Bio-based PEST material with side chain containing heterocyclic structure

Abstract

The invention provides a bio-based PEST material with a side chain containing a heterocyclic structure. The bio-based PEST material with the side chain containing the heterocyclic structure comprises a chain segment unit obtained after side chain heterocyclic structure diol and / or side chain heterocyclic structure diacid are polymerized. Through copolymerization modification, the mechanical properties and thermal properties of the PEST material are improved, and the PEST material can be better applied to high-barrier products.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a PEST material with a heterocyclic side chain structure. Background Technology

[0002] PET is the world's most produced polyester material. PET products have high mechanical strength and excellent transparency, and can be widely used in bottle materials, spun polyester, food packaging, and other fields. In today's advocacy for plastic pollution control, PET's non-degradability has become the leading cause of marine pollution. Although PET is easy to recycle, the recycling rate is less than 30%, and recycling causes secondary pollution, further increasing environmental harm. Therefore, improving the degradability of PET has become a hot research topic in recent years.

[0003] PEST material is a polyester copolymerized from terephthalic acid, ethylene glycol, and succinic acid. It combines the rigidity and strength of PET polyester with the degradation characteristics of PES polyester, making it an excellent biodegradable material. Its degradation characteristics are related to the proportion of terephthalic acid (T) content; the higher the T content, the slower the degradation rate. Furthermore, the succinic acid in PEST can be obtained through bio-fermentation, thus PEST is a bio-based biodegradable polyester material.

[0004] Eastman Semiconductor produces PETG (20%-70% CHDM) and PCT (100% CHDM) materials by adding appropriate amounts of CHDM monomer to PET materials. These products offer high transparency, good barrier properties, and excellent thermal performance. 1,4-Cyclohexanediethanol monomers have high rigidity, large steric hindrance, and good heat resistance. Adding them to the polyester backbone disrupts the original regular crystal structure of PET, resulting in a significantly lower glass transition temperature compared to PET, while maintaining twice the barrier properties and significantly improved temperature resistance.

[0005] Polyester PEF formed from furanyl dicarboxylic acid (FDCA) and ethylene glycol, and polyester PETF formed from FDCA, ethylene glycol, and terephthalic acid, offer improved performance compared to traditional PEF materials. PETF materials exhibit some biodegradability, although the degradation rate is relatively slow. PETF materials with a conjugated furan ring structure demonstrate a 1-fold increase in barrier properties and a roughly 10°C increase in heat distortion temperature compared to PET, reaching 85°C. Summary of the Invention

[0006] In view of this, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a PEST material with a heterocyclic side chain, wherein the PEST material is a polymer comprising copolymer units of terephthalic acid, succinic acid, and ethylene glycol, comprising repeating unit segments of formulas XI to XIII as follows:

[0008]

[0009] The characteristic feature is that the PEST material with a heterocyclic side chain comprises segment units obtained by polymerization of heterocyclic diols and / or heterocyclic diacids; the segment units obtained by polymerization of the heterocyclic diols have the following structure (I):

[0010]

[0011] in:

[0012] R1 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution;

[0013] R2 is selected from C2-C6 pentaalkyl groups and may optionally be 1-5 halogens, nitro groups, or C2-C6 groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution;

[0014] The chain segment unit obtained after the polymerization of the heterocyclic diacid has the following structure (II):

[0015]

[0016] Where: Asp is

[0017] X is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution;

[0018] n is a non-negative integer, and the chain segment units obtained after the polymerization of heterocyclic diacids contain chain segment units with n as a positive integer.

[0019] Preferably, the segmental unit obtained by polymerization of the heterocyclic diol in the PEST material with a heterocyclic side chain has the following structure (III):

[0020]

[0021] Among them, R3 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups.

[0022] Preferably, R1 is selected from at least one of ethylene, propylidene, 1,2-phenylene or 1,2-cyclohexylene; and R2 is selected from at least one of 2-N-1,3-O-propylene or 1-N-2,3-O-propylene.

[0023] More preferably, R3 is 1,4-butylene and / or 1,4-phenylene, and R1 is 1,2-ethylene.

[0024] Preferably, in the PEST material with heterocyclic side chains, the segmental units obtained after the polymerization of the heterocyclic diacid have the following structure (IV):

[0025]

[0026] Wherein: R4 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups; preferably, X is selected from at least one of ethylene, propylene, 1,2-phenylene or 1,2-cyclohexylene; more preferably, R4 is ethylene and X is 1,2-ethylene.

[0027] Preferably, the heterocyclic diol and / or heterocyclic diacid in the PEST material with heterocyclic side chain structure account for 0.5-90 mol%, more preferably 3-50 mol%, and even more preferably 5-50 mol%.

[0028] Preferably, in the PEST material with heterocyclic side chain structure, the molar ratio of terephthalic acid to total diacid can be arbitrarily selected by those skilled in the art, for example, 20-90%, preferably 20-60% for biodegradability applications, more preferably 40-60%, and preferably 60-90% for mechanical properties applications.

[0029] In a second aspect, the present invention provides a polymer alloy comprising the PEST material with a heterocyclic side chain structure as described in any of the preceding claims.

[0030] Thirdly, the present invention provides a composition or molded article comprising the PEST material with a heterocyclic side chain structure as described in any of the preceding claims.

[0031] Fourthly, the present invention provides the use of any of the foregoing PEST materials, polymer alloys, compositions or molded articles with heterocyclic side chains, wherein the use is selected from at least one of biodegradable mulch films, paper-plastic composite films, biaxially oriented transparent barrier packaging films, biodegradable transparent tapes, and metal-coated materials.

[0032] Fifthly, the present invention provides a method for preparing a PEST material with a heterocyclic side chain structure as described in any one of the claims, comprising the following steps:

[0033] S1: Prepare heterocyclic diol and / or heterocyclic diacid monomers; the heterocyclic diol monomers have the structure shown in Formula V:

[0034]

[0035] The definitions of R1 and R2 are as described in the previous item;

[0036] The heterocyclic diacid monomer structure is shown in Formula VI:

[0037]

[0038] The definitions of Asp, X, and n are as described in the previous item;

[0039] S2: The above-mentioned heterocyclic diol and / or heterocyclic diacid monomer and terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optional other diols or diacids that can be used for polyester synthesis are subjected to esterification / transesterification reaction; or the above-mentioned heterocyclic diol and / or heterocyclic diacid monomer and prepolymer are subjected to esterification / transesterification reaction, wherein the prepolymer is obtained by esterification / transesterification reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optional other diols or diacids that can be used for polyester synthesis.

[0040] Beneficial technical effects

[0041] This invention introduces heterocyclic diols or diacids to form PEST materials with functional monomer properties. The introduction of side-chain heterocycles increases the steric hindrance of the product, improving its barrier properties. Furthermore, the imide structure enhances the product's mechanical strength and crystallization rate. Attached Figure Description

[0042] Figure 1 : NMR spectrum of 2-amino-serine alcohol functional monomer.

[0043] Figure 2 : NMR spectrum of 3-amino-serine alcohol functional monomer.

[0044] Figure 3 NMR spectrum of functional monomers of aspartic acid.

[0045] Figure 4 PEST infrared spectra of aspartic acid functional monomers modified with different proportions.

[0046] Figure 5 PEST infrared spectra of aspartic acid functional monomers modified with different proportions (partial magnification).

[0047] Figure 6 Thermal decomposition temperature of PEST modified with 5% 2-amino-serine alcohol monomer.

[0048] Figure 7 Thermal decomposition temperature of PEST modified with 10% 2-amino-serine alcohol monomer.

[0049] Figure 8 Thermal decomposition temperature of PEST modified with 15% 2-amino-serine alcohol monomer.

[0050] Figure 9 Thermal decomposition temperature of PEST modified with 20% 2-amino-serine alcohol monomer. Detailed Implementation

[0051] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0052] Unless otherwise specified, the percentages or dosage ratios in this invention are all molar percentages.

[0053] The implementation of this invention is described in detail below with reference to the definitions of terms:

[0054] I heterocyclic diol modified PEST material

[0055] The synthesis method of heterocyclic diols can be found in Chinese patent application CN202311583766.2, which first involves preparing heterocyclic diol monomers.

[0056] The structural formula of the heterocyclic diol monomer of the present invention is shown in Formula V:

[0057] in:

[0058] R1 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10cycloalkyl or C5-C 10 Aromatic group substitution;

[0059] R2 is selected from C2-C6 pentaalkyl groups and may optionally be 1-5 halogens, nitro groups, or C2-C6 groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution.

[0060] In some embodiments, R1 is selected from at least one of C2-C6 alkylene, C3-C6 cycloalkylene, or C5-C6 aromaticyl groups and may optionally be substituted with one or two halogens, nitro groups, or C2-C6 alkyl, C3-C6 cycloalkyl, or C5-C6 aromaticyl groups.

[0061] In some embodiments, R1 is selected from at least one of C2-C6 alkylene, C3-C6 cycloalkylene, or C5-C6 aromaticylene.

[0062] R2 is selected from C2-C6 pentaalkyl groups and may optionally be 1-5 halogens, nitro groups, or C2-C6 groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution.

[0063] In some embodiments, R1 is selected from at least one of ethylene, propylene, 1,2-phenylene, or 1,2-cyclohexylene.

[0064] In some embodiments, R2 is selected from at least one of 2-N-1,3-O-propyl or 1-N-2,3-O-propyl.

[0065] In some implementations, R1 is 1,2-ethylene.

[0066] In some embodiments, the heterocyclic diol monomers of the present invention can be prepared by reacting aminodiols and diacids. For example, the following representative heterocyclic diol monomers are prepared by reacting 2-amino-1,3-propanediol (2-amino-serine alcohol) or 3-amino-1,2-propanediol with succinic acid (3-amino-serine alcohol):

[0067]

[0068] In some embodiments, the heterocyclic diol of the present invention can be directly copolymerized as a monomer with other monomers to form segmental units in PEST materials through conventional polyester synthesis steps.

[0069] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-described heterocyclic diol and optionally any of the heterocyclic diacid monomers of the present invention described below, and terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optionally other diols or diacids that can be used for polyester synthesis.

[0070] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-described heterocyclic diol and optionally any of the heterocyclic diacid monomers of the present invention described below with a prepolymer, wherein the prepolymer is obtained by esterification / exchange reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optionally other diols or diacids that can be used for polyester synthesis.

[0071] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diol with terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, and ethylene glycol.

[0072] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diol and prepolymer, wherein the prepolymer is obtained by esterification / exchange reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, and ethylene glycol.

[0073] In some embodiments, the segmental units obtained after polymerization of the heterocyclic diol of the present invention have the following structure (I):

[0074] The definitions of R1 and R2 are as described above.

[0075] In some embodiments, the heterocyclic diol of the present invention forms a structure of formula (III) in the PEST material after polymerization:

[0076]

[0077] Among them, R3 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups.

[0078] In some embodiments, R3 is selected from at least one of C2-C6 alkylene, C3-C6 cycloalkylene, or C5-C6 aromaticylene.

[0079] In some embodiments, R3 is 1,4-butylene and / or 1,4-phenylene.

[0080] In some embodiments, R1 is 1,2-ethylene, R2 is selected from at least one of 2-N-1,3-O-propylene or 1-N-2,3-O-propylene, and R3 is 1,4-butylene and / or 1,4-phenylene.

[0081] In some embodiments, the heterocyclic diol accounts for 0.5-90 mol% of the modified PEST material, preferably 5-50 mol%, more preferably 5-30 mol%, for example, 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0082] II. PEST materials modified with heterocyclic diacid structure

[0083] The synthesis method of heterocyclic diacids can be found in Chinese patent application CN202311738254.9, which first involves preparing a heterocyclic diacid monomer.

[0084] The structural formula of the heterocyclic diacid monomer of the present invention is shown in Formula V:

[0085] in:

[0086] Asp is

[0087] X is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution;

[0088] n is a non-negative integer, and the chain segment units obtained after the polymerization of heterocyclic diacids contain chain segment units with n as a positive integer.

[0089] In some implementations, X is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups.

[0090] In some embodiments, X is selected from at least one of C2-C6 alkylene, C3-C6 cycloalkylene, or C5-C6 aromaticylene.

[0091] In some embodiments, X is selected from at least one of ethylene, propylene, 1,2-phenylene, or 1,2-cyclohexylene.

[0092] In some implementations, X is 1,2-ethylene.

[0093] In some embodiments, the heterocyclic diacid monomer of the present invention can be prepared by aspartic acid and a diacid. For example, a representative compound of formula IV has the following structural formula:

[0094]

[0095] wait.

[0096] In some embodiments, the heterocyclic diacid of the present invention can be directly copolymerized with other monomers to form segmental units in PEST materials through conventional polyester synthesis steps.

[0097] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diacid and optionally any of the heterocyclic diol monomers of the present invention, terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optionally other diols or diacids that can be used for polyester synthesis.

[0098] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diacid and optionally any of the aforementioned heterocyclic diol monomers with a prepolymer, wherein the prepolymer is obtained by esterification / exchange reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optionally other diols or diacids that can be used for polyester synthesis.

[0099] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diacid with terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, and ethylene glycol.

[0100] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diacid and prepolymer, wherein the prepolymer is obtained by esterification / exchange reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, and ethylene glycol.

[0101] In some embodiments, the modified PEST material of the present invention is obtained by esterification / exchange reaction of the above-mentioned heterocyclic diacid, any of the aforementioned heterocyclic diol monomers, terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, and ethylene glycol.

[0102] In some embodiments, the modified PEST material of the present invention is obtained by esterification / transesterification reaction of the above-mentioned heterocyclic diacid, any of the aforementioned heterocyclic diol monomers and prepolymers, wherein the prepolymer is obtained by esterification / transesterification reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride and ethylene glycol.

[0103] In some embodiments, the segmental units obtained after polymerization of the heterocyclic diacid of the present invention have the following structure (II):

[0104] The definitions of X and n are as described above.

[0105] In some embodiments, the heterocyclic diacid of the present invention forms a structure of formula (IV) in the PEST material after polymerization:

[0106]

[0107] Among them, R4 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups.

[0108] In some embodiments, R4 is selected from at least one of C2-C6 alkylene, C3-C6 cycloalkylene, or C5-C6 aromaticene.

[0109] In some implementations, R4 is ethylene.

[0110] In some implementations, X is 1,2-ethylene, and Asp is... R4 is ethylene, n is a non-negative integer, and n is a non-negative integer. The segment units obtained after the polymerization of heterocyclic diacids contain segment units with n as a positive integer.

[0111] In some embodiments, the heterocyclic diacid accounts for 0.5-90 mol% of the modified PEST material, preferably 5-50 mol%, for example, 1%, 2%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0112] IIIPEST materials

[0113] The PEST material of the present invention is a polymer comprising copolymer units of terephthalic acid, succinic acid and ethylene glycol, comprising repeating unit segments of formulas XI to XIII as follows:

[0114]

[0115] IV. Other diols or diacids that can be used in polyester synthesis

[0116] In some embodiments, other diols that can be used for polyester synthesis in this invention refer to at least one of alkylene glycols containing 2-18 carbon atoms, polyethylene glycol, polypropylene glycol, polytetrahydrofuran glycol, N-methyldiethanolamine, and N-ethyldiethanolamine. Other diols that can be used for polyester synthesis in this invention are preferably selected from at least one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,18-octadecanediol, polyethylene glycol, and 1,4-cyclohexanediethanol.

[0117] In some embodiments, the content of the diol used for polymer synthesis in the final PEST material with heterocyclic side chain structure can be 0-99%, for example, 0.1%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0118] In some embodiments, other dicarboxylic acids that can be used in polyester synthesis in this invention are selected from succinic acid, 2-methylsuccinic acid, 2-phenylsuccinic acid, 2-benzylmethylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2,3-diphenylsuccinic acid, 1,2-cyclosuccinic acid, 2,2,3,3-tetramethylsuccinic acid, oxalic acid, malonic acid, 1,6-adipic acid, 1,10-decanedioic acid, 1,18-octadecanoic acid, maleic acid, methylcis-butanoic acid, etc. At least one of the following: alkyl phthalate, dimethyl maleic acid, phthalic acid, hexahydrophthalic acid, norborneol alkyl phthalate, tetrahydrophthalic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-phenylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, diethylene glycol, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, 2,3-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, terephthalic acid, and 2,5-furandicarboxylic acid.

[0119] In some embodiments, the content of the diacid used for polymer synthesis in the final PEST material with heterocyclic side chain structure can be 0-99%, for example, 0.1%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0120] IV polymer alloys

[0121] The polymers of the present invention form alloys with each other or optionally with other polymers.

[0122] V polymer composition and molded body

[0123] The present invention also provides compositions or molded articles of the above-mentioned polymers, and methods for processing or molding various types of polymers are known in the art.

[0124] The polymer composition of the present invention may also contain other polymers, plasticizers, nucleating agents or hydrolysis inhibitors.

[0125] In the polymer composition of the present invention, other than those described above, fillers, flame retardants, antioxidants, lubricants, ultraviolet absorbers, antistatic agents, anti-glare agents, light stabilizers, etc., may be included as other components without impairing the effects of the present invention.

[0126] The aromatic polyester composition containing a cyclic imide structure of the present invention can be used to prepare molded bodies such as sheets by extrusion molding and pressure molding; the obtained sheets can also be further thermoformed in a temperature range above the glass transition temperature (Tg) and below the melting point (Tm) of the aromatic polyester composition containing a cyclic imide structure, for example, stretched into films or fibers.

[0127] VI. Products and Uses

[0128] The polymers, alloys thereof, or combinations thereof or molded bodies of the present invention are suitable for use in the preparation of biodegradable mulch films, paper-plastic composite films, biaxially stretched transparent barrier packaging films, biodegradable transparent tapes, metal-coated materials, etc.

[0129] The present invention will be further described in detail below through specific embodiments.

[0130] Preparation Example

[0131] Preparation Example 1: Synthesis of Aspartic Acid / Succinic Acid Modified PEST

[0132] Step 1: A five-reactor polyester synthesis apparatus was used. Two pulping reactors were preheated to 60°C, and two esterification reactors were preheated to 120°C. The modified unit synthesis monomers aspartic acid and succinic acid were added to pulping reactor 1 at a molar ratio of 1:3, along with 200 ppm of antioxidant and heat stabilizer. The mixture was slowly stirred and heated to a liquid state under a nitrogen atmosphere. The mixture was then discharged into esterification reactor 1, heated to 160°C, and held at this temperature for 3 hours (see NMR diagram for typical monomers). Figure 3 During the synthesis of functional monomers, 1,4-phthalic acid, succinic acid, and ethylene glycol were added to pulping reactor 2. (1,4-phthalic acid + succinic acid): ethylene glycol = 1:1.2. 200 ppm of antioxidant and heat stabilizer were also added. After pulping, the mixture was discharged into esterification reactor 2 and refluxed at 220°C under 400 kPa for 3 hours.

[0133] Step 2: Transfer the modified monomer from esterification vessel 1 into esterification vessel 2, add 200 ppm of anhydrous zinc acetate, and supplement with ethylene glycol. Control the ratio of glycol to diacid in the system to be 1.2:1. Raise the temperature to 225°C and continue the co-esterification reaction until more than 95% of the theoretical distillate is achieved.

[0134] Step 3: After coesterification is completed, the material is fed into the final shrinkage reactor for polycondensation reaction, and 300ppm tetrabutyl titanate is added. The vacuum degree in the reactor is slowly reduced, and the temperature is further increased to 245℃. The reaction is stopped after maintaining the vacuum degree below 20Pa for 4-6 hours. The material is discharged, water-cooled, stretched, and pelletized to obtain modified PEST polyester.

[0135] Infrared spectra of PEST polyesters modified with different proportions of aspartic acid monomer are shown below. Figures 4-5 A typical C=O bond absorption peak (1720 cm⁻¹) can be observed in the spectrum. -1 ) and CN bond absorption peak (1376 cm⁻¹) -1 The results showed that PEST polyester was successfully synthesized. When comparing different amounts of functional monomers, the CN bond absorption peak gradually increased with the increase of functional monomers, indicating that more functional monomers were successfully introduced into the material.

[0136] When the proportion of modified units exceeds 15%, the feed ratio for functional monomer preparation is aspartic acid: succinic acid = 1:1.

[0137] Preparation Example 2: Synthesis of PEST modified with serinel (2-amino-1,3-propanediol) / succinic acid

[0138] Step 1: A five-reactor polyester synthesis apparatus was used. Two pulping reactors were preheated to 60°C, and two esterification reactors were preheated to 120°C. The modified unit synthesis monomers serine and succinic acid were added to pulping reactor 1 at a molar ratio of 1:2, along with 200 ppm of antioxidant and heat stabilizer. The mixture was slowly stirred and heated to a liquid state under a nitrogen atmosphere. The mixture was then discharged into esterification reactor 1, heated to 160°C, and held at this temperature for 3 hours (see NMR diagram for typical monomers). Figure 1 The NMR spectra of the functional monomers obtained from 3-amino-serine alcohol are shown in [reference needed]. Figure 2 During the synthesis of functional monomers, 1,4-phthalic acid, succinic acid and ethylene glycol were added to pulping reactor 2, with the ratio of (1,4-phthalic acid + succinic acid): ethylene glycol = 1:1.2. 200 ppm of antioxidant and heat stabilizer were also added. After pulping, the mixture was discharged into esterification reactor 2 and refluxed at 220°C under 400 kPa for 3 hours.

[0139] Step 2: Transfer the modified monomer from esterification vessel 1 into esterification vessel 2, add 200 ppm of anhydrous zinc acetate, and supplement with ethylene glycol. Control the ratio of glycol to diacid in the system to be 1.2:1. Raise the temperature to 225°C and continue the co-esterification reaction until more than 95% of the theoretical distillate is achieved.

[0140] Step 3: After coesterification is completed, the material is fed into the final shrinkage reactor for polycondensation reaction, and 300ppm tetrabutyl titanate is added. The vacuum degree in the reactor is slowly reduced, and the temperature is further increased to 245℃. The reaction is stopped after maintaining the vacuum degree below 20Pa for 4-6 hours. The material is discharged, water-cooled, stretched, and pelletized to obtain modified PEST polyester.

[0141] Example of effect

[0142] 1. Water vapor transmission rate test standard: PEST film with a thickness of 30µm is cast using a flat vulcanizing machine. Water vapor / oxygen test conditions: 38℃, positive cup method.

[0143] 2. The tensile strength and elongation at break of the resin materials obtained in the examples and comparative examples were tested according to GB / T1040.2-2006. The melt temperature (Tm) of the resin materials obtained in the examples and comparative examples was tested according to GB / T 19466.2-2004. The melt flow index (MFI) was tested according to ASTM-D1238-2010.

[0144] 3. Thermogravimetric analysis: Turn on the TG instrument, zero the panel, and heat to an initial temperature of 60℃. Take 5g of PEST samples of different proportions, place them in a weighing crucible, and purge with nitrogen gas; slowly heat at a rate of 10℃ / min, with an endpoint temperature of 600℃; after complete weight loss, export the thermogravimetric curve for analysis.

[0145] The performance test data is shown in the table below:

[0146]

[0147] Note 1: The proportion of modified units is the molar ratio of repeating units of aspartic acid or serine functional monomers to all repeating units of the polymer.

[0148] Note 2: The terephthalic acid percentage is the proportion of terephthalic acid monomer to the total mass of the polymer. In the * group, the molar proportion of terephthalic acid is 90% of the total diacid, and in the other groups, the molar proportion of terephthalic acid is 45% of the total diacid.

[0149] As shown in the results, when the aspartic acid content is between 5% and 15%, the Rockwell hardness and impact strength of the material gradually increase with increasing aspartic acid content, reaching an optimal level at 15%. However, the elongation at break gradually decreases with increasing modifying units, which is related to the increased rigidity resulting from the introduction of more rigid imide rings. Simultaneously, the water vapor permeability and oxygen permeability indicate that the material's water vapor barrier properties and oxygen barrier properties improve with increasing proportion of modifying units.

[0150] In the serine-modified system, when the amount of modifying unit is between 5-15%, the Rockwell hardness and impact strength of the material increase with the increase of the unit addition. When the content exceeds 15%, the hardness and impact strength of the material gradually decrease. The water vapor and oxygen barrier properties gradually increase with the increase of the amount of modifying unit.

[0151] Furthermore, with the increase in the amount of functional monomers added ( Figure 6-9 The increased thermal decomposition temperature of the product indicates that the thermal stability of modified PEST increases with the increase of functional monomer content.

Claims

1. A PEST material with a heterocyclic side chain, wherein the PEST material is a polymer comprising copolymer units of terephthalic acid, succinic acid, and ethylene glycol, comprising repeating unit segments of formulas XI to XIII as follows: Its features are, The PEST material with heterocyclic side chains comprises segment units obtained by polymerization of heterocyclic diols and / or heterocyclic diacids; the segment units obtained by polymerization of the heterocyclic diols have the following structure (I): in: R1 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution; R2 is selected from C2-C6 pentaalkyl groups and may optionally be 1-5 halogens, nitro groups, or C2-C6 groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution; The chain segment unit obtained after the polymerization of the heterocyclic diacid has the following structure (II): Where: Asp is X is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups and optionally 1-5 halogens, nitro groups, or C2-C groups. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aromatic group substitution; n is a non-negative integer, and the chain segment units obtained after the polymerization of heterocyclic diacids contain chain segment units with n as a positive integer.

2. The PEST material with a heterocyclic side chain according to claim 1, wherein the segment unit obtained after polymerization of the heterocyclic diol has the following structure (III): in, R3 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups; Preferably, R1 is selected from at least one of ethylene, propylene, 1,2-phenylene, or 1,2-cyclohexylene; R2 is selected from at least one of 2-N-1,3-O-propylene or 1-N-2,3-O-propylene. More preferably, R3 is 1,4-butylene and / or 1,4-phenylene, and R1 is 1,2-ethylene.

3. The PEST material with a heterocyclic side chain according to claim 1, wherein the segment unit obtained after polymerization of the heterocyclic diacid has the following structure (IV): in: R4 is selected from C2-C 10 Alkylene, C3-C 10 Cycloalkyl or C5-C 10 At least one of the aromatic groups; preferably, X is selected from at least one of ethylene, propylene, 1,2-phenylene or 1,2-cyclohexylene; more preferably, R4 is ethylene and X is 1,2-ethylene.

4. The PEST material with a heterocyclic side chain according to claim 1, wherein the heterocyclic diol and / or heterocyclic diacid account for 0.5-90 mol% of the PEST material with a heterocyclic side chain, preferably 3-50 mol%, more preferably 5-50 mol%. More preferably, in the PEST material with heterocyclic side chain structure, terephthalic acid accounts for 20-90% of the total diacid molar ratio, more preferably 20-60%, more preferably 40-60%, and even more preferably 60-90%.

5. A polymer alloy comprising the PEST material with a heterocyclic side chain structure as described in any one of claims 1-4.

6. A composition or molded article comprising the PEST material with a heterocyclic side chain structure as described in any one of claims 1-4.

7. Use of the PEST material with heterocyclic side chain structure according to any one of claims 1-4, or the polymer alloy according to claim 5, or the composition or molded article according to claim 6, wherein the use is selected from at least one of biodegradable mulch film, paper-plastic composite film, biaxially stretched transparent barrier packaging film, biodegradable transparent tape or metal-coated material.

8. A method for preparing the PEST material with a heterocyclic side chain according to any one of claims 1-4, comprising the following steps: S1: Prepare heterocyclic diol and / or heterocyclic diacid monomers; the heterocyclic diol monomers have the structure shown in Formula V: The definitions of R1 and R2 are as described in any one of claims 1-4; The heterocyclic diacid monomer structure is shown in Formula VI: The definitions of Asp, X, and n are as described in any one of claims 1-4; S2: The above-mentioned heterocyclic diol and / or heterocyclic diacid monomer and terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optional other diols or diacids that can be used for polyester synthesis are subjected to esterification / transesterification reaction; or the above-mentioned heterocyclic diol and / or heterocyclic diacid monomer and prepolymer are subjected to esterification / transesterification reaction, wherein the prepolymer is obtained by esterification / transesterification reaction of terephthalic acid / ester / anhydride, succinic acid / ester / anhydride, ethylene glycol and optional other diols or diacids that can be used for polyester synthesis.

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