-lactide (PLLA) segment was designed to be 10. The synthesis method and steps were the same as in Example 10, except that the amount of PCL used was 308.17 g (2.7 mol), the corresponding amount of stannous octoate catalyst was 15.3 g, the amount of PLLA used was 324.3 g (2.25 mol), and the corresponding amount of DBU catalyst was 6.85 g.
[0059] Performance testing The purified and dried aliphatic thermoplastic elastomers with star-shaped structures prepared in Examples 4-12 and Comparative Examples 1-2 were melted at 180°C, and 0.5 wt% of the hindered phenolic antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.5 wt% of the phosphite antioxidant tris(nonylphenyl) phosphite, and 0.5 wt% of the ultraviolet absorber 2-hydroxy-4-n-octyloxybenzophenone were added. The mixture was then pressed into thin sheets, rapidly quenched, and cut into dumbbell-shaped samples or other shapes required by the test standard for later use. The samples were aged at room temperature for 24 hours before performance testing.
[0060] Mechanical property testing: Referring to the ISO 527 standard, dumbbell-shaped specimens were stretched to fracture at a rate of 50 mm / min. The tensile strength and elongation at fracture were recorded. The tensile toughness was obtained by calculating the area under the stress-strain curve.
[0061] Abrasion resistance test: Refer to ISO 4649-2024 Method A. The abrasion resistance of the material is quantitatively characterized by measuring the volume of wear loss of the sample under standard conditions. Test conditions: load 10N, grinding wheel speed 100r / min.
[0062] For the aging resistance test, referring to the standard GB / T14522-2008, a UVA-340 fluorescent ultraviolet lamp with a wavelength of 340nm was used. The exposure period was 8 hours of drying and 4 hours of condensation. After 1000 hours of cycling, the tensile strength at break and the elongation at break were tested, and their change rates were recorded.
[0063] The test results are recorded in Table 1.
[0064] Table 1
[0065] Analysis of the data in Table 1 shows that the aliphatic thermoplastic elastomers with star-shaped structures synthesized using the 6-9 arm star-shaped polyols prepared in Examples 1-3 as the core (Examples 4-12) have better mechanical properties and wear resistance. After 1000 hours of aging, the changes in tensile strength at break and elongation at break do not exceed 3.5%, indicating better weather resistance. Comparative Examples 1-2, using dipentaerythritol as the core, synthesized aliphatic thermoplastic elastomers with star-shaped structures, exhibited inferior mechanical properties, wear resistance, and weather resistance compared to Examples 4-12. This indicates that the core structure of the star-shaped aliphatic thermoplastic elastomer is crucial, and the star-shaped core structure significantly affects its mechanical properties, wear resistance, and weather resistance.
[0066] Among them, the star-shaped aliphatic thermoplastic elastomers of Examples 4-12 exhibit a superior strength-toughness balance, providing higher strength load-bearing capacity while maintaining high elasticity. Their core contains either a five- or six-membered ring. Whether it is a pure hydrocarbon alicyclic group or a hybrid with -N- (C=O)-, it exhibits characteristics of minimal conformational changes in the ring structure, high rigidity, and low rotational freedom. Its rigidity effectively distributes tensile stress across the arms and reduces irreversible slippage of the molecular chains in the initial stage of stress. Simultaneously, the multiple star-shaped side arms provide deformation capacity, thus exhibiting high wear resistance, high tensile strength at break, and high elongation at break.
[0067] On the other hand, after 1000 hours of ultraviolet aging, both Examples 4-12 and Comparative Examples 1-2 showed a decrease in tensile strength at break and an increase in elongation at break, indicating that the materials underwent an aging process mainly characterized by degradation. The mechanical properties changed from "strong and hard" to "weak and tough" due to the breakage of some molecular chains. The aliphatic thermoplastic elastomers with star-shaped structures synthesized using the 6-9 arm star-shaped polyols prepared in Examples 1-3 as the core have a stronger resistance to degradation. This is manifested in the smaller change rate of tensile strength and elongation at break of the degraded aliphatic thermoplastic elastomers with star-shaped structures, thus exhibiting better weather resistance.
[0068] Finally, it should be noted that the above-described embodiments are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.
Claims
1. A star-shaped polyol, characterized in that, Each molecule of its star-shaped polyol contains at least 6 hydroxyl groups and at least one five- or six-membered ring structure at the center of the molecule. The five-membered ring or six-membered ring is selected from a pure hydrocarbon ring or a heterocycle with at least one heteroatom.
2. A method for preparing a star-shaped polyol as described in claim 1, characterized in that, It is obtained by reacting a compound containing at least two epoxy groups and at least one five-membered or six-membered ring structure with diethanolamine.
3. The method for preparing the star-shaped polyol according to claim 2, characterized in that, The compound containing at least two epoxy groups and at least one five-membered or six-membered ring structure is selected from any one of 5,5-dimethyl-1,3-bis(ethylene oxide-2-ylmethyl)imidazolidine-2,4-dione, triglycidyl isocyanurate, or diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylic acid.
4. The use of the star-shaped polyol as described in claim 1 as a raw material in the synthesis of aliphatic thermoplastic elastomers.
5. A star-shaped aliphatic thermoplastic elastomer, characterized in that, Using the star-shaped polyol as described in claim 1 as an initiator, the product is first subjected to ring-opening polymerization with a first cyclic lactone in the presence of an organometallic catalyst, and then subjected to ring-opening polymerization with a second cyclic lactone in the presence of an organic base catalyst. In each arm of the star-shaped aliphatic thermoplastic elastomer, the ratio of the number of repeating units of the first cyclic lactone segment to the number of repeating units of the second cyclic lactone segment is (0.5-2):
1.
6. The aliphatic thermoplastic elastomer with a star-shaped structure according to claim 5, characterized in that, The organometallic catalyst is selected from organotin catalysts; And / or, the organic base catalyst is selected from organic base catalysts containing tertiary amines.
7. The aliphatic thermoplastic elastomer with a star-shaped structure according to claim 5, characterized in that, The first cyclic lactone is selected from a monoester-based cyclic ester; And / or, the second cyclic lactone is selected from diester-based cyclic esters; And / or, the average degree of polymerization of the first cyclic lactone segment after ring opening is 5-20; And / or, the average degree of polymerization of the second cyclic lactone segment after ring opening is 5-15.
8. A method for preparing an aliphatic thermoplastic elastomer with a star-shaped structure as described in any one of claims 5-7, characterized in that, The preparation methods specifically include: S1. Under the protection of an inert gas, star-shaped polyols and first cyclic lactones undergo ring-opening polymerization in the presence of an organometallic catalyst to obtain the corresponding star-shaped polymers. S2. Under the protection of an inert gas, the star-shaped polymer obtained in step S1 and the second cyclic lactone are subjected to ring-opening polymerization in the presence of an organic base catalyst to obtain the corresponding star-shaped aliphatic thermoplastic elastomer. S3. Dissolve the star-shaped aliphatic thermoplastic elastomer obtained in step S2 in the first solvent, add it to the second solvent to precipitate, and obtain the purified star-shaped aliphatic thermoplastic elastomer by filtration, washing and drying. The ring-opening polymerization temperature in step S1 is 80-160℃; The ring-opening polymerization temperature in step S2 is from room temperature to 60°C; The first solvent is selected from one or both of dichloromethane and tetrahydrofuran; The second solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, acetonitrile, acetone and N,N-dimethylformamide.
9. The method for preparing the star-shaped aliphatic thermoplastic elastomer according to claim 8, characterized in that, The molar ratio of the hydroxyl group to the first cyclic lactone in the star-shaped polyol is 1:(5-20); And / or, the molar amount of the organometallic catalyst is 1-3 mol% of the molar amount of the first cyclic lactone. And / or, the molar ratio of the hydroxyl group to the second cyclic lactone of the star-shaped polyol is 1:(5-15); And / or, the molar amount of the organic base catalyst is 1-3 mol of the molar amount of the second cyclic lactone.
10. The use of the star-shaped aliphatic thermoplastic elastomer as described in any one of claims 5-7 in the preparation of biodegradable materials, flexible electronic devices or elastomer materials.