PEF hydrogen bond reinforced modified polyester material and preparation method thereof

Abstract

The invention provides a PEF hydrogen bond reinforced modified polyester material and a preparation method thereof, and the preparation method comprises the following steps: blending 2, 5-furandicarboxylic acid and a third monomer hydroxy acid, and copolymerizing under the action of ethylene glycol to synthesize bio-based furan polyester, namely the PEF hydrogen bond reinforced modified polyester material. The introduced hydroxyl is used as a hydrogen bond donor to enhance the PEF copolyester material, so that the interaction strength and the chain stacking density between PEF chains are improved, the toughness, the melt strength and the crystallization rate of PEF can be improved by only adding a small amount of hydroxyl, and the barrier property of PEF copolyester is maintained to be more than 5 times of that of PET (Polyethylene Terephthalate).

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PEF modified copolyester materials, in particular to a PEF hydrogen bond enhanced modified polyester material and a preparation method thereof. BACKGROUND

[0002] 2,5-furan dicarboxylic acid (FDCA) derived polyesters including PEF and poly(2,5-furan dicarboxylic acid propylene glycol ester) (PPF) generally have higher glass transition temperatures (T g ) than their petroleum-based counterparts. In addition, PEF has superior stiffness, strength, and higher gas barrier properties than PET, with O2 and CO2 permeability reduced by 5-11 times and 2-19 times, respectively, compared to PET. Furthermore, PEF production is expected to reduce greenhouse gas emissions by 45-55% and non-renewable energy use by about 40-50% compared to PET. Due to excellent sustainability and superior thermo-mechanical and gas barrier properties, PEF is an excellent substitute for PET in the future, with great application potential and market prospects.

[0003] Due to the backbone rigidity of PEF, its crystallinity is low and the crystallization rate is slow, it is difficult to induce crystallization by stretching, and the processing is difficult. In addition, there are also problems such as brittleness, strong rigidity and insufficient toughness, which must be overcome before its successful industrial application. PEF can be modified by copolymerization, and even by biaxial stretching orientation. For example, block or random copolymerization is also an effective method to improve the toughness of PEF: poly(ethylene glycol-co-1,4-cyclohexyl-2,5-furan dicarboxylate) (PECF) containing 32-76 mol% of 1,4-cyclohexyl-2,5-furan dicarboxylate units improves the elongation at break (50-186%) and maintains a fairly good tensile strength (71-59 MPa) and modulus (2.2-1.7 GPa), but due to the destruction of the regularity of the PEF polyester chain, the interaction strength between the PEF copolyester chains and the chain packing density are reduced, and the gas barrier property is reduced.

[0004] Therefore, how to improve the toughness of PEF while maintaining or even further improving the excellent barrier property of PEF is of great significance for developing the performance of PEF polyester materials and broadening its application. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a PEF hydrogen bond enhanced modified polyester material and a preparation method thereof, which solves the problem that the existing PEF modified polyester material cannot simultaneously consider toughness and barrier property.

[0006] In order to achieve the above-mentioned and other related purposes, the present application provides a preparation method of PEF hydrogen bond enhanced modified polyester material, 2,5-furan dicarboxylic acid is blended with a third monomer hydroxy acid, and then copolymerized into a bio-based furan polyester under the action of ethylene glycol, that is, the PEF hydrogen bond enhanced modified polyester material.

[0007] In the above technical scheme of the present application, a PEF copolyester material with enhanced toughness, melt strength and barrier performance is provided by copolymerization of a third monomer. The technical concept of the present application is to introduce a third monomer containing a hydroxyl group based on 2,5-furan dicarboxylic acid (FDCA) as the core, and to modify it without destroying the regularity of the PEF chain. A bio-based furan polyester is synthesized by copolymerization of the third monomer hydroxy acid, FDCA and ethylene glycol (EG), thereby introducing additional hydrogen bonds into PEF and improving the performance of PEF by utilizing the hydrogen bond effect. By designing and synthesizing the structure and hydrogen bond form of the third monomer, a third monomer structure that does not destroy the regularity of the PEF chain and meets the requirements of food safety application is obtained. After adding, the crystallization speed of PEF and the packing density between PEF chains are improved, thereby improving the performance of PEF and enhancing its toughness and crystallization speed. The present application explores the influence law and application of hydrogen bonds on the barrier performance of polyester materials, which can guide the subsequent modification direction of PEF and the development of high-performance materials, and realize sustainable development.

[0008] Preferably, the third monomer hydroxy acid is selected from one or more of 5-hydroxy isophthalic acid (5-HIPA), 2,5-hydroxy terephthalic acid, 5-hydroxy isophthalic acid dimethyl ester, 5-carboxy vanillic acid, 4,5-dihydroxy isophthalic acid and 4,5,6-trihydroxy isophthalic acid.

[0009] Preferably, the molar ratio of 2,5-furan dicarboxylic acid to third monomer hydroxy acid is (90-99.5):(0.5-10).

[0010] Preferably, the molar ratio of the total moles of 2,5-furan dicarboxylic acid and third monomer hydroxy acid to the ethylene glycol is 1:(1.2-1.5).

[0011] Preferably, at least one of a complex catalyst, an antioxidant and an ether stabilizer is also added to the copolymerization system.

[0012] Preferably, the complex catalyst is a mixture of at least two of germanium oxide, antimony trioxide, aluminum trioxide, zinc acetate, titanium isopropyl alcohol and stannous octoate.

[0013] The antioxidant is selected from one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] spirocyclopentane ester, tris(2,4-di-tert-butylphenyl) phosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester, and dilauryl thiodipropionate.

[0014] More preferably, the antioxidant is a mixture of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] spirocyclopentane ester and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1, i.e., antioxidant B215.

[0015] Preferably, the anti-ether stabilizer is selected from one or more of phosphoric acid, trimethyl phosphate, and triphenyl phosphate.

[0016] Preferably, the molar ratio of the total moles of 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the complex catalyst is 1:(0.0001-0.0002).

[0017] Preferably, the molar ratio of the total moles of 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the antioxidant is 1:(0.0001-0.001).

[0018] Preferably, the molar ratio of the total moles of 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the anti-ether stabilizer is 1:(0.00001-0.0001).

[0019] Preferably, the complex catalyst is a mixture of germanium oxide and antimony trioxide in a molar ratio of 110:50, more preferably 110 ppm:50 ppm.

[0020] The copolymerization synthesis process includes beating, esterification, polycondensation, and pelletizing.

[0021] More preferably, the complex catalyst, the antioxidant, and the anti-ether stabilizer are also added to the copolymerization synthesis system, and the specific order of addition is as follows: first, mix the 2,5-furan dicarboxylic acid and the third monomer hydroxy acid, then sequentially add the complex catalyst, the antioxidant, ethylene glycol, and the anti-ether stabilizer, and then beat.

[0022] Preferably, the beating is carried out in a closed condition with a protective atmosphere, specifically using a reaction kettle with a N2 atmosphere.

[0023] Preferably, the esterification temperature is 160-195°C, and the pressure is 35-56 kPa.

[0024] Preferably, the polycondensation reaction includes pre-polycondensation and final polycondensation, the pre-polycondensation is carried out at 200-235°C and a vacuum degree of 10 -1The final polycondensation is carried out at 255-262℃ and 80-200 Pa, preferably 80 Pa, to remove the excess ethylene glycol, and finally the melt viscosity of the product is about 0.6-0.9 dl / g.

[0025] The synthesis route of the PEF hydrogen bond enhanced modified polyester material of the present application is shown as follows (taking 5-HIPA as an example):

[0026] .

[0027] The present application also provides a PEF hydrogen bond enhanced modified polyester material prepared by the above preparation method.

[0028] As described above, the PEF hydrogen bond enhanced modified polyester material and the preparation method thereof of the present application have the following beneficial effects:

[0029] (1) The third monomer hydroxy acid used in the present application is a mature commercial product, which is economical and inexpensive.

[0030] (2) The preparation process is simple, and can be realized by simply adjusting the parameters on the existing mature equipment, which is low in cost.

[0031] (3) The introduced hydroxyl group as a hydrogen bond donor enhances the PEF copolyester material, improves the interaction strength and chain packing density between PEF chains, and only a small amount of addition can realize the improvement of the toughness, melt strength and crystallization rate of PEF, and the barrier property of the PEF copolyester is maintained at more than 5 times of that of PET.

[0032] (4) The influence rule and application of hydrogen bond on the barrier property of polyester material are explored, and the modification method of PEF is developed, which guides the subsequent development of modified materials that can realize high barrier property with a small amount of addition.

[0033] (5) Under the market situation of about 200,000 yuan per ton of bio-based PEF raw materials, it is conducive to economic sustainable development and environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The chemical structural formula and corresponding nuclear magnetic spectrum (the serial numbers of different peaks in the nuclear magnetic spectrum correspond to the chemical structure and position of the product) of the products obtained in Examples 1-6 and Comparative Example 1 are shown: A is the structure analysis of 0.5% 5-HIPA copolymerization product; B is the superimposed hydrogen spectrum of the characteristic signal region of the PEF hydrogen bond enhanced modified polyester material prepared by different proportions of 5-HIPA in Examples 1-6.

[0035] Figure 2Fourier transform infrared spectra of the products obtained in Examples 1 to 6 and Comparative Example 1 are shown: hydroxyl (A: 5-hydroxyisophthalic acid), oxygen-methylene-oxygen (O-CH2-CH2-O) stretching vibration (B: ethylene glycol), aromatic ring-aromatic ring-carbonyl (C: 2,5-furandicarboxylic acid) and methylene (CH) stretching vibration (D: 2,5-furandicarboxylic acid and 5-hydroxyisophthalic acid).

[0036] Figure 3 X-ray diffraction patterns (A) of the products obtained in Examples 2 to 4 and Comparative Example 1 and differential scanning calorimetry (DSC) isothermal crystallization curves (B) of the products obtained in Examples 1 to 6 and Comparative Example 1 at 160°C are shown.

[0037] Figure 4 Characterization of the thermal properties of the copolyesters is shown: thermal stability as a function of 5-hydroxyisophthalic acid (5-HIPA) content determined by thermogravimetric analysis (TGA) (A); glass transition temperature (Tg) of the products obtained in Examples 1 to 6 and Comparative Example 1 as a function of 5-HIPA content determined by differential scanning calorimetry (DSC) heating curves (B).

[0038] Figure 5 Pictures of the cladding transparency effect of the product obtained in Example 7 after being blown into a thin film are shown.

[0039] Figure 6 Pictures of the bending test of the product obtained in Example 2 are shown: upper picture before bending, lower picture after bending. DETAILED DESCRIPTION

[0040] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is contemplated that alterations and modifications of the herein disclosed embodiment can readily occur to those skilled in the art. It is intended that the following claims be construed to cover all such alterations and modifications as fall within the true spirit and scope of the present application. Various embodiments of the application have been described in fulfillment of the various objects of the application. It should be recognized that these embodiments are merely illustrative of the principles of the present application. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present application.

[0041] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. As used herein and in the following claims, the term "excluding" has the normal meaning found in the dictionary but also can mean "consisting essentially of" or "consisting of", unless otherwise noted.

[0042] Furthermore, it should be understood that the combination of one or more steps of the methods mentioned in the present application does not exclude that other steps of the methods can exist before and after the mentioned combination steps or other steps of the methods can be inserted between the explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination of one or more devices / apparatuses mentioned in the present application does not exclude that other devices / apparatuses can exist before and after the mentioned combination devices / apparatuses or other devices / apparatuses can be inserted between the explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of the steps of the methods is only a convenient tool to identify the steps of the methods, and is not intended to limit the arrangement order of the steps of the methods or to restrict the scope of the application, and the change or adjustment of the relative relationship, without substantial change of the technical content, is also regarded as the scope of the application that can be implemented.

[0043] Example 1

[0044] The present embodiment provides a preparation method of a PEF hydrogen bond enhanced modified polyester material, comprising the following steps:

[0045] After 0.5 mol% of 5-hydroxyisophthalic acid (5-HIPA: 3.6 g, 0.02 mol) is fully mixed with 99.5 mol% of 2,5-furandicarboxylic acid FDCA (497.5 g, 3.18 mol), 120 ppm of germanium oxide and 40 ppm of antimony trioxide, 500 ppm of antioxidant B215 which is a mixture of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1 are uniformly mixed; 20 ppm of triethyl phosphate anti-ether stabilizer is dissolved in 4 mol of ethylene glycol EG;

[0046] At room temperature, the above two materials are added to a 2.5 L reaction kettle and fully stirred for half an hour, during which the gas atmosphere in the reaction kettle is replaced three times using inert gas, and the esterification reaction is carried out under the conditions of a reaction kettle temperature of 160-195°C and a pressure of 35-56 kPa; after the water output calculation esterification rate exceeds 90%, pre-polycondensation is carried out;

[0047] Pre-polycondensation is carried out at 230°C and slow vacuum extraction to a vacuum degree of 10 -1 kPa, the reaction time is 50 min; the final polycondensation reaction is carried out at a polycondensation temperature of 255-262°C and a vacuum degree of 80-200 Pa, the induction period is 60 min, and the polycondensation time is 27 min; after the stirring paddle torque reaches the expectation, the stirring is stopped, and a polymer melt with a viscosity of about 0.647 dl / g is obtained;

[0048] The polymer melt is sent to a granulator by pressure for cooling, granulation, drying to obtain a bio-based furan polyester, i.e. the PEF hydrogen bond enhanced modified polyester material, recorded as PEHIF. 0.5 .

[0049] The chemical structure and nuclear magnetic hydrogen spectrum of the product obtained in Example 1 are characterized as shown in Figure 1 The obtained product is a random copolymer, and the content of 5-HIPA is 0.5%, which is consistent with the feeding amount. The chemical structure corresponding to each signal peak is marked with the same letter by nuclear magnetic analysis.

[0050] Example 2

[0051] The present example provides a preparation method of a PEF hydrogen bond enhanced modified polyester material, comprising the following steps:

[0052] After 1 mol% of 5-hydroxyisophthalic acid (5-HIPA) (7.2 g, 0.04 mol) and 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol) are mixed, 120 ppm of germanium oxide and 40 ppm of antimony trioxide, 500 ppm of antioxidant B215 are added and uniformly mixed, the antioxidant B215 is a mixture of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1; 20 ppm of triethyl phosphate anti-ether stabilizer is dissolved in 4 mol of EG;

[0053] At room temperature, the above two materials are added to a 2.5 L reaction kettle and stirred for half an hour, during which the gas atmosphere in the reaction kettle is replaced three times with inert gas, and the esterification reaction is carried out under the conditions of a reaction kettle temperature of 160-195°C and a pressure of 35-56 Kpa; after the water output calculation esterification rate is more than 90%, pre-polycondensation is carried out;

[0054] The pre-polycondensation is carried out at 230°C and under slow vacuum conditions, and the excess ethylene glycol is removed, and the reaction time is 50 min; the final polycondensation reaction is carried out at a polycondensation temperature of 255-262°C and under vacuum, and the induction period is 60 min, and the polycondensation time is 25 min; after the stirring paddle torque reaches the expectation, the stirring is stopped, and a melt with a viscosity of about 0.671 dl / g is obtained;

[0055] The polymer melt is sent to a granulator by pressure for cooling, granulation, drying to obtain a bio-based furan polyester, i.e. the PEF hydrogen bond enhanced modified polyester material, recorded as PEHIF-1.

[0056] The bending test diagram of the product obtained in Example 2 is as shown in Figure 6The upper figure shows the state before bending, and the lower figure shows the state after bending.

[0057] Example 3

[0058] The present example provides a method for preparing a PEF hydrogen bond enhanced modified polyester material, comprising the following steps:

[0059] After 2 mol% of 5-hydroxyisophthalic acid (5-HIPA) (14.4 g, 0.08 mol) is fully mixed with 98 mol% of 2,5-furan dicarboxylic acid FDCA (490 g, 3.12 mol), the subsequent steps are the same as in Example 2, the polycondensation time is 22 min, and the stirring is stopped after the stirring paddle torque reaches the expected value, to obtain a melt with a viscosity of about 0.675 dl / g; the polymerization melt is sent to a granulator by pressure for cooling, granulation, and drying; a bio-based furan polyester is prepared, which is a PEF hydrogen bond enhanced modified polyester material.

[0060] Example 4

[0061] The present example provides a method for preparing a PEF hydrogen bond enhanced modified polyester material, comprising the following steps:

[0062] After 3 mol% of 5-hydroxyisophthalic acid (5-HIPA) (21.6 g, 0.12 mol) is fully mixed with 97 mol% of 2,5-furan dicarboxylic acid FDCA (485 g, 3.10 mol), the subsequent steps are the same as in Example 2, the polycondensation time is 20 min, and the stirring is stopped after the stirring paddle torque reaches the expected value, to obtain a melt with a viscosity of about 0.715 dl / g; the polymerization melt is sent to a granulator by pressure for cooling, granulation, and drying; a bio-based furan polyester is prepared, which is a PEF hydrogen bond enhanced modified polyester material, denoted as PEHIF-3.

[0063] Example 5

[0064] The present example provides a method for preparing a PEF hydrogen bond enhanced modified polyester material, comprising the following steps:

[0065] After 4 mol% of 5-hydroxyisophthalic acid (28.8 g, 0.16 mol) is fully mixed with 96 mol% of 2,5-furan dicarboxylic acid FDCA (480 g, 3.07 mol), the subsequent steps are the same as in Example 2, the polycondensation time is 20 min, and the stirring is stopped after the stirring paddle torque reaches the expected value, to obtain a melt with a viscosity of about 0.658 dl / g; the polymerization melt is sent to a granulator by pressure for cooling, granulation, and drying; a bio-based furan polyester is prepared, which is a PEF hydrogen bond enhanced modified polyester material, denoted as PEHIF-4.

[0066] Example 6

[0067] This embodiment provides a method for preparing a PEF hydrogen bond reinforced modified polyester material, including the following steps:

[0068] After thoroughly mixing 5 mol% 5-hydroxyisophthalic acid (5-HIPA) (36 g, 0.20 mol) with 95 mol% 2,5-furandicarboxylic acid FDCA (480 g, 3.04 mol), the subsequent steps were the same as in Example 2. The polycondensation time was 22 min. Stirring was stopped after the stirring paddle torque reached the expected value, resulting in a melt with a viscosity of approximately 0.799 dl / g. The polymerized melt was fed to a pelletizer under pressure for cooling, pelletizing, and drying. The resulting bio-based furan polyester, namely the PEF hydrogen bond reinforced modified polyester material, was designated PEEIF-5.

[0069] Example 7

[0070] After thoroughly mixing 7 mol% 5-hydroxyisophthalic acid (5-HIPA) (50.4 g, 0.28 mol) with 93 mol% 2,5-furandicarboxylic acid FDCA (465 g, 2.97 mol), the subsequent steps were the same as in Example 2. The polycondensation time was 20 min. Stirring was stopped after the stirring paddle torque reached the expected value, resulting in a melt with a viscosity of approximately 0.835 dl / g. The polymerized melt was fed to a pelletizer under pressure for cooling, pelletizing, and drying. The resulting bio-based furan polyester, namely the PEF hydrogen bond reinforced modified polyester material, is designated as PEEIF-7.

[0071] The morphological image of the product obtained in this embodiment after being blown into a film is shown below. Figure 5 As shown, the film thickness is 0.01 mm and the light transmittance is 94%, which allows the material covered by the film to be seen clearly, meeting the application requirements of packaging materials and some optical films.

[0072] Example 8

[0073] After thoroughly mixing 10 mol% 5-hydroxyisophthalic acid (5-HIPA) (72 g, 0.40 mol) and 90 mol% 2,5-furandicarboxylic acid FDCA (450 g, 2.88 mol), the subsequent steps were the same as in Example 2. The polycondensation time was 20 min, and stirring was stopped after the stirring paddle torque reached the expected value, resulting in a melt with a viscosity of approximately 0.891 dl / g. The polymerized melt was fed to a pelletizer under pressure for cooling, pelletizing, and drying, thus obtaining a bio-based furan polyester, which is a PEF hydrogen bond reinforced modified polyester material.

[0074] Example 9

[0075] After 1 mol% of 2,5-hydroxyterephthalic acid (0.40 mol) was mixed with 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol), the subsequent steps were the same as Example 2, the polycondensation time was 25 min, and the stirring was stopped after the stirring paddle torque reached the expectation, to obtain a melt with a viscosity of about 0.837 dl / g; the polymerization melt was sent to the granulator by pressure for cooling, granulation, and drying; and a bio-based furan polyester, i.e., a PEF hydrogen bond enhanced modified polyester material, was prepared.

[0076] Example 10

[0077] After 1 mol% of 5-hydroxyisophthalic acid dimethyl ester (0.40 mol) was mixed with 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol), 100 ppm of zinc acetate was additionally added as a third component of the catalyst, the subsequent steps were the same as Example 2, the polycondensation time was 25 min, and the stirring was stopped after the stirring paddle torque reached the expectation, to obtain a melt with a viscosity of about 0.689 dl / g; the polymerization melt was sent to the granulator by pressure for cooling, granulation, and drying; and a bio-based furan polyester, i.e., a PEF hydrogen bond enhanced modified polyester material, was prepared.

[0078] Example 11

[0079] After 1 mol% of 5-carboxyvanillic acid (0.40 mol) was mixed with 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol), the subsequent steps were the same as Example 2, the polycondensation time was 25 min, and the stirring was stopped after the stirring paddle torque reached the expectation, to obtain a melt with a viscosity of about 0.737 dl / g; the polymerization melt was sent to the granulator by pressure for cooling, granulation, and drying; and a bio-based furan polyester, i.e., a PEF hydrogen bond enhanced modified polyester material, was prepared.

[0080] Example 12

[0081] After 1 mol% of 4,5-dihydroxyisophthalic acid (0.40 mol) was mixed with 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol), the subsequent steps were the same as Example 2, the polycondensation time was 25 min, and the stirring was stopped after the stirring paddle torque reached the expectation, to obtain a melt with a viscosity of about 0.674 dl / g; the polymerization melt was sent to the granulator by pressure for cooling, granulation, and drying; and a bio-based furan polyester, i.e., a PEF hydrogen bond enhanced modified polyester material, was prepared.

[0082] Example 13

[0083] After 1 mol% of 4,5,6-trihydroxyisophthalic acid (0.40 mol) was mixed with 99 mol% of 2,5-furan dicarboxylic acid FDCA (495 g, 3.17 mol), the subsequent steps were the same as Example 2, the polycondensation time was 25 min, and the stirring torque reached the expected value, and the stirring was stopped, and a melt with a viscosity of about 0.653 dl / g was obtained; the polymerization melt was sent to the granulator by pressure for cooling, granulation, drying; and a bio-based furan polyester, i.e., a PEF hydrogen bond enhanced modified polyester material, was prepared

[0084] Comparative Example 1

[0085] Comparative Example 1 and Example 1 differ in that 5-hydroxyisophthalic acid (5-HIPA) is not added, including the following steps:

[0086] 2,5-furan dicarboxylic acid FDCA (500 g, 3.2 mol) and a total of 160 ppm of a compounded catalyst and 500 ppm of an antioxidant were uniformly mixed; 20 ppm of an ether stabilizer was dissolved in 4 mol of EG;

[0087] At room temperature, the above two materials were added to a 2.5 L reaction kettle and stirred for half an hour, during which the reaction kettle was replaced with inert gas three times. The esterification reaction was carried out at a reaction kettle temperature of 160-195°C and a pressure of 35-56 Kpa, and the pre-polycondensation was carried out after the water output calculation esterification rate was more than 90% at 200-235°C and slow vacuum. The reaction time was 50 min; the final polycondensation reaction was carried out at a polycondensation temperature of 255-262°C and under vacuum, with an induction period of 60 min and a polycondensation time of 27 min; the stirring torque reached the expected value, and the stirring was stopped, and a melt with a viscosity of about 0.622 dl / g was obtained; the polymerization melt was sent to the granulator by pressure for cooling, granulation, drying, and a polyester material was prepared, which was recorded as PEHIF-0.

[0088] The nuclear magnetic resonance superimposed spectrum of Comparative Example 1 and Examples 1-6 is shown in Figure 1 The characteristic region representing the content of 5-HIPA is enlarged, and the content calculated by nuclear magnetic resonance is consistent with the feeding amount.

[0089] The properties of the materials prepared in each example and Comparative Example 1 were tested:

[0090] Nuclear magnetic resonance (NMR): hydrogen spectrum was determined at room temperature on a 400 megahertz nuclear magnetic resonance instrument (Bruker, Germany) with deuterated trifluoroacetic acid (in hydrogen spectrum, its chemical shift δ = 11.5 ppm) as the solvent.

[0091] Thermogravimetric analysis (TGA): TA Q500 thermogravimetric analyzer from TA Instruments was used for the test. According to GB / T 19466.6-2009, all samples were heated from 30℃ to 600℃ at a heating rate of 10℃ / min under nitrogen atmosphere.

[0092] Differential scanning calorimetry (DSC): DSC analysis was performed using TA-Q2000 thermal analyzer. According to GB / T 19466.3-2004, the heating rate was 10℃ / min.

[0093] X-ray diffraction (XRD): XRD analysis was performed using Ultima IV instrument; test angle: wide angle 5 - 90°, regular test rate: 5° / min.

[0094] Melt index (MFI) test: Melt index was tested using RL1100 melt index tester according to GB / T 3682 at 260℃.

[0095] The chemical structure and NMR spectrum of the product obtained in Examples 1-6 and Comparative Example 1 are shown in Figure 1 , wherein the letters marked in the chemical structure correspond to the peaks marked in Figure 1 , and the structure and position of the product corresponding to the English lowercase serial number of different peaks in the NMR spectrum can be seen from Figure 1 It can be seen that when the third monomer hydroxy acid participates in copolymerization, the hydroxyl group does not participate in the reaction, and by adding different proportions of the third monomer hydroxy acid, PEF copolyester materials with different enhanced hydrogen bond contents are obtained.

[0096] The Fourier transform infrared spectrum of the product obtained in Examples 1-6 and Comparative Example 1 is shown in Figure 2 , and it can be seen from Figure 2 that the hydroxyl group (A: 5-hydroxyisophthalic acid), the oxygen-methylene-oxygen (O-CH2-CH2-O) stretching vibration (B: ethylene glycol), the aromatic ring-aromatic ring-carbonyl (C: 2,5-furandicarboxylic acid) and the methylene (CH) stretching vibration (D: 2,5-furandicarboxylic acid and 5-hydroxyisophthalic acid).

[0097] The X-ray diffraction spectrum of the product obtained in Examples 2-4 and Comparative Example 1 is shown in Figure 3 , and the isothermal crystallization curve of the product obtained in Examples 1-6 and Comparative Example 1 at 160℃ by differential scanning calorimetry (DSC) is shown in Figure 3 .

[0098] The thermal stability determined by thermogravimetric analysis (TGA) with the change of the content of 5-hydroxyisophthalic acid (5-HIPA) is as follows:Figure 4 The glass transition temperature (Tg) of the product obtained in Examples 1-6 and Comparative Example 1 as a function of the 5-HIPA content is shown in Figure 1 by the DSC heating curve. Figure 4

[0099] The results are shown in Table 1:

[0100] Table 1. Composition structure and performance data of the materials prepared in Examples 1-8 and Comparative Example 1

[0101]

[0102] In Table 1, [η] is the intrinsic viscosity of the product; Xc (%) is the crystallinity; p s is the product density; T g is the glass transition temperature; T d is the initial decomposition temperature.

[0103] The materials prepared in Examples 1-8 and Comparative Example 1 were injection molded into standard bars, and the corresponding mechanical properties were tested according to the national standard. The tensile and bending performance tests were carried out according to GB / T 1040 2006, wherein the tensile rate for the tensile performance test was 50 mm / min, and the test environment temperature was 11 ℃;

[0104] The gas permeability test was tested according to the national standard GB / T 1038-2022, and the results are shown in Table 2:

[0105] Table 2. Mechanical properties and barrier properties data of the materials prepared in Examples 1-6 and Comparative Example 1

[0106]

[0107] As can be seen from Table 1 and Table 2, by comparing the elongation at break of the materials prepared in Examples 1-8 and Comparative Example 1, it is found that the elongation at break is increased from about 5% (Comparative Example 1) to more than 11% (Example 2) after modification by the present application, and the toughness is significantly improved; the melt index is reduced from 94.6 g / (10 min) (Comparative Example 1) to 12.35 g / (10 min) (Example 8), and the melt strength is increased; the gas barrier property is still maintained to be more than 5 times (Examples 3-4) of that of PET (oxygen permeability coefficient is about: 0.0597 ml(g)·mm / m 2 d·MPa), and especially when the addition amount is 1% and 2%, the gas barrier property of the copolyester is improved compared to pure PEF. And the crystallization rate is increased with the increase of the content of 5-HIPA, which is beneficial to accelerate crystallization during processing, and the thermal stability is improved, and the glass transition temperature is maintained above 80 ℃.

[0108] ​The foregoing examples are to be construed as merely illustrative of the presently disclosed embodiments, and do not exhaust the scope of the present application. Furthermore, various modifications to both the examples listed herein and the methods and compositions of the application will be apparent to those skilled in the art, and this application is intended to encompass such modifications within the scope and spirit of the application. Although the application has been described in conjunction with specific preferred embodiments thereof, it will be understood that the application is not limited to these embodiments. In fact, various modifications to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments. Therefore, to the extent that modifications of the described embodiments incorporating some but not other features of the application are within the spirit and scope of the application, they should be and are intended to be included within the scope of the application.

Claims

1. A method for producing a PEF hydrogen bond-enhancing modified polyester material, characterized in that, The 2,5-furan dicarboxylic acid is blended with a third monomer hydroxy acid, and then copolymerized with ethylene glycol to synthesize a bio-based furan polyester, i.e. a PEF hydrogen bond enhanced modified polyester material.

2. The method of claim 1, wherein: The third monomer hydroxy acid is selected from one or more of 5-hydroxy isophthalic acid, 2,5-hydroxy terephthalic acid, 5-hydroxy isophthalic acid dimethyl ester, 5-carboxy vanillic acid, 4,5-dihydroxy isophthalic acid, and 4,5,6-trihydroxy isophthalic acid.

3. The method of claim 2, wherein: The molar ratio of the 2,5-furan dicarboxylic acid to the third monomer hydroxy acid is (90-99.5):(0.5-10).

4. The method of claim 1, wherein: The molar ratio of the total moles of the 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the ethylene glycol is 1:(1.2-1.5).

5. The method of claim 1, wherein: In the copolymerization system, at least one of a compounded catalyst, an antioxidant, and an ether stabilizer is also added; the compounded catalyst is a mixture of at least two of germanium oxide, antimony trioxide, aluminum trioxide, zinc acetate, titanium isopropoxide, and stannous octoate; the antioxidant is selected from one or more of tetra [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl ester, and dilauryl thiodipropionate; and the ether stabilizer is selected from one or more of phosphoric acid, trimethyl phosphate, and triphenyl phosphate.

6. The method of claim 5, wherein: The molar ratio of the total moles of the 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the compounded catalyst is 1:(0.0001-0.0002); the molar ratio of the total moles of the 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the antioxidant is 1:(0.0001-0.001); and the molar ratio of the total moles of the 2,5-furan dicarboxylic acid and the third monomer hydroxy acid to the ether stabilizer is 1:(0.00001-0.0001).

7. The method of claim 6, wherein: The compounded catalyst is a mixture of germanium oxide and antimony trioxide in a molar ratio of 110:

50.

8. The method of claim 1, wherein: The copolymerization reaction includes beating, esterification, polycondensation, and pelletizing.

9. The method of claim 8, wherein: The beating is carried out in a closed condition with a protective atmosphere; the temperature of the esterification reaction is 160-195°C, and the pressure is 35-56 kPa; the polycondensation reaction includes a pre-polycondensation reaction and a final polycondensation reaction, the pre-polycondensation is carried out at 200-235°C and a vacuum degree of 10 -1 kPa; the final polycondensation reaction is carried out at 255-262°C and a vacuum degree of 80-200 Pa, to obtain a melt with a viscosity of about 0.6-0.9 dl / g.

10. A PEF hydrogen bond enhanced modified polyester material prepared by the preparation method of any one of claims 1-9.

Images