A bio-based polyamide polyester and a method of making and use thereof

Abstract

The application provides a kind of bio-based polyamide polyester and its preparation method and application.The bio-based polyamide polyester is synthesized by using diacid containing amide bond, hydrophobic side chain and biological carbon atom, wherein the hydrophobic side chain reduces the crystallinity of the polyamide polyester and improves its optical transparency; the amide bond gives it excellent temperature resistance, wear resistance and mechanical properties, and the ester bond gives it good impact resistance, higher modulus and strength. The bio-based polyamide polyester provided by the application has the advantages of both engineering plastic polyamide and general plastic polyester, and is a new type of bio-based polymer material, which has potential application value in packaging materials or solar panels and other fields.

Description

Technical Field

[0001] This invention belongs to the field of polymer chemistry technology, specifically relating to a bio-based polyamide polyester, its preparation method, and its application. Background Technology

[0002] Polyamide polyester is a polymer whose molecular chain structure contains amide and ester bonds. Therefore, it possesses both the impact resistance, high modulus, and strength of polyester, and the temperature resistance, abrasion resistance, and mechanical properties of polyamide. Due to the presence of ester bonds, polyamide polyester is easy to process and can be molten into various profiles, making it widely used in the pharmaceutical, biomedical, telecommunications cable, and automotive industries. Simultaneously, the presence of ester bonds endows polyamide polyester with biodegradability, giving it broad application prospects. Although polyesteramide has excellent properties and a wide range of applications, its market development is currently limited, and there is still considerable room for improvement in its technology, production costs, and application areas. For example, the temperature resistance and mechanical properties of existing polyamide polyesters still need improvement, and the development of related polymer materials with high optical transparency is relatively limited, thus restricting the widespread application of polyamide polyester in some fields. Summary of the Invention

[0003] The main objective of this invention is to provide a novel low-crystallinity bio-based polyamide polyester and its preparation method. The diacid monomer used in the polymerization process includes a novel diacid monomer (diacid with hydrophobic side chains shown in Formula II) synthesized from a benzene ring diacid and a compound containing at least one amino group and one carboxyl group with side chain groups. Because it contains amide bonds, the polyamide polyester synthesized using it has high mechanical strength and temperature resistance. Furthermore, the presence of side chain groups improves the transparency of the polymer. In addition, the ester bonds it contains endow the polyamide polyester with good impact resistance, high modulus and strength.

[0004] To achieve the aforementioned objectives, the present invention employs the following technical solutions:

[0005] A first aspect of the present invention is to provide a bio-based polyamide polyester, the bio-based polyamide polyester comprising the structure shown in Formula I:

[0006]

[0007] Wherein, Y is selected from p-benzene or m-benzene, R1, R2, and R3 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups, and n is an integer greater than 50.

[0008] The alkyl group mentioned above can be a straight-chain alkyl group, a branched alkyl group, or a cycloalkyl group.

[0009] In some embodiments, R1 and R2 are independently selected from substituted or unsubstituted C1-C4 alkyl groups, substituted or unsubstituted phenyl groups, or substituted or unsubstituted aromatic heterocyclic groups.

[0010] In some embodiments, R1 and R2 are independently selected from methyl, propyl, isopropyl, isobutyl, sec-butyl, ethyl methyl sulfide, benzyl, or methyl indole groups.

[0011] In some embodiments, R3 is selected from substituted or unsubstituted C2 to C3. 10 Alkyl groups or substituted or unsubstituted phenyl groups.

[0012] In some embodiments, R3 is selected from ethyl, butyl, hexyl, decyl, neopentyl, 1,4-cyclohexanedimethyl or 1,4-di(ethoxy)phenyl.

[0013] In some embodiments, the intrinsic viscosity of the bio-based polyamide polyester is 0.4 dL / g to 2.0 dL / g.

[0014] In some embodiments, the crystallinity of the bio-based polyamide polyester is less than 10%.

[0015] In some embodiments, the bio-based polyamide polyester has a transparency of 85% or higher.

[0016] In some embodiments, the glass transition temperature of the bio-based polyamide polyester is 90–120°C.

[0017] In some embodiments, the number-average molecular weight of the bio-based polyamide polyester is greater than 20,000.

[0018] A second aspect of the present invention is to provide a method for preparing a bio-based polyamide polyester, comprising: performing a polymerization reaction on a mixed reaction system containing a diacid, a diol and a catalyst to obtain a bio-based polyamide polyester; wherein the diacid includes a diacid with a hydrophobic side chain having the structure shown in Formula II;

[0019]

[0020] Wherein, Y is selected from p-benzene or m-benzene, and R1 and R2 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0021] The dicarboxylic acid of Formula II contains hydrophobic side chains and amide bonds. Polyamide polyesters synthesized from it have lower crystallinity, higher transparency, and improved water resistance.

[0022] In some embodiments, the polymerization reaction specifically includes: under an inert atmosphere, the mixed reaction system undergoes a first-stage reaction at a temperature of 100–130°C, followed by a second-stage reaction at 150–180°C, then the vacuum is adjusted to below 500 Pa, and the temperature is raised to 220–270°C for a third-stage reaction. Since the diacid of Formula II exhibits certain instability during polymerization, it is first subjected to esterification at low temperatures to improve its stability. Then, the temperature is increased to raise the molecular weight of the prepolymer, further improving its stability. Finally, polycondensation at high temperatures yields the polyamide polyester. Using a stepwise heating method prevents the diacid from decarboxylating / decomposing, thus avoiding any impact on the degree of polymerization and color of the polymer.

[0023] Furthermore, the reaction time for the first stage is 1 to 3 hours, the reaction time for the second stage is 1 to 3 hours, and the reaction time for the third stage is 1 to 6 hours.

[0024] In some embodiments, R1 and R2 are independently selected from substituted or unsubstituted C1-C4 alkyl groups, substituted or unsubstituted phenyl groups, or substituted or unsubstituted aromatic heterocyclic groups.

[0025] In some embodiments, R1 and R2 are independently selected from methyl, propyl, isopropyl, isobutyl, sec-butyl, ethyl methyl sulfide, benzyl, or methylindole groups. These groups can be derived from bio-based materials and have advantages such as low toxicity and good biocompatibility. At the same time, by adjusting the R1 and R2 groups, the crystallinity of the obtained polymer can be adjusted, thereby adjusting the transparency of the polymer.

[0026] In some embodiments, the diol includes aliphatic diols and / or aromatic diols.

[0027] In some embodiments, the aliphatic diol comprises carbon chain lengths of C2 to C3. 10 Straight-chain, branched, or cyclic aliphatic diols.

[0028] In some embodiments, the aromatic diol includes aromatic diols containing a benzene ring.

[0029] In some embodiments, the diol includes one or more of ethylene glycol, butanediol, propylene glycol, neopentyl glycol, 1,4-cyclohexanediethanol, hydrogenated bisphenol A, hydroquinone bis(hydroxyethyl) ether, resorcinol bis(hydroxyethyl) ether, hexanediol, and decanediol.

[0030] In some embodiments, the dicarboxylic acid further includes aliphatic diacids and / or aromatic diacids.

[0031] In some embodiments, the aliphatic diacid comprises carbon chain lengths of C4 to C6. 10Straight-chain, branched, or cyclic aliphatic diols.

[0032] In some embodiments, the aromatic diacid includes an aromatic diacid containing a benzene ring.

[0033] In some embodiments, the dicarboxylic acid further includes one or more of adipic acid, sebacic acid, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0034] In some embodiments, the catalyst includes one or more of antimony glycolate, antimony trioxide, tetrabutyl titanate, stannous octoate, and germanium dioxide.

[0035] In some embodiments, the catalyst content in the mixed reaction system is below 1000 ppm.

[0036] In some embodiments, the content of the dicarboxylic acid containing hydrophobic side chains shown in Formula II is 5 to 100 wt% of the total amount of the dicarboxylic acid, for example 10 to 100 wt%, 20 to 100 wt%, 30 to 100 wt%, 40 to 100 wt%, 50 to 100 wt%, 60 to 100 wt%, 70 to 100 wt%, 80 to 100 wt%, or 90 to 100 wt%.

[0037] In some preferred embodiments, the content of the diacid with hydrophobic side chains shown in Formula II is 30 to 100 wt% of the total amount of the diacid. When the amount of the diacid shown in Formula II is within the above range, the transparency, temperature resistance and mechanical properties of the polyamide polyester can be significantly improved.

[0038] In some embodiments, the molar ratio of the dicarboxylic acid to the diol is 1:1.1 to 1:1.5, preferably 1:1.1 to 1:1.2.

[0039] A third aspect of the present invention is to provide a bio-based polyamide polyester obtained according to any one of the above-described preparation methods.

[0040] A fourth aspect of the present invention is to provide the application of the aforementioned bio-based polyamide polyester in the preparation of packaging materials or solar panels.

[0041] Compared with the prior art, this application has at least the following beneficial effects:

[0042] 1) The polyamide polyester provided by the present invention is an ordered copolymer of alternating amide bonds and ester bonds, and there is no phase separation phenomenon. Due to the presence of hydrophobic side chain groups, the hydrolysis resistance of the material is improved, the crystallinity of the polymer is reduced, and the transparency of the polymer is improved. At the same time, due to the presence of amide bonds, the temperature resistance of the polymer is improved.

[0043] 2) The present invention uses the diacid shown in Formula II to prepare polyamide polyester, which can be a semi-bio-based source. The synthesized polyamide polyester has certain biocompatibility and degradability. Furthermore, the diacid shown in Formula II contains amide bonds, which can improve the mechanical strength and temperature resistance of the synthesized polyamide polyester. At the same time, the hydrophobic side chains it contains can improve the transparency of the polyamide polyester.

[0044] 3) This invention uses in-situ melt polymerization to synthesize polyamide polyester. The preparation process is simple and easy to operate, which is conducive to mass production and industrialization. The gradual heating method can prevent the decarboxylation / decomposition of diacids from affecting the degree of polymerization and color of the polymer, thus obtaining polyamide polyester with high optical transparency. Attached Figure Description

[0045] Figure 1 This is the DSC curve of the polyamide polyester in Example 3 of the present invention. Detailed Implementation

[0046] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as limiting, but are merely intended to form the basis of the claims and to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0047] Example 1

[0048] Preparation of dicarboxylic acids with structure II:

[0049] Weigh 60g of terephthaloyl chloride and dissolve it in dichloromethane. Weigh 105g of 2-amino-3-methylbutyric acid and dissolve it in an aqueous solution with a pH of 7.5–8.5. Slowly add the terephthaloyl chloride solution dropwise to the 2-amino-3-methylbutyric acid aqueous solution and react for 2 hours. During the reaction, control the pH at 7.5–9 and the reaction temperature at 15±5℃. After the reaction is complete, adjust the pH to between 1 and 2 using hydrochloric acid. Filter and wash with water to obtain a dicarboxylic acid with formula II.

[0050] Weigh 30g of the prepared dicarboxylic acid of formula II, 10.72g of hexanediol, and 0.01g of antimony glycol into a flask. Under nitrogen protection, first heat to 100℃ and react for 3h, then heat to 160℃ and react for 1h. Slowly reduce the vacuum until it drops to 400±20Pa, then slowly heat to 230℃ and react for 5h. After the reaction is completed, cool down to obtain polyamide polyester.

[0051] According to the test method of GB / T 1632-93, the intrinsic viscosity of the prepared polyamide polyester was measured to be 0.62 dL / g; the crystallinity was measured to be 1.8% by differential scanning calorimetry; the transparency was measured to be 94% by the test method of GB / T 2410; and the glass transition temperature was measured to be 113℃ according to the test method of GB / T19466.2-2004.

[0052] Example 2

[0053] In the preparation of the dicarboxylic acid of Formula II, the difference between Example 2 and Example 1 is that 2-amino-3-methylbutyric acid is replaced with 2-amino-4-methylpentanoic acid, and the rest is the same as in Example 1.

[0054] Weigh 30g of a dicarboxylic acid of formula II, 15g of adipic acid, 17.1g of butanediol, and 0.02g of tetrabutyl titanate and place them in a reaction vessel. Under nitrogen protection, first heat to 120℃ and react for 1.5h, then heat to 180℃ and react for 1h, then slowly reduce the vacuum to 500±20Pa, and continue to heat to 250℃ and react for 3h. After the reaction is completed, cool down to obtain polyamide polyester.

[0055] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.89 dL / g, crystallinity to be 3.1%, Tg to be 108°C, and transparency to be 93%.

[0056] Example 3

[0057] In the preparation of the dicarboxylic acid of Formula II, the difference between Example 3 and Example 1 is that 2-amino-3-methylbutyric acid is replaced with 2-amino-3-indolylpropionic acid and terephthalic acid is replaced with isophthalic acid, while the rest is the same as in the Example.

[0058] Weigh 10g of a dicarboxylic acid of formula II, 90g of adipic acid, 89.9g of hexanediol, and 0.05g of germanium dioxide and place them in a reaction vessel. First, heat the vessel to 130℃ and react for 1 hour, then heat it to 180℃ and react for 1 hour. Then, slowly reduce the vacuum to 100±10Pa and continue to heat the vessel to 270℃ and react for 2 hours. After the reaction is completed, cool the vessel to obtain polyamide polyester. Figure 1 This is the DSC curve of the polyamide polyester in Example 3.

[0059] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 1.08 dL / g, the crystallinity to be 9.6%, the Tg to be 93°C, and the transparency to be 87%.

[0060] Example 4

[0061] In the preparation of the dicarboxylic acid of Formula II, the difference between Example 4 and Example 1 is that 2-amino-3-methylbutyric acid is replaced with 2-amino-4-(methyl mercapto)butyric acid and terephthalic acid is replaced with isophthalic acid, while the rest is the same as in Example 1.

[0062] Weigh 40g of the prepared dicarboxylic acid of formula II, 20g of sebacic acid, 39.8g of decanediol, and 0.04g of tetrabutyl titanate and place them in a reaction vessel. First, react at 100℃ for 2h, then raise the temperature to 170℃ and react for 1h. Slowly evacuate to 300±10Pa, and continue to raise the temperature to 220℃ and react for 6h. After the reaction is completed, cool down to obtain polyamide polyester.

[0063] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.52 dL / g, the crystallinity to be 4.2%, the Tg to be 95°C, and the transparency to be 91%.

[0064] Example 5

[0065] In the preparation of the dicarboxylic acid of Formula II, the difference between Example 5 and Example 1 is that 2-amino-3-methylbutyric acid is replaced with 2-amino-3-phenylpropionic acid and terephthalic acid is replaced with isophthalic acid, while the rest is the same as in Example 1.

[0066] Weigh 50g of the prepared dicarboxylic acid of formula II, 30g of succinic acid, 107.1g of hydrogenated bisphenol A, and 0.06g of germanium dioxide and place them in a reaction vessel. Under nitrogen protection, first heat to 110℃ and react for 2h, then heat to 160℃ and react for 1h. Slowly reduce the vacuum to 100±10Pa and continue to heat to 240℃ and react for 3h. After the reaction is completed, cool down to obtain polyamide polyester.

[0067] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.83 dL / g, the crystallinity to be 3.6%, the Tg to be 115°C, and the transparency to be 93%.

[0068] Example 6

[0069] In the preparation of the dicarboxylic acid of Formula II, the difference between Example 5 and Example 1 is that 2-amino-3-methylbutyric acid is replaced with 3-aminopropionic acid and terephthalic acid is replaced with isophthalic acid, while the rest is the same as in Example 1.

[0070] Weigh 80g of the prepared dicarboxylic acid of formula II, 32.4g of neopentyl glycol, and 0.04g of tetrabutyl titanate and place them in a reaction vessel. Under nitrogen protection, the reaction is first carried out at 100℃ for 2h, then heated to 170℃ for 1h, slowly evacuated to 50±5Pa, and then heated to 250℃ for 3h. After the reaction is completed, the temperature is lowered to obtain polyamide polyester.

[0071] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.97 dL / g, the crystallinity to be 1.6%, the Tg to be 116°C, and the transparency to be 96%.

[0072] Example 7

[0073] The only difference between Example 7 and Example 1 is that, in the preparation of polyamide polyester, 10.72g of hexanediol in Example 1 was replaced with 13.05g of 1,4-cyclohexanediethanol, and the rest was carried out in the same manner as in Example 1 to obtain polyamide polyester.

[0074] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be -0.61 dL / g, the crystallinity to be 2.3%, the transparency to be 92%, and the glass transition temperature to be 114°C.

[0075] Example 8

[0076] The only difference between Example 8 and Example 1 is that, in the preparation of polyamide polyester, 10.72g of hexanediol in Example 1 was replaced with 17.95g of hydroquinone dihydroxyethyl ether, and the rest was carried out in the same manner as in Example 1 to obtain polyamide polyester.

[0077] Following the same testing method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.65 dL / g, the crystallinity to be 3.2%, the transparency to be 89%, and the glass transition temperature to be 118°C.

[0078] Example 9

[0079] The only difference between Example 9 and Example 2 is that, in the preparation process of polyamide polyester, 2.25g of dicarboxylic acid of Formula II, 42.75g of adipic acid, 29.76g of butanediol, and 0.02g of tetrabutyl titanate were placed in a reaction vessel for reaction, and the rest was carried out in the same manner as in Example 2 to obtain polyamide polyester.

[0080] Following the same testing method as in Example 1, the intrinsic viscosity of the prepared polyamide polyester was measured to be 0.87 dL / g, the crystallinity to be 21.8%, the Tg of the synthesized polyamide polyester to be 25°C, and the transparency to be 81%.

[0081] Example 10

[0082] The only difference between Example 10 and Example 2 is that, in the preparation process of polyamide polyester, 4.5g of dicarboxylic acid of Formula II, 40.5g of adipic acid, 28.62g of butanediol, and 0.02g of tetrabutyl titanate were placed in a reaction vessel for reaction, and the rest was carried out in the same manner as in Example 2 to obtain polyamide polyester.

[0083] Following the same testing method as in Example 1, the intrinsic viscosity of the prepared polyamide polyester was measured to be 0.82 dL / g, the Tg of the synthesized polyamide polyester was 36°C, the crystallinity was 10.5%, and the transparency was 82%.

[0084] Comparative Example 1

[0085] The only difference between Comparative Example 1 and Example 2 is that, instead of synthesizing the dicarboxylic acid of Formula II beforehand, terephthalic acid and 2-amino-4-methylpentanoic acid were directly used for polymerization, as detailed below:

[0086] 12.7g of terephthalic acid, 20.1g of 2-amino-4-methylpentanoic acid, 15g of adipic acid, 17.1g of butanediol, and 0.02g of tetrabutyl titanate were placed in a reaction vessel. Under nitrogen protection, the temperature was first raised to 120℃ and reacted for 1.5h, then raised to 180℃ and reacted for 1h. The vacuum was then slowly reduced to 500±20Pa, and the temperature was further raised to 250℃ and reacted for 3h. After the reaction was completed, the temperature was lowered to obtain polyamide polyester.

[0087] Following the same test method as in Example 1, the intrinsic viscosity of the polyamide polyester was measured to be 0.55 dL / g, and its Tg was 92°C, crystallinity was 8.6%, and transparency was 56% as measured by DSC.

[0088] Comparing Comparative Example 1 and Example 2, the polyamide polyester synthesized in Example 2 has a glass transition temperature (Tg) of 108°C and a transparency of 93%. This is because the use of a diacid with formula II in Example 2 enables the formed polyamide polyester to be an ordered homopolymer with alternating amide and ester bonds, resulting in a polyamide polyester with a high molecular weight (e.g., a number average molecular weight of over 20,000) and exhibiting a higher glass transition temperature. In contrast, in Comparative Example 1, due to the use of three monomers for polymerization, the chain segment structure is non-uniform during polymerization, exhibiting a block copolymer, and the resulting polymer has a lower glass transition temperature. Furthermore, because 2-amino-4-methylvaleric acid has poor stability, it is prone to self-polymerization or deamination during polymerization, leading to a decrease in polymer molecular weight and a darker color. This invention uses a diacid with formula II, which has better stability and reactivity, to prepare the polyamide polyester, thereby obtaining a polyamide polyester with higher transparency, lower chroma, and higher viscosity.

[0089] Comparative Example 2

[0090] The only difference between Comparative Example 2 and Example 2 is that the dicarboxylic acid of Formula II is replaced with an equimolar amount of terephthalic acid for the polymerization reaction, as follows:

[0091] Take 12.7g of terephthalic acid, 15g of adipic acid, 17.1g of butanediol and 0.02g of tetrabutyl titanate and place them in a reaction vessel. Under nitrogen protection, first heat up to 120℃ and react for 1.5h, then heat up to 180℃ and react for 1h. Then slowly reduce the vacuum to 500±20Pa and continue to heat up to 250℃ and react for 3h. After the reaction is completed, cool down to obtain the polymer.

[0092] The test was conducted using the same method as in Example 1, and its intrinsic viscosity was measured to be 0.49 dL / g. Its Tg was 63°C, crystallinity was 36%, and transparency was 78% as measured by DSC.

[0093] Comparing Comparative Example 2 and Example 2, it can be seen that the polyamide polyester synthesized in Example 2 has a Tg of 108°C and a transparency of 93%. This indicates that the presence of amide bonds can significantly improve the temperature resistance of the polymer, while the presence of side chains improves the transparency of the polyester.

[0094] Comparative Example 3

[0095] 10.2 g of terephthalic acid and 4.5 g of 4-aminobutyric acid were weighed and heated to 130 °C for 2 h. Then, 8.7 g of hexanediol was added, and the temperature was raised to 150 °C for 3 h. The mixture was then evacuated to below 100 Pa and heated to 230 °C for 5 h to obtain a polyamide polyester. Its viscosity was 0.83, crystallinity was 26%, Tg was 105 °C, and transparency was 68%. The polyamide polyester synthesized in this comparative example exhibited higher crystallinity and significantly lower transparency due to the absence of side-chain structures.

[0096] Table 1. Relevant properties of polymers prepared in the embodiments and comparative examples of the present invention.

[0097]

[0098] In summary, this invention utilizes a diacid with a formula II structure containing amide bonds, hydrophobic side chains, and biogenic carbon atoms to prepare polyamide polyester. The hydrophobic side chains reduce the crystallinity of the polyamide-polyester, improving its optical transparency. The amide bonds impart excellent temperature resistance, abrasion resistance, and mechanical properties, while the ester bonds contribute good impact resistance, high modulus, and strength. Therefore, the polymer synthesized in this invention combines the advantages of engineering plastic polyamide and general-purpose plastic polyester, representing a novel bio-based polymer material with potential applications in packaging materials and films.

[0099] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0100] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0101] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A bio-based polyamide polyester, characterized in that: The bio-based polyamide polyester is an ordered copolymer with alternating amide and ester bonds, and includes the structure shown in Formula I: ； Formula I; In Formula I, Y is selected from p-benzene or m-benzene; R1 and R2 are independently selected from substituted or unsubstituted C1-C4 alkyl groups, substituted or unsubstituted phenyl groups, or substituted or unsubstituted aromatic heterocyclic groups; R3 is selected from substituted or unsubstituted C2-C4 groups. 10 Alkyl or substituted or unsubstituted phenyl, where n is an integer greater than 50; The preparation method of the bio-based polyamide polyester includes: under an inert atmosphere, a mixed reaction system containing a diacid, a diol, and a catalyst is subjected to a polymerization reaction, specifically including: the mixed reaction system is first subjected to a first-stage reaction at a temperature of 100-130°C, then the temperature is raised to 150-180°C for a second-stage reaction, then the vacuum degree is adjusted to below 500 Pa, and the temperature is raised to 220-270°C for a third-stage reaction; the diacid includes a diacid with hydrophobic side chains having the structure shown in Formula II; and the content of the diacid with hydrophobic side chains shown in Formula II is 30-100 wt% of the total amount of the diacid; ； Formula II; In Formula II, Y is selected from p-benzene or m-benzene, and R1 and R2 are independently selected from substituted or unsubstituted C1~C4 alkyl groups, substituted or unsubstituted phenyl groups, or substituted or unsubstituted aromatic heterocyclic groups. The bio-based polyamide polyester has a crystallinity of less than 10%, a transparency of more than 85%, and a glass transition temperature of 90~120℃.

2. The bio-based polyamide polyester according to claim 1, characterized in that, The bio-based polyamide polyester satisfies at least one of the following conditions: a. R1 and R2 are independently selected from methyl, propyl, isobutyl, sec-butyl, ethyl methyl sulfide, benzyl or methylindole groups; b. R3 is selected from ethyl, butyl, hexyl, decyl, neopentyl, 1,4-cyclohexanedimethyl or 1,4-bis(ethoxy)phenyl; c. The intrinsic viscosity of the bio-based polyamide polyester is 0.4 dL / g to 2.0 dL / g; d. The number average molecular weight of the bio-based polyamide polyester is greater than 20,000.

3. The bio-based polyamide polyester according to claim 1, characterized in that: The reaction time for the first stage is 1-3 hours, the reaction time for the second stage is 1-3 hours, and the reaction time for the third stage is 1-6 hours.

4. The bio-based polyamide polyester according to claim 1, characterized in that: The diols include aliphatic diols and / or aromatic diols.

5. The bio-based polyamide polyester according to claim 4, characterized in that: The diols include one or more of ethylene glycol, butanediol, propylene glycol, neopentyl glycol, 1,4-cyclohexanediol, hydrogenated bisphenol A, hydroquinone bis(hydroxyethyl) ether, resorcinol bis(hydroxyethyl) ether, hexanediol, and decanediol.

6. The bio-based polyamide polyester according to claim 1, characterized in that: The dicarboxylic acid also includes aliphatic diacids and / or aromatic diacids.

7. The bio-based polyamide polyester according to claim 1, characterized in that: The dicarboxylic acid also includes one or more of adipic acid, sebacic acid, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

8. The bio-based polyamide polyester according to claim 1, characterized in that: The catalyst includes one or more of the following: antimony glycolate, antimony trioxide, tetrabutyl titanate, stannous octoate, and germanium dioxide.

9. The bio-based polyamide polyester according to claim 1, characterized in that: The molar ratio of the dicarboxylic acid to the diol is 1:1.1 to 1:1.

5.

10. The use of the bio-based polyamide polyester according to any one of claims 1-9 in the preparation of packaging materials or solar panels.

Images