Bio-based polyamide elastomer as well as preparation method and application thereof

Abstract

The invention discloses a bio-based polyamide elastomer as well as a preparation method and application thereof. A hard segment domain of the bio-based polyamide elastomer is formed by polymerizing aliphatic straight-chain dibasic acid and aliphatic straight-chain diamine, and a soft segment domain of the bio-based polyamide elastomer is formed by polymerizing aliphatic straight-chain dibasic acid and polyether amine. According to the preparation method, the polyamide salt solution and the polyether amine salt solution are firstly prepared respectively, then the bio-based polyamide elastomer with the hard segment domains and the soft segment domains being alternately blocked is obtained through reaction copolymerization of the two salt solutions, and through control of the soft segment domains, the bio-based polyamide elastomer has good strength and flexibility and good biocompatibility, and can be used for preparing the bio-based polyamide elastomer with the hard segment domains and the soft segment domains being alternately blocked. The problems that an existing elastomer is low in strength, poor in biocompatibility and the like are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of elastomers, and more specifically, relates to a bio-based polyamide elastomer, a preparation method thereof, and an application thereof. Background Art

[0002] Polyamide elastomers are a class of high-molecular materials with excellent performance and wide applications. While having the basic characteristics of traditional rubber and plastic elastomers, they maintain the excellent physical and mechanical properties, good thermal processing properties, and biocompatibility of polyamides. These excellent properties enable polyamide elastomers to play a key role in the field of interventional medical equipment. The properties of polyamide elastomers can be adjusted by adjusting the types and ratios of the hard segment domain and the soft segment domain. The polyamide hard segment domain has a relatively high melting temperature and glass transition temperature, and its physical cross-linking points are formed by crystallization, showing a glassy state or a crystalline state at room temperature, thereby endowing the polyamide elastomer with high strength; the amorphous polyetheramine soft segment domain makes the polyamide elastomer exhibit good flexibility. Due to the obvious performance advantages of polyamide elastomers, they are widely used in many fields such as electronics and electrical appliances, food packaging, automotive parts, sports goods, and medical treatment.

[0003] The production raw materials of commercial polyamide elastomers mostly come from non-renewable petroleum resources. In recent years, people have realized the importance of sustainable development of resource conservation and environmental protection. By using renewable biomass, such as grains, legumes, animal fur waste, etc., bio-based monomers are prepared through biological, chemical, and physical methods, and then bio-based elastomers are prepared. The development of bio-based materials not only helps to conserve limited petroleum resources but also makes a great contribution to energy conservation and emission reduction. Although bio-based polyamide elastomers meet the requirements of sustainable development and can provide good performance conditions, there are still the following deficiencies in the medical field:

[0004] (1) The antibacterial property of the elastomer is insufficient, and it is easy to be contaminated by bacteria and other microorganisms; (2) When a soft segment is introduced into the polyamide elastomer, while having good flexibility, it will cause a significant reduction in strength; (3) The biocompatibility of the polyamide elastomer still needs to be improved.

[0005] In CN116574251B, an antibacterial nylon elastomer, a preparation method thereof, and an application thereof, a polyamide hard segment is obtained by reacting a dibasic acid with a first diamine, a reactive antibacterial agent is obtained by reacting a second diamine with vanillin to form a Schiff base reaction, and then the hard segment polyamide, a polyetheramine soft segment, and the reactive antibacterial agent are subjected to a polycondensation reaction to obtain an antibacterial nylon elastomer. Although this patent improves the antibacterial property of the elastomer by adding an antibacterial agent, due to the types of elastomer raw materials and the added antioxidant additives and catalysts, it is difficult to ensure its biocompatibility and it cannot be better applied in the medical field. Summary of the Invention

[0006] In order to overcome the problems of low strength, poor biocompatibility, and complex preparation process of existing elastomers, the present invention provides a bio-based polyamide elastomer, a preparation method thereof, and an application thereof.

[0007] The present invention is achieved through the following technical solutions:

[0008] A bio-based polyamide elastomer, comprising alternately block copolymerized hard segment domains and soft segment domains, wherein the mass fraction of the hard segment domains is 80% - 95%, and the mass fraction of the soft segment domains is 5% - 20%; the hard segment domains are polymerized from aliphatic straight-chain dibasic acids and aliphatic straight-chain diamines, and the soft segment domains are polymerized from aliphatic straight-chain dibasic acids and polyetheramines; the aliphatic straight-chain dibasic acids include one or more of bio-based sebacic acid, bio-based adipic acid, and bio-based azelaic acid; the aliphatic straight-chain diamines include one or more of bio-based pentamethylenediamine, bio-based hexamethylenediamine, and bio-based sebac diamine.

[0009] Furthermore, the number average molecular weight of the polyetheramine is 600 - 900.

[0010] A preparation method of a bio-based polyamide elastomer, the steps comprising:

[0011] S1. Prepare a polyamide salt solution;

[0012] Heat and react an aliphatic straight-chain dibasic acid, an aliphatic straight-chain diamine, and deionized water to obtain a polyamide salt solution;

[0013] S2. Prepare a polyetheramine salt solution;

[0014] Heat and react a polyetheramine, an aliphatic straight-chain dibasic acid, and deionized water to obtain a polyetheramine salt solution;

[0015] S3. Prepare a bio-based polyamide elastomer;

[0016] Add the polyamide salt solution, the polyetheramine salt solution, and deionized water into a reaction kettle, fill the reaction kettle with a protective gas, raise the temperature and pressure and carry out a pressure-holding reaction, and then obtain the bio-based polyamide elastomer after cooling and depressurizing.

[0017] Furthermore, in step S1, the pH value of the polyamide salt solution is 7.4 - 7.6; in step S2, the pH value of the polyetheramine salt solution is 7.2 - 7.4.

[0018] Further, the amount of deionized water added in step S1 is 20% - 25% of the total mass of the aliphatic straight-chain dibasic acid and the aliphatic straight-chain diamine; the amount of deionized water added in step S2 is 30% - 50% of the total mass of the aliphatic straight-chain dibasic acid and the aliphatic straight-chain diamine; the amount of deionized water added in step S3 is 8 - 13% of the total mass of the diamine monomer and the dibasic acid monomer.

[0019] Further, the reaction temperature in step S1 is 80 - 90 °C; the reaction temperature in step S2 is 80 - 90 °C.

[0020] Further, the temperature increase in step S3 is 230 - 250 °C, the pressure increase is 1.9 - 2.1 MPa, and the pressure holding time is 1 - 2 h.

[0021] Further, the pressure reduction process in step S3 is to reduce the pressure by 0.01 MPa every 10 min until the pressure is reduced to -0.1 MPa.

[0022] Further, the temperature during the pressure reduction process in step S3 is maintained at 230 - 250 °C.

[0023] Further, the bio-based polyamide elastomer is applied to medical products such as medical catheters and balloons, sutures, and medical consumables.

[0024] Compared with the prior art, the beneficial effects are as follows:

[0025] The product obtained by the melt copolymerization of the bio-based straight-chain dibasic acid and the bio-based straight-chain diamine in the present invention is used as the hard segment domain, which not only has the flexibility of the long carbon chain but also has relatively high strength of the polyamide material. At the same time, adding a small amount of the soft segment domain can also endow the material with good flexibility and prevent the strength of the material from being greatly reduced.

[0026] By controlling the types of reactants, the number of reaction monomers, and without any additives, the present invention ensures the biocompatibility of the bio-based polyamide elastomer. On the basis of ensuring good mechanical properties, a simpler preparation process is adopted as much as possible, with fewer raw materials and additives used, to prevent the precipitation of additives from affecting the biocompatibility of the bio-based polyamide elastomer. Description of the Drawings

[0027] Figure 1 is the infrared spectrum of the bio-based polyamide elastomer in Examples 1 - 4;

[0028] Figure 2 is the infrared spectrum of the bio-based polyamide elastomer in Examples 5 - 8;

[0029] Figure 3 is the proton nuclear magnetic resonance spectrum of the bio-based polyamide elastomer in Example 4, Example 8, and Comparative Example 1. Detailed implementation mode

[0030] The following is further explained and clarified in combination with embodiments. However, the specific embodiments do not limit the present invention in any form. Unless otherwise specified, the methods and equipment used in the embodiments are conventional methods and equipment in the art, and the raw materials used are all conventional commercially available raw materials.

[0031] The raw material bio-based pentamethylenediamine used in the present invention is purchased from Yipin New Materials Co., Ltd. in Heilongjiang, China, and the bio-based sebacic acid is purchased from Kaide Bioplastics Co., Ltd. in Hebei, China.

[0032] Example 1

[0033] This example provides a preparation method of a bio-based polyamide elastomer, and the steps include:

[0034] S1. Prepare a polyamide salt solution;

[0035] Mix 956.58 g of bio-based pentamethylenediamine, 1893.42 g of bio-based sebacic acid and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.5. The reaction is expressed as:

[0036]

[0037] S2. Prepare a polyetheramine salt solution;

[0038] Mix 112.8 g of polyetheramine 600, 37.82 g of bio-based sebacic acid and 75 g of deionized water, heat in a water bath to 85 °C and stir to obtain a clear salt solution, and then adjust the pH value to 7.3. The reaction is expressed as:

[0039]

[0040] S3. Prepare a bio-based polyamide elastomer;

[0041] Add the solutions prepared in S1 and S2 to the reaction polymerization kettle, then add 30 g of deionized water, displace the air in the reaction kettle with high-purity nitrogen 5 times, raise the temperature to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, keep the pressure for 1.5 h, then slowly exhaust to atmospheric pressure, and the exhaust time is 1.5 hours. During the exhaust, keep the temperature in the kettle as close as possible to 240 °C, and then start to evacuate. Reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and then discharge the material to obtain the bio-based polyamide elastomer, which is expressed as:

[0042]

[0043] Among them, when y = 9, x + z = 3.6, or when y = 12.5, x + z = 6.

[0044] Example 2

[0045] This example provides a method for preparing a bio-based polyamide elastomer, and the steps include:

[0046] S1. Prepare a polyamide salt solution;

[0047] Mix 906.24 g of bio-based pentamethylenediamine, 1793.76 g of bio-based sebacic acid, and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.5.

[0048] S2. Prepare a polyetheramine salt solution;

[0049] Mix 224.37 g of polyetheramine 600, 75.63 g of bio-based sebacic acid, and 105 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.3.

[0050] S3. Prepare a bio-based polyamide elastomer;

[0051] Add the solutions prepared in S1 and S2 to a reaction polymerization kettle, then add 30 g of deionized water, displace the air in the kettle with high-purity nitrogen 5 times, raise the temperature to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, after maintaining the pressure for 1.5 h, slowly exhaust to atmospheric pressure, and the exhaust time is 1.5 hours. During the exhaust, keep the temperature in the kettle as close as possible to 240 °C, then start to evacuate, reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and discharge the material to obtain the bio-based polyamide elastomer.

[0052] Example 3

[0053] This example provides a method for preparing a bio-based polyamide elastomer, and the steps include:

[0054] S1. Prepare a polyamide salt solution;

[0055] Mix 855.89 g of bio-based pentamethylenediamine, 1694.11 g of bio-based sebacic acid, and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.5.

[0056] S2. Prepare a polyetheramine salt solution;

[0057] Mix 336.55 g of polyetheramine 600, 113.45 g of bio-based sebacic acid, and 150 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.3.

[0058] S3. Prepare a bio-based polyamide elastomer;

[0059] Add the solutions prepared from S1 and S2 into the reaction polymerization kettle, then add 30 g of deionized water, displace the air in the kettle with high-purity nitrogen 5 times, raise the temperature to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, after holding the pressure for 1.5 h, slowly exhaust the gas to atmospheric pressure, the exhaust time is 1.5 hours, keep the temperature in the kettle as close as possible to 240 °C during exhaust, then start to evacuate the air, reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and discharge the material to obtain the bio-based polyamide elastomer.

[0060] Example 4

[0061] This example provides a preparation method of a bio-based polyamide elastomer, and the steps include:

[0062] S1. Prepare a polyamide salt solution;

[0063] Mix 805.54 g of bio-based pentamethylenediamine, 1594.46 g of bio-based sebacic acid and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.5.

[0064] S2. Prepare a polyetheramine salt solution;

[0065] Mix 448.74 g of polyetheramine 600, 151.26 g of bio-based sebacic acid and 180 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.3.

[0066] S3. Prepare the bio-based polyamide elastomer;

[0067] Add the solutions prepared from S1 and S2 into the reaction polymerization kettle, then add 30 g of deionized water, displace the air in the kettle with high-purity nitrogen 5 times, raise the temperature to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, after holding the pressure for 1.5 h, slowly exhaust the gas to atmospheric pressure, the exhaust time is 1.5 hours, keep the temperature in the kettle as close as possible to 240 °C during exhaust, then start to evacuate the air, reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and discharge the material to obtain the bio-based polyamide elastomer.

[0068] Example 5

[0069] This example provides a preparation method of a bio-based polyamide elastomer, and the steps include:

[0070] S1. Prepare a polyamide salt solution;

[0071] Mix 956.58 g of bio-based pentamethylenediamine, 1893.42 g of bio-based sebacic acid and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.5.

[0072] S2. Prepare a polyetheramine salt solution;

[0073] Mix 122.48 g of polyetheramine 900, 27.52 g of bio - based sebacic acid, and 75 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.3.

[0074] S3. Prepare a bio - based polyamide elastomer;

[0075] Add the solutions prepared in S1 and S2 to a reaction polymerization kettle, then add 30 g of deionized water, displace the air in the reaction kettle with high - purity nitrogen 5 times, heat up to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, after maintaining the pressure for 1.5 h, slowly exhaust to atmospheric pressure, the exhaust time is 1.5 hours, during the exhaust, keep the temperature in the kettle as close as possible to 240 °C, then start to evacuate, reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to - 0.1 MPa, and discharge to obtain the bio - based polyamide elastomer.

[0076] Example 6

[0077] This example provides a method for preparing a bio - based polyamide elastomer, and the steps include:

[0078] S1. Prepare a polyamide salt solution;

[0079] Mix 906.24 g of bio - based pentamethylenediamine, 1793.76 g of bio - based sebacic acid, and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.5.

[0080] S2. Prepare a polyetheramine salt solution;

[0081] Mix 244.95 g of polyetheramine 900, 55.05 g of bio - based sebacic acid, and 105 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, then adjust the pH value to 7.3.

[0082] S3. Prepare a bio - based polyamide elastomer;

[0083] Add the solutions prepared in S1 and S2 to a reaction polymerization kettle, then add 30 g of deionized water, displace the air in the reaction kettle with high - purity nitrogen 5 times, heat up to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, after maintaining the pressure for 1.5 h, slowly exhaust to atmospheric pressure, the exhaust time is 1.5 hours, during the exhaust, keep the temperature in the kettle as close as possible to 240 °C, then start to evacuate, reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to - 0.1 MPa, and discharge to obtain the bio - based polyamide elastomer.

[0084] Example 7

[0085] This embodiment provides a method for preparing a bio-based polyamide elastomer, and the steps include:

[0086] S1. Prepare a polyamide salt solution;

[0087] Mix 855.89 g of bio-based pentamethylenediamine, 1694.11 g of bio-based sebacic acid, and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.5.

[0088] S2. Prepare a polyetheramine salt solution;

[0089] Mix 367.43 g of polyetheramine 900, 82.57 g of bio-based sebacic acid, and 150 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.3.

[0090] S3. Prepare a bio-based polyamide elastomer;

[0091] Add the solutions prepared in S1 and S2 to a reaction polymerization kettle, then add 30 g of deionized water, displace the air in the reaction kettle with high-purity nitrogen 5 times, raise the temperature to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, keep the pressure for 1.5 h, then slowly exhaust to atmospheric pressure, with the exhaust time being 1.5 hours. During exhaust, keep the temperature in the kettle as close as possible to 240 °C, and then start to evacuate. Reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and then discharge the material to obtain the bio-based polyamide elastomer.

[0092] Example 8

[0093] This embodiment provides a method for preparing a bio-based polyamide elastomer, and the steps include:

[0094] S1. Prepare a polyamide salt solution;

[0095] Mix 805.54 g of bio-based pentamethylenediamine, 1594.46 g of bio-based sebacic acid, and 600 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.5.

[0096] S2. Prepare a polyetheramine salt solution;

[0097] Mix 489.91 g of polyetheramine 900, 110.09 g of bio-based sebacic acid, and 180 g of deionized water, heat in a water bath to 85 °C and stir until a clear salt solution is obtained, and then adjust the pH value to 7.3.

[0098] S3. Prepare a bio-based polyamide elastomer;

[0099] Add the solutions prepared from S1 and S2 into the reaction polymerization kettle, then add 30 g of deionized water. Replace the air in the kettle with high-purity nitrogen 5 times, heat up to 240 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, keep the pressure for 1.5 h, then slowly exhaust the gas to atmospheric pressure. The exhaust time is 1.5 hours. During the exhaust, keep the temperature in the kettle at 240 °C as much as possible. Then start to evacuate the air. Reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and then discharge the material to obtain the bio-based polyamide elastomer.

[0100] Comparative Example 1

[0101] Compared with Examples 1 - 8, this Comparative Example 1 did not add the polyetheramine soft segment domain. Specifically:

[0102] Add the solution prepared from 1993.07 g of bio-based sebacic acid and 1006.93 g of bio-based pentamethylenediamine into the reaction polymerization kettle, then add 300 g of deionized water. Replace the air in the kettle with high-purity nitrogen 5 times, heat up to 250 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, keep the pressure for 1 h, then slowly exhaust the gas to atmospheric pressure. The exhaust time is 1.5 hours. During the exhaust, keep the temperature in the kettle at 250 °C as much as possible. Then start to evacuate the air. Reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.07 MPa, and then discharge the material to obtain the bio-based polyamide.

[0103] Comparative Example 2

[0104] Compared with Examples 1 - 4, this Comparative Example 2 used a substance composed of caprolactam as the polyamide hard segment domain, and the mass fraction of the hard segment domain in the total mass was 40%. Specifically:

[0105] S1. Prepare the polyetheramine salt solution;

[0106] Mix 1346.21 g of polyetheramine 600, 453.79 g of bio-based sebacic acid and 550 g of deionized water, heat in a water bath and stir until a clear salt solution is obtained, and then adjust the pH value to 7.3 ± 0.1.

[0107] S2. Prepare the bio-based polyamide elastomer;

[0108] Add the solution prepared from S1 into the reaction polymerization kettle, then add 1200 g of caprolactam and 30 g of deionized water. Replace the air in the kettle with high-purity nitrogen 5 times, heat up to 260 °C, maintain the pressure in the kettle at 1.9 - 2.1 MPa, keep the pressure for 1.5 h, then slowly exhaust the gas to atmospheric pressure. The exhaust time is 1.5 hours. During the exhaust, keep the temperature in the kettle at 260 °C as much as possible. Then start to evacuate the air. Reduce the pressure by 0.01 MPa every 10 min starting from 0 until the pressure is reduced to -0.1 MPa, and then discharge the material to obtain the medical-grade bio-based polyamide elastomer.

[0109] Performance Detection

[0110] (1) Infrared spectroscopy tests were carried out on Examples 1-8 and Comparative Example 1. The JYH-127 Frontier Fourier transform infrared spectrometer of PerkinElmer in the United States was used for testing, and the spectral range was 675-4000 cm -1 . Nuclear magnetic resonance hydrogen spectrum tests were carried out on Example 4, Example 8 and Comparative Example 1. As Figures 1 to 3 shown, compared with the comparative example, Figure 1 , Figure 2 the stretching vibration peak at 1105 cm -1 is the characteristic peak of the ether bond C-O-C; Figure 3 the e peak in

[0111] (2) Mechanical property tests were carried out on Examples 1-8 and Comparative Examples 1-2. The tensile properties were tested according to the GB / T 1040.1-2018 standard, the bending properties were tested according to the GB / T 9341-2008 standard, and the impact properties were tested according to the GB / T1843-2008 standard. The test results are shown in Table 1 below:

[0112] Table 1

[0113]

[0114]

[0115] It can be seen from Examples 1-4 that as the content of the soft segment domain increases from 5% to 20%, the tensile properties improve and the flexural strength decreases. It can be seen from Examples 5-8 that as the content of the polyether soft segment increases, the elongation at break of the bio-based polyamide elastomer increases, but the tensile strength, flexural strength and flexural modulus all decrease, that is, the flexibility of the material is enhanced. Compared with the comparative example, the bio-based polyamide elastomers of Examples 1-8 of the present invention have good flexibility while maintaining relatively high strength. In Comparative Example 2, in order to obtain better elongation at break and flexibility, the mass fraction of the soft segment domain accounts for 60%, but the strength is difficult to maintain and there is a relatively large sacrifice.

[0116] (3) In vitro cytotoxicity and hemolysis of Examples 1-4, Example 8 and Comparative Examples 1-2 were tested according to the GB / T 16886.5-2017 standard and the ASTM F756-00 standard to characterize the compatibility of the elastomer. The test results are shown in Table 2 below:

[0117] Table 2

[0118]

[0119]

[0120] As can be seen from Table 2 above, as a soft segment in the elastomer, polyetheramine does not increase the toxicity of the material. The elastomer prepared in the present invention has good biocompatibility, with a high cell survival rate and a low hemolysis rate. The elastomers prepared in the present invention all have good biocompatibility. In Examples 1-4, with the addition of polyetheramine 600, the cell survival rate and hemolysis rate remained stable, showing good cell compatibility and blood compatibility. In Examples 5-8, with the increase in the content of polyetheramine 900, the cell survival rate decreased slightly and the hemolysis rate increased slightly. The content of polyetheramine 900 has a certain impact on biocompatibility. Comparing Examples 1-4 with Examples 5-8, the introduction of polyetheramine 600 enables the material to still maintain good biocompatibility, while the introduction of polyetheramine 900 has an adverse effect on the biocompatibility of the material. When the content of the polyetheramine 900 soft segment reaches 15 wt%, its cell survival rate fails to meet the medical use standard.

[0121] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A bio-based polyamide elastomer, characterized in that: It comprises hard segments and soft segments which are alternately blocked, wherein the mass fraction of the hard segments is 80% to 95%, and the mass fraction of the soft segments is 5% to 20%; the hard segments are polymerized by aliphatic straight-chain dibasic acid and aliphatic straight-chain diamine, and the soft segments are polymerized by aliphatic straight-chain dibasic acid and polyetheramine; the aliphatic straight-chain dibasic acid comprises one or more of bio-based sebacic acid, bio-based adipic acid, and bio-based azelaic acid; the aliphatic straight-chain diamine comprises one or more of bio-based pentamethylenediamine, bio-based hexamethylenediamine, and bio-based decanediamine.

2. The bio-based polyamide elastomer according to claim 1, characterized in that: The number average molecular weight of the polyetheramine is 600-900.

3. A method for preparing a bio-based polyamide elastomer, characterized in that the steps include: S1. preparing a polyamide salt solution; heating aliphatic straight-chain dibasic acid, aliphatic straight-chain diamine and deionized water to react to obtain a polyamide salt solution; S2. preparing a polyetheramine salt solution; The polyetheramine, aliphatic straight-chain dibasic acid and deionized water are heated to react to obtain a polyetheramine salt solution; S3. Preparation of bio-based polyamide elastomer; Add polyamide salt solution, polyetheramine salt solution and deionized water into a reactor, fill the reactor with protective gas, increase the temperature and pressure and carry out pressure-maintaining reaction, and obtain the bio-based polyamide elastomer after reducing the temperature and pressure.

4. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The pH value of the polyamide salt solution in step S1 is 7.4-7.6; the pH value of the polyetheramine salt solution in step S2 is 7.2-7.

4.

5. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The amount of deionized water added in step S1 is 20% to 25% of the total mass of the aliphatic straight-chain dibasic acid and the aliphatic straight-chain diamine; the amount of deionized water added in step S2 is 30% to 50% of the total mass of the aliphatic straight-chain dibasic acid and the aliphatic straight-chain diamine; the amount of deionized water added in step S3 is 8 to 13% of the total mass of the diamine monomer and the dibasic acid monomer.

6. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The reaction temperature in step S1 is 80-90°C; the reaction temperature in step S2 is 80-90°C.

7. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The temperature of the heating in step S3 is 230-250° C., the pressure is 1.9-2.1 MPa, and the pressure holding time is 1-2 hours.

8. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The depressurization process in step S3 is to reduce the pressure by 0.01 MPa every 10 minutes until the pressure reaches -0.1 MPa.

9. The method for preparing the bio-based polyamide elastomer according to claim 3, characterized in that: The temperature of the depressurization process in step S3 is maintained at 230-250°C.

10. The bio-based polyamide elastomer according to claim 1 or 2, characterized in that: The bio-based polyamide elastomer is applied to medical catheters, balloons and sutures.

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