Bio-based polyesteramide elastomer, foam and preparation method thereof

Abstract

The invention discloses a bio-based polyesteramide elastomer, foam and a preparation method thereof, and the preparation method comprises the following steps: under the protection of inert gas, mixing the raw materials, a catalyst and other auxiliaries according to a ratio, carrying out esterification reaction to generate an oligomer, and then carrying out condensation polymerization under a vacuum condition to obtain the bio-based polyesteramide elastomer, the raw materials comprise aliphatic dihydric alcohol, 2, 5-furan dibasic acid, isophthalic acid, aliphatic diamine and polyester dihydric alcohol. According to the invention, through monomer selection and proportion adjustment, the requirements of different strengths, elasticity and light transmittance can be met; the material can be applied to preparation of high-strength and high-toughness bio-based polyesteramide foam, and obviously has positive practical significance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a bio-based polyesteramide elastomer, foam and a preparation method thereof. Background Art

[0002] Nylon (PA) is a nitrogen-containing heterochain polymer containing polyamide characteristic groups (-NHCO-) in the main chain, and is known as one of the five general engineering plastics together with polycarbonate, polyoxymethylene, polybutylene terephthalate and polyphenylene ether. PA has excellent properties such as wear resistance, impact resistance, fatigue resistance, and corrosion resistance. With the continuous emergence of high-value-added modified products, it is widely used in fields such as electronic appliances, the automotive industry, and textile equipment. However, PA also has disadvantages such as poor transparency, which limits its application range. And general transparent materials cannot meet the occasions with higher requirements for physical and mechanical properties. Moreover, most of the raw materials used for synthesizing polyamide still come from the increasingly scarce non-renewable petrochemical resources, and there are certain limitations in long-term use. Based on the defects of traditional PA, it is of great significance to study environmentally friendly bio-based transparent PA with excellent comprehensive properties.

[0003] 2,5-Furandicarboxylic acid (FDCA) is the only aromatic compound among the 12 bio-based platform compounds produced from sugars screened by the US Department of Energy. FDCA can undergo reactions such as oxidation, reduction, and amidation to obtain various furan derivatives with application potential. Therefore, more and more researchers use FDCA and its derivatives to synthesize furan-based polyamides. However, in the prior art, most researchers' research on furan-based polyamides mainly focuses on their synthesis. The decarboxylation during the high-temperature process, the fracture of the furan ring, and the inactivation of the active end groups of oligomers will result in low molecular weight, yellowing of the bio-based furan polyamide, and even the product itself may be toxic. Therefore, most 2,5-furanyl polyamides are synthesized after being methyl esterified and then used as raw materials. However, the small molecules to be removed from the methyl esterified product change from water to methanol, which requires high equipment requirements and is highly harmful.

[0004] Polymer foaming materials are widely used in fields such as aerospace, medical devices, automotive parts, packaging and sports equipment, and microelectronics because of their characteristics such as light weight, heat insulation, insulation, sound insulation, and buffering and shock absorption, far exceeding traditional solid polymer materials. They are currently one of the most popular lightweight and high-performance materials. At present, the preparation of foaming materials is mainly divided into chemical foaming method and physical foaming method. Among them, there are many problems in the chemical foaming process, such as difficult reaction control, resulting in unstable local temperature, and the generation of gaseous products harmful to the environment. The physical foaming method is a method of preparing foaming materials by changing the solubility of physical foaming agents in the polymer system through physical principles. Among them, supercritical CO 2It has liquid-like solubility and gas-like diffusion coefficient. Compared with physical foaming agents harmful to the atmosphere such as chemical foaming agents and Freon, it has the characteristics of non-toxicity, non-flammability, environmental friendliness, easy availability, low price, etc., and is gradually being accepted in production.

[0005] Patent CN115746295A discloses a high-strength, high-toughness and high-barrier polyester amide; by adding a small amount of diamine segments for copolymerization, a polyester amide with high mechanical strength, high modulus and high barrier is prepared; however, the elongation at break of the material is less than 100%, and it does not belong to the elastomer material; at the same time, the application of the material in light transmission and foaming is not described.

[0006] Patent CN116425983A discloses a high-impact polyether ester amide material; a series of polyether amide materials are synthesized by copolymerizing an aliphatic cyclic polyester, an aliphatic polyether and an aliphatic diamine, and it has a good elongation at break; however, the preparation of the aliphatic cyclic polyester monomer is relatively difficult, and since all the synthesized monomers are aliphatic, the tensile strength of the material is only about 20 MPa, which cannot meet the high-strength requirement, and the application of the material in the fields of light transmittance and foaming is not mentioned.

[0007] Patent CN118834384A discloses a preparation method of a bio-based furan copolymer amide; its goal is to avoid side reactions and prepare a high-molecular-weight furan-based polyamide. By first synthesizing an amino-terminated furan diamine prepolymer and then polymerizing it with a dicarboxylic acid, a furan copolymer amide is generated; however, the reaction needs to be prepared by a two-step method, and at the same time, during the polymerization process, it is necessary to sample and measure to determine the molecular weight before the next feeding reaction, and the glass transition temperature of the product is much higher than room temperature, and it does not belong to the elastomer material.

[0008] Patent CN116813969A discloses a foaming method of polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolymer; by isothermal crystallization and quenching treatment, the melt strength of the material is improved, and a polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolymer foaming material is prepared; however, in order to maintain a high degree of crystallization, isothermal crystallization treatment is required, and only solid-state foaming technology can be used. The foaming window is small, and it belongs to a plastic foaming material with a low rebound rate.

[0009] In view of this, the present invention relates to a high-strength, high-toughness, light-transmitting bio-based polyester amide elastomer, foam and its preparation method, which improves the transparency, strength and elongation at break of 2,5-furanyl polyamide. By selecting monomers and adjusting the ratio, different strength, elasticity and light transmittance requirements can be achieved; the material can be applied to the preparation of high-strength and high-toughness bio-based polyester amide foam, which obviously has positive practical significance. Summary of the Invention

[0010] The object of the present invention is a bio-based polyesteramide elastomer, foam and its preparation method. The preparation process is simple, the molecular structure is controllable, the strength and elasticity are controllable, the light transmission effect is obvious, and supercritical foaming can be carried out to prepare a foamed material with uniform cell size and controllable foaming ratio.

[0011] To achieve the above object of the invention, the technical solution adopted by the present invention is: a preparation method of a bio-based polyesteramide elastomer, comprising: under the protection of an inert gas, mixing raw materials, a catalyst and other additives in proportion, carrying out an esterification reaction to generate an oligomer, and then carrying out a polycondensation reaction under vacuum conditions to obtain the bio-based polyesteramide elastomer; The raw materials include aliphatic diols, 2,5-furandicarboxylic acid, isophthalic acid, aliphatic diamines, and polyester diols; The molar ratio of the aliphatic diamine to the total molar amount of 2,5-furandicarboxylic acid and isophthalic acid is (0.6~1.2):1; The 2,5-furandicarboxylic acid accounts for 20~80 mol% of the sum of the molar amounts of 2,5-furandicarboxylic acid and isophthalic acid; The dosage of the polyester diol accounts for 10~90 mol% of the total molar amount of 2,5-furandicarboxylic acid and isophthalic acid; The dosage of the catalyst is 0.02~0.5% of the total mass of the reaction monomers; The dosage of other additives is 0.1~10% of the total mass of the reaction monomers.

[0012] Preferably, the aliphatic diamine is one or more of ethylenediamine, 1,3-propanediamine, 1,2-butanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,5-pentanediamine.

[0013] Preferably, the polyester diol is one or more of polycarbonate diol, polyadipate diol, and polycaprolactone diol.

[0014] Preferably, the number average molecular weight of the polyester diol is 500~3000.

[0015] Preferably, the catalyst is one or more of zinc acetate, titanium dioxide, antimony trioxide, antimony acetate, aluminum acetylacetonate, dibutyltin oxide, stannous oxalate, tetrabutyl titanate, and isopropyl titanate.

[0016] Preferably, the other additives are one or more of antioxidants, UV absorbers, mold release agents, pigments, lubricants, and matting agents.

[0017] Preferably, the inert gas is nitrogen or argon; the temperature of the esterification reaction is 150~280 °C, and the time of the esterification reaction is 1~6 h; Preferably, the temperature of the esterification reaction is 150-280 °C, and the time of the esterification reaction is 2-5 h.

[0018] Preferably, the temperature of the polycondensation reaction is 180-280 °C; the time of the polycondensation reaction is 1-3 h.

[0019] The principle of this application is as follows: The reaction activity of carboxyl and amino is much greater than that of carboxyl and hydroxyl. Therefore, by directly reacting 2,5-furandicarboxylic acid with aliphatic diamine, the preparation of 2,5-furan polyamide material can be achieved at a lower temperature with a faster reaction rate. Polyester diol has higher chain segment polarity, stronger rigidity and better heat resistance than polyether diol. By adding polyester diol soft segment to 2,5-furanyl polyamide, the crystallization can be well destroyed by virtue of the good compatibility between polyester and polyamide. In addition, by utilizing the strong hydrogen bond formed between amide-amide and amide-ester, while maintaining the high strength and foamability of the material, a high-strength and light-transmitting polyester amide elastomer material is prepared. The method proposed by the present invention is an effective way to improve the transparency, strength and elongation at break of 2,5-furanyl polymer materials, broaden the application and realize the high-value utilization.

[0020] This application also claims to protect a bio-based polyester amide elastomer prepared by the preparation method described above. The intrinsic viscosity of the bio-based polyester amide elastomer is 0.5-2.0 dL / g; the glass transition temperature is -40-15 °C; the tensile strength is 100-300 MPa; the elongation at break is greater than 300%.

[0021] This application also claims to protect a preparation method of a bio-based polyester amide foam. The bio-based polyester amide elastomer prepared by the preparation method described above is successively subjected to saturated adsorption and pressure-relief foaming in an environment containing a gas foaming agent to obtain the bio-based polyester amide foam; The temperature of the saturated adsorption is (Tm-30) °C to (Tm+5) °C, where Tm is the melting temperature of the bio-based polyester amide elastomer.

[0022] Preferably, the pressure of the saturated adsorption is 4-20 MPa, and the time is 30-120 min; the pressure-relief speed of the pressure-relief foaming is 0.1-300 MPa / s.

[0023] This application also claims to protect a bio-based polyester amide foam prepared by the preparation method of the bio-based polyester amide foam described above.

[0024] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: 1. The present invention utilizes the characteristic that the amino group has a relatively fast reaction activity to reduce the possibility of decarboxylation of 2,5-furandicarboxylic acid during a long polymerization reaction through a rapid reaction; prepares an elastomeric material by utilizing the characteristic that the polyester diol has a low glass transition temperature; achieves high transparency by utilizing the characteristic that the polyester diol has good compatibility with other monomers; and simultaneously increases the melt strength of the material and improves its foaming performance by utilizing the rich hydrogen bond content.

[0025] 2. By selecting monomers and adjusting their proportions, the present invention can meet different requirements for strength, elasticity, and light transmittance; meanwhile, after supercritical foaming of the material, a high-strength, high-toughness, and high-rebound bio-based polyester amide foam with uniform cell size and controllable foaming ratio can be obtained. This material can fully meet the applications in automobiles, electronic appliances, industrial preparation, and sports goods. Detailed implementation manners

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Unless otherwise specified, those not indicating specific conditions in the embodiments of the present invention are carried out according to conventional conditions or conditions recommended by the manufacturer. The raw materials, reagents, etc. not indicating the manufacturer can be obtained as conventional products through commercial purchase. The materials involved in the following embodiments can all be obtained from commercial channels.

[0028] Example 1 In this example, 0.63 mol of 2,5-furandicarboxylic acid, 0.27 mol of isophthalic acid, 0.972 mol of 1,4-butanediamine, 0.09 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and antioxidant 1098 accounting for 0.1% of the total mass of the reaction monomers were added to the reaction kettle. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min for an esterification reaction for 3 h; then the polymerization temperature was raised to 260 °C and polycondensation was carried out for 2 h under a high vacuum of less than 100 Pa. Immediately after the polycondensation was completed, the product was discharged. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0029] The dried product was placed in a circular mold with a diameter of 20 mm and pressed into a circular sheet with a thickness of 2 mm on a molding press at 180 °C. The circular sheet was placed in a vacuum oven at 30 °C for 8 h; then the circular sheet was placed in a high-pressure foaming device, and the air therein was replaced by purging with CO 2 By a pressurizing device, CO was added to the reaction kettle 2At a pressure of 0 to 15 MPa, the wafer is saturatedly adsorbed in a CO atmosphere at a temperature of 145 °C for 1 h. 2 The pressure is rapidly released at a rate of 200 MPa / s, and the obtained foam is quickly placed in ice water for cooling until the cell structure is fixed.

[0030] Example 2 In this example, 0.45 mol of 2,5-furandicarboxylic acid, 0.45 mol of isophthalic acid, 0.972 mol of 1,4-butanediamine, 0.09 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and 0.1% of antioxidant 1098 based on the total mass of the reaction monomers are added to the reaction kettle. Under nitrogen protection, the temperature is raised to 210 °C and the rotation speed is set to 200 r / min for esterification reaction for 3 h; then the polymerization temperature is raised to 260 °C and polycondensation is carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation ends. The product is dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0031] The dried product is placed in a circular mold with a diameter of 20 mm and pressed into a wafer with a thickness of 2 mm on a molding press at 180 °C. The wafer is placed in a vacuum oven at 30 °C for 8 h; then the wafer is placed in a high-pressure foaming device, and the air in it is replaced by CO purge in this high-pressure foaming device. 2 CO is added to the reaction kettle through a pressurizing device 2 At a pressure of 0 to 15 MPa, the wafer is saturatedly adsorbed in a CO atmosphere at a temperature of 145 °C for 1 h. 2 The pressure is rapidly released at a rate of 200 MPa / s, and the obtained foam is quickly placed in ice water for cooling until the cell structure is fixed.

[0032] Example 3 In this example, 0.27 mol of 2,5-furandicarboxylic acid, 0.63 mol of isophthalic acid, 0.972 mol of 1,4-butanediamine, 0.09 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and 0.1% of antioxidant 1098 based on the total mass of the reaction monomers are added to the reaction kettle. Under nitrogen protection, the temperature is raised to 210 °C and the rotation speed is set to 200 r / min for esterification reaction for 3 h; then the polymerization temperature is raised to 260 °C and polycondensation is carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation ends. The product is dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0033] The dried product is placed in a circular mold with a diameter of 20 mm and pressed into a wafer with a thickness of 2 mm on a molding press at 180 °C. The wafer is placed in a vacuum oven at 30 °C for 8 h; then the wafer is placed in a high-pressure foaming device, and the air in it is replaced by CO purge in this high-pressure foaming device. 2Purge to displace the air therein. Add CO to the reaction kettle through a pressurizing device 2 to a pressure of 15 MPa, and the wafer is saturatedly adsorbed in the CO atmosphere at a temperature of 145 °C for 1 h. Rapidly relieve the pressure at a rate of 200 MPa / s, and quickly place the obtained foam in ice water for cooling until the cell structure is fixed. 2

[0034] Example 4 In this example, 0.63 mol of 2,5-furandicarboxylic acid, 0.27 mol of isophthalic acid, 0.864 mol of 1,4-butanediamine, 0.18 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and antioxidant 1098 accounting for 0.1% of the total mass of the reaction monomers were added to the reaction kettle. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min for esterification reaction for 3 h; then the polymerization temperature was raised to 260 °C and polycondensation was carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation is completed. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0035] Place the dried product in a circular mold with a diameter of 20 mm, press it into a wafer with a thickness of 2 mm on a molding press at 180 °C, and place the wafer in a vacuum oven at 30 °C for 8 h; then place the wafer in a high-pressure foaming device, and in this high-pressure foaming device, purge with CO 2 to displace the air therein. Add CO to the reaction kettle through a pressurizing device 2 to a pressure of 15 MPa, and the wafer is saturatedly adsorbed in the CO atmosphere at a temperature of 145 °C for 1 h. Rapidly relieve the pressure at a rate of 200 MPa / s, and quickly place the obtained foam in ice water for cooling until the cell structure is fixed. 2

[0036] Example 5 In this example, 0.63 mol of 2,5-furandicarboxylic acid, 0.27 mol of isophthalic acid, 0.648 mol of 1,4-butanediamine, 0.36 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and antioxidant 1098 accounting for 0.1% of the total mass of the reaction monomers were added to the reaction kettle. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min for esterification reaction for 3 h; then the polymerization temperature was raised to 260 °C and polycondensation was carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation is completed. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0037] ​​Place the dried product in a circular mold with a diameter of 20 mm, and press it into a wafer with a thickness of 2 mm on a molding press at 180 °C. Place the wafer in a vacuum oven at 30 °C for 8 h. Then place the wafer in a high-pressure foaming device, and displace the air therein by purging with CO 2 Blow. Add CO 2 to the autoclave through a pressurizing device until a pressure of 15 MPa is reached. The wafer is saturated and adsorbed in a CO 2 atmosphere at a temperature of 145 °C for 1 h. Rapidly release the pressure at a rate of 200 MPa / s, and quickly place the obtained foam in ice water to cool until the cell structure is fixed.

[0038] Comparative Example 1 In this example, 0.63 mol of 2,5-furandicarboxylic acid, 0.27 mol of isophthalic acid, 0.972 mol of 1,4-butanediamine, 0.09 mol of polytetrahydrofuran-2000, 0.00084 mol of tetrabutyl titanate, and 0.1% of antioxidant 1098 based on the total mass of the reaction monomers were added to the autoclave. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min, and the esterification reaction was carried out for 3 h. Then the polymerization temperature was raised to 260 °C and polycondensation was carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation is completed. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0039] Place the dried product in a circular mold with a diameter of 20 mm, and press it into a wafer with a thickness of 2 mm on a molding press at 180 °C. Place the wafer in a vacuum oven at 30 °C for 8 h. Then place the wafer in a high-pressure foaming device, and displace the air therein by purging with CO 2 Blow. Add CO 2 to the autoclave through a pressurizing device until a pressure of 15 MPa is reached. The wafer is saturated and adsorbed in a CO 2 atmosphere at a temperature of 145 °C for 1 h. Rapidly release the pressure at a rate of 200 MPa / s, and quickly place the obtained foam in ice water to cool until the cell structure is fixed.

[0040] Comparative Example 2 In this example, 0.63 mol of 2,5-furandicarboxylic acid, 0.27 mol of isophthalic acid, 0.972 mol of 1,4-butanediol, 0.09 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and antioxidant 1098 accounting for 0.1% of the total mass of the reaction monomers were added to the reaction kettle. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min for an esterification reaction for 3 h; then the polymerization temperature was raised to 260 °C and polycondensation was carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation is completed. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0041] The dried product was placed in a circular mold with a diameter of 20 mm and pressed into a round sheet with a thickness of 2 mm on a molding press at 180 °C. The round sheet was placed in a vacuum oven at 30 °C for 8 h; then the round sheet was placed in a high-pressure foaming device, and the air therein was displaced by blowing with CO 2 Purge. CO was added to the reaction kettle through a pressurizing device 2 To a pressure of 15 MPa, and the round sheet was saturatedly adsorbed in a CO atmosphere at a temperature of 145 °C for 1 h. The pressure was rapidly released at a rate of 200 MPa / s, and the obtained foam was quickly placed in ice water and cooled until the cell structure was fixed. 2

[0042] Comparative Example 3 In this example, 0.09 mol of 2,5-furandicarboxylic acid, 0.972 mol of 1,4-butanediamine, 0.09 mol of polycaprolactone-2000, 0.00084 mol of tetrabutyl titanate, and antioxidant 1098 accounting for 0.1% of the total mass of the reaction monomers were added to the reaction kettle. Under nitrogen protection, the temperature was raised to 210 °C and the rotation speed was set to 200 r / min for an esterification reaction for 3 h; then the polymerization temperature was raised to 260 °C and polycondensation was carried out under a high vacuum of less than 100 Pa for 2 h. Immediately discharge the material after the polycondensation is completed. The product was dried in a vacuum at 30 °C for 12 h to obtain the final product.

[0043] The dried product was placed in a circular mold with a diameter of 20 mm and pressed into a round sheet with a thickness of 2 mm on a molding press at 180 °C. The round sheet was placed in a vacuum oven at 30 °C for 8 h; then the round sheet was placed in a high-pressure foaming device, and the air therein was displaced by blowing with CO 2 Purge. CO was added to the reaction kettle through a pressurizing device 2 To a pressure of 15 MPa, and the round sheet was saturatedly adsorbed in a CO atmosphere at a temperature of 145 °C for 1 h. The pressure was rapidly released at a rate of 200 MPa / s, and the obtained foam was quickly placed in ice water and cooled until the cell structure was fixed. 2

[0044] The elastomers and their foams prepared in the above Examples 1 to 5 and Comparative Examples 1 to 3 were tested, and the test results are shown in Table 1 below.

[0045] Table 1

[0046] As can be seen from Table 1 above, in Examples 1 to 5, by changing the proportions of isophthalic acid and polyester diol, the ratio of hard and soft segments of the elastomer can be adjusted, and a high-strength, high-toughness, and light-transmitting bio-based polyester elastomer can be prepared. Moreover, through foaming exploration, the foaming ratio is greater than 10 times, and the foam cells are dense and uniform, meeting the requirements of different strengths, elasticities, and foaming ratios.

[0047] In Comparative Example 1, polytetrahydrofuran was used as the reaction raw material, and the strength could not meet the high-strength requirements.

[0048] In Comparative Example 2, 1,4-butanediol was used as the reaction raw material. The esterification reaction was slow, and the decarboxylation of 2,5-furandicarboxylic acid was severe, resulting in low molecular weight and melt strength of the material, as well as low tensile strength and foaming ratio.

[0049] In Comparative Example 3, isophthalic acid was not used, and the light-transmitting performance of the material was poor.

[0050] In the above text, the product test and characterization methods used in the examples and comparative examples of the present invention are as follows: Test method for cell size density: Observe the cell morphology of the cross-section of the foam sample through a field emission electron microscope (SEM, Nove NanoSEM450, FEI). Use Image Pro Plus software to analyze the SEM images and calculate the average cell diameter and cell density of the sample after foaming.

[0051] Test method for foam density: Use a density meter to test the density of the sample and the foamed sample. The foaming ratio of the sample is defined as the ratio of the density of the sample before foaming to the density of the sample after foaming.

[0052] Test method for light transmittance: Place the dried sample in a mold and prepare a sample plate with a size of 4 cm * 4 cm and a thickness of 3 mm through hot pressing. Test it with a WGT-S light transmittance tester. For each test, select 5 positions on the film for experiments and repeat three times, and take the average value.

[0053] Test method for mechanical properties: Use a universal testing machine to test the tensile properties of the material. The copolymer is hot-pressed into a 1-mm-thick film and cut into dumbbell-shaped specimens. The samples are placed at room temperature for a period of time and then subjected to tensile testing at a speed of 50 mm / min, and at least five tests are performed on each sample with different contents.

[0054] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a bio-based polyester amide elastomer, characterized in that: include: Under the protection of an inert gas, the raw materials, the catalyst, and other additives are mixed in proportion, and an esterification reaction is performed to generate an oligomer, and then a polycondensation reaction is performed under vacuum conditions to obtain the bio-based polyester amide elastomer; The raw materials include aliphatic diols, 2,5-furan dicarboxylic acid, isophthalic acid, aliphatic diamines, and polyester diols; The total molar ratio of the aliphatic diamine to 2,5-furan dicarboxylic acid and isophthalic acid is (0.6-1.2):1; The 2,5-furan dicarboxylic acid accounts for 20-80 mol% of the total molar number of 2,5-furan dicarboxylic acid and isophthalic acid; The amount of the polyester diol is 10-90 mol% of the total moles of 2,5-furan dicarboxylic acid and isophthalic acid; The amount of catalyst used is 0.02~0.5% of the total monomer mass of the reaction; The dosage of other additives is 0.1~10% of the total monomer mass of the reaction.

2. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The aliphatic diamine is one or more of ethylenediamine, 1,3-propylenediamine, 1,2-butylenediamine, 1,3-butylenediamine, 1,4-butylenediamine, and 1,5-pentanediamine.

3. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The polyester diol is one or more of polycarbonate diol, polyadipate diol and polycaprolactone diol.

4. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The number average molecular weight of the polyester diol is 500-3000.

5. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The catalyst is one or more of zinc acetate, titanium dioxide, antimony trioxide, antimony acetate, aluminum acetylacetonate, dibutyltin oxide, stannous oxalate, tetrabutyl titanate and isopropyl titanate.

6. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The other auxiliary agents are one or more of antioxidants, anti-ultraviolet agents, release agents, pigments, lubricants and matting agents.

7. The method for preparing a bio-based polyester amide elastomer according to claim 1, characterized in that: The inert gas is nitrogen or argon; the temperature of the esterification reaction is 150-280°C, and the time of the esterification reaction is 1-6 hours; The temperature of the polycondensation reaction is 180-280° C.; the vacuum degree of the polycondensation reaction is below 300 Pa; and the time of the polycondensation reaction is 1-5 hours.

8. A bio-based polyester amide elastomer, characterized in that: The bio-based polyester amide elastomer is prepared by the preparation method according to any one of claims 1 to 7, wherein the intrinsic viscosity of the bio-based polyester amide elastomer is 0.5-2.0 dL / g; the glass transition temperature is -40~15°C; the tensile strength is 100~300MPa; and the elongation at break is greater than 300%.

9. A method for preparing bio-based polyester amide foam, characterized in that: The bio-based polyester amide elastomer prepared by the preparation method according to any one of claims 1 to 7 is subjected to saturated adsorption and pressure release foaming in an environment containing a gas foaming agent to obtain the bio-based polyester amide foam; The saturated adsorption temperature is (Tm-30)°C to (Tm+5)°C, where Tm is the melting temperature of the bio-based polyester amide elastomer.

10. The method for preparing a bio-based polyester amide foam according to claim 9, characterized in that: The saturated adsorption pressure is 4-20 MPa, and the time is 30-120 min; the pressure relief speed of the pressure relief foaming is 0.1-300 MPa / s.

11. A bio-based polyester amide foam, characterized in that: The bio-based polyester amide foam is prepared by the preparation method of any one of claims 9 to 10.

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