A bio-based heat-resistant film composite material and preparation method thereof

Abstract

The present disclosure relates to the technical field of polymer materials, and in particular to a bio-based heat-resistant film composite material and a preparation method thereof; the bio-based heat-resistant film comprises the following structure: a bio-based heat-resistant layer, and a bio-based barrier layer arranged on the surface of the bio-based heat-resistant layer, wherein the bio-based heat-resistant layer is a bio-based polyurethane material layer, and the bio-based barrier layer is a bio-based polyester material layer prepared using 2,5-furandicarboxylic acid as a raw material; the present disclosure uses bio-based green raw materials to prepare a film with excellent heat resistance.

Description

Technical Field

[0001] The present disclosure relates to the technical field of polymer materials, and in particular to a bio-based heat-resistant thin film composite material and a preparation method thereof. Background Art

[0002] Every aspect of human life is closely related to the polymer industry, and the level of living standards is influenced to a certain extent by the level of development of the polymer industry. However, the raw materials for the preparation of most traditional polymer materials come from non-renewable resources such as petrochemical resources, such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Their massive production and application lead to a series of resource and environmental problems. Therefore, the development of renewable resources to replace petrochemical resources is conducive to the sustainable development of the polymer industry. Currently, the bio-based monomer 2,5-furandicarboxylic acid (2,5-FDCA) can be prepared from plants such as straw, which has abundant raw material sources. The chemical structure of 2,5-FDCA is similar to that of the petroleum-based monomer terephthalic acid (TPA). It can replace TPA to a certain extent in the synthesis of polymers. This not only reduces the use of petrochemical resources, but also achieves better polymer properties. It can be seen that 2,5-FDCA has broad development prospects. Therefore, it is urgent to develop a method for preparing heat-resistant films by combining 2,5-furandicarboxylic acid and other bio-based materials. Summary of the Invention

[0003] The present disclosure provides a bio-based heat-resistant thin film composite material and a preparation method thereof to address the deficiencies in the related art.

[0004] According to a first aspect of an embodiment of the present disclosure, a bio-based heat-resistant film composite material is provided, wherein the bio-based heat-resistant film comprises the following structure: a bio-based heat-resistant layer, and a bio-based barrier layer arranged on the surface of the bio-based heat-resistant layer; wherein the bio-based heat-resistant layer is a bio-based polyurethane material layer, and the bio-based barrier layer is a bio-based polyester material layer prepared using 2,5-furandicarboxylic acid as raw material.

[0005] In one aspect of an embodiment of the present disclosure, the bio-based heat-resistant film composite material includes a first bio-based barrier layer, a bio-based heat-resistant layer, and a second bio-based barrier layer arranged in sequence from top to bottom; the first bio-based barrier layer and the second bio-based barrier layer are made of the same material, the bio-based heat-resistant layer is a bio-based polyurethane material layer, and the bio-based barrier layer is a bio-based polyester material layer prepared using 2,5-furandicarboxylic acid as raw material.

[0006] In one aspect of the embodiments of the present disclosure, the thicknesses of the first bio-based barrier layer and the second bio-based barrier layer may be the same or different.

[0007] In one aspect of the embodiment of the present disclosure, the bio-based polyurethane material layer includes a bio-based polyurethane material; the bio-based polyurethane material is obtained by polymerizing a plant oil polyol, an isocyanate, a chain extender, and a first plant extract compound.

[0008] Preferably, the vegetable oil polyol is selected from castor oil polyol, palm oil polyol, olive oil polyol, cashew nut shell oil polyol or soybean oil polyol; further preferably, the vegetable oil polyol is selected from castor oil polyol.

[0009] Preferably, the isocyanate is selected from toluene diisocyanate, dimethyl diphenyl diisocyanate, diphenylmethane diisocyanate, meta-xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate trimer, hexamethylene diisocyanate trimer, 1,4-cyclohexanedimethyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate; further preferably, the isocyanate is selected from isophorone diisocyanate.

[0010] Preferably, the chain extender is selected from 1,4-butanediol, diethylene glycol, trimethylolpropane, ethylene glycol, glycerol, 1,4-cyclohexanediol or resorcinol hydroxy ether; further preferably, the chain extender is selected from 1,4-butanediol.

[0011] In one aspect of the disclosed embodiments, the first plant extract compound is selected from salvianolic acid.

[0012] In one aspect of the embodiments of the present disclosure, the first plant extract compound is selected from salvianolic acid A, salvianolic acid B or salvianolic acid C; preferably, the first plant extract compound is selected from salvianolic acid B.

[0013] In the present disclosure, salvianolic acid B has the following structural formula: .

[0014] In one aspect of an embodiment of the present disclosure, the bio-based polyester material layer includes a bio-based polyester material obtained by polymerizing 2,5-furandicarboxylic acid, dodecanedioic acid, ethylene glycol, and a second plant extract compound. Specifically, the bio-based polyester material layer is prepared by first using 2,5-furandicarboxylic acid to produce dimethyl 2,5-furandicarboxylate, then using dodecanedioic acid to produce dimethyl dodecanedioate, and then polymerizing the dimethyl 2,5-furandicarboxylate, the dimethyl dodecanedioate, ethylene glycol, and the second plant extract compound to obtain the bio-based polyester material layer.

[0015] In one aspect of the disclosed embodiments, the second plant extract compound is selected from honokiol.

[0016] In the present disclosure, honokiol has the following structural formula: .

[0017] According to the second aspect of the embodiment of the present disclosure, a method for preparing the aforementioned bio-based heat-resistant film composite material is provided, and the method includes the following steps: Step 1-a: placing the inner layer material, the outer layer material and the middle layer material in a three-layer co-extrusion film blowing unit, and continuously heating the three-layer co-extrusion film blowing unit in different zones, and starting the main machines in the order of outer layer, middle layer and inner layer, respectively. The start-up time interval is 4-6 minutes, the set temperature of the outer layer main machine, the middle layer main machine and the inner layer main machine is 170℃-200℃, and the set temperature of the die head is 200℃-210℃; wherein, the inner layer material and the outer layer material are bio-based polyester materials, and the middle layer material is bio-based polyurethane material.

[0018] Step 2-a: Turn on the internal cooling fan, maintain the air inlet temperature at 20±2℃ and the fan frequency at 40-50Hz, pull the molten glue upward, and knead it quickly after it is formed.

[0019] Step 3-a: rolling and slitting the kneaded melt adhesive to obtain the bio-based heat-resistant film composite material.

[0020] In one aspect of the embodiments of the present disclosure, the bio-based polyurethane material is prepared by the following steps: Step 1-b: providing a vegetable oil polyol, adding the vegetable oil polyol into a reactor, heating to 75°C-85°C and performing mechanical stirring and condensation reflux, then adding isocyanate, and continuing the reaction for 2-3 hours to obtain a polyurethane prepolymer.

[0021] Step 2-b: lowering the temperature of the reactor to 60-70° C., then dissolving the first catalyst, the chain extender and the first plant extract compound in an organic solvent and adding the mixture dropwise to the reactor, and continuing the reaction for 3-4 hours.

[0022] Step 3-b: lowering the temperature of the reactor to room temperature, adding a terminator, and obtaining a bio-based polyurethane material.

[0023] In one aspect of the embodiments of the present disclosure, the bio-based polyester material is prepared by the following steps: Step 1-c: using 2,5-furandicarboxylic acid as a raw material to react with methanol to prepare 2,5-furandicarboxylic acid dimethyl ester.

[0024] Step 2-c: using dodecanedioic acid as a raw material to react with methanol to prepare dimethyl dodecanedioate.

[0025] Step 3-c: Add the prepared dimethyl dodecanedioate, dimethyl 2,5-furandicarboxylate, ethylene glycol, the second plant extract compound and the second catalyst to the reactor, and under the protection of inert gas, heat to 180°C-190°C and stir for 4-5 hours, then add the third catalyst and continue stirring for 3-4 hours to obtain the bio-based polyester material.

[0026] In one aspect of the embodiments of the present disclosure, in step 1-b, the vegetable oil polyol is selected from castor oil polyol, palm oil polyol, olive oil polyol, cashew nut shell oil polyol or soybean oil polyol. Specifically, in step 1-b, the vegetable oil polyol is selected from castor oil polyol.

[0027] In one aspect of the embodiments of the present disclosure, in step 1-b, the isocyanate is selected from toluene diisocyanate, dimethyl diphenyl diisocyanate, diphenylmethane diisocyanate, meta-xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate trimer, hexamethylene diisocyanate trimer, 1,4-cyclohexanedimethyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate. Specifically, in step 1-b, the isocyanate is selected from isophorone diisocyanate.

[0028] In one aspect of the disclosed embodiments, in step 2-b, the chain extender is selected from 1,4-butanediol, diethylene glycol, trimethylolpropane, ethylene glycol, glycerol, 1,4-cyclohexanediol, or resorcinol hydroxy ether. Specifically, in step 2-b, the chain extender is selected from 1,4-butanediol.

[0029] In one aspect of the disclosed embodiments, in step 2-b, the first catalyst is selected from dibutyltin dilaurate, stannous octoate, triethylenediamine, triethanolamine, or an aromatic amine compound. Specifically, in step 2-b, the first catalyst is selected from dibutyltin dilaurate.

[0030] In one aspect of the disclosed embodiments, in step 2-b, the first plant extract compound is selected from salvianolic acid. Specifically, in step 2-b, the first plant extract compound is selected from salvianolic acid B.

[0031] In one aspect of the disclosed embodiments, in step 2-b, the mass ratio of the first plant extract compound to the chain extender is selected from (0.15-0.25): 1. Specifically, in step 2-b, the mass ratio of the first plant extract compound to the chain extender is selected from 0.2:1.

[0032] In one aspect of the disclosed embodiments, in step 3-b, the terminator is selected from n-butanol, cyclohexanol, ethanolamine, diethanolamine, N,N-diethylamine, or N,N-dibutylamine. Specifically, in step 3-b, the terminator is selected from N,N-diethylamine.

[0033] In one aspect of the embodiments of the present disclosure, in step 3-c, the second plant extract compound is selected from honokiol.

[0034] In one aspect of the embodiments of the present disclosure, in step 3-c, the mass ratio of the second plant extract compound to ethylene glycol is selected from (0.25-0.35): 1. Specifically, in step 3-c, the mass ratio of the second plant extract compound to ethylene glycol is selected from 0.28:1.

[0035] In one aspect of the disclosed embodiments, in step 3-c, the ratio of the molar amount of ethylene glycol to the sum of the molar amounts of dimethyl dodecanedioate and dimethyl 2,5-furandicarboxylate is selected from (1.2-1.5): 1. Specifically, in step 3-c, the mass ratio of the second plant extract compound to ethylene glycol is selected from 1.35:1.

[0036] In one aspect of the embodiments of the present disclosure, in step 3-c, the molar ratio of dimethyl dodecanedioate to dimethyl 2,5-furandicarboxylate is selected from (0.8-1.2): 1. Specifically, in step 3-c, the molar ratio of dimethyl dodecanedioate to dimethyl 2,5-furandicarboxylate is selected from 1:1.

[0037] In one aspect of the embodiments of the present disclosure, in step 3-c, the second catalyst is selected from zinc acetate; and the third catalyst is selected from antimony trioxide.

[0038] In one aspect of the embodiments of the present disclosure, step 1-c is specifically as follows: 2,5-furandicarboxylic acid, methanol and concentrated sulfuric acid (catalyst) are added to a round-bottom flask equipped with a mechanical stirrer, and the mixture is refluxed at 80°C-90°C for 4-5 hours, and then the residual toluene is removed by distillation. After cooling to room temperature, the white precipitate is collected by filtration, washed several times with distilled water, and then dried in a vacuum drying oven, and purified by sublimation at 110°C-120°C to obtain pure dimethyl 2,5-furandicarboxylate.

[0039] In one aspect of the embodiments of the present disclosure, step 2-c is specifically as follows: adding dodecanedioic acid, methanol and p-toluenesulfonic acid (catalyst) to a round-bottom flask equipped with a magnetic stirrer, reflux at 90° C.-100° C. for 5-6 hours, cooling to room temperature, adding saturated sodium bicarbonate solution to neutralize the mixture until the pH value rises to 7.8-8.2; then extracting pure dodecanedioic acid dimethyl ester from the mixture with dichloromethane and water, drying the organic phase with anhydrous magnesium sulfate, and removing the solvent on a rotary evaporator to obtain dodecanedioic acid dimethyl ester.

[0040] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects: As can be seen from the above embodiments, the present disclosure uses bio-based green raw materials to prepare a thin film composite material with excellent heat resistance.

[0041] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of this application, rather than all the embodiments. The relevant embodiments described herein are illustrative and are used to provide a basic understanding of this application. The embodiments of this application should not be interpreted as limiting this application.

[0043] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0044] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0045] In the description herein, unless otherwise specified, “above” and “below” include the number itself.

[0046] Unless otherwise specified, the terms used in this disclosure have the commonly understood meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values of the various parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this disclosure).

[0047] The term "about" is used to describe and illustrate small changes. When used in conjunction with an event or situation, the term may refer to an example in which the event or situation occurs precisely and an example in which the event or situation occurs very approximately. For example, when used in conjunction with a numerical value, the term may refer to a variation range of less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. In addition, amounts, ratios, and other numerical values are sometimes presented in this article in a range format. It should be understood that such range formats are for convenience and brevity, and should be flexibly understood to include not only numerical values explicitly designated as range limits, but also all individual numerical values or subranges encompassed within the range, as if each numerical value and subrange were explicitly designated.

[0048] A list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A can contain a single component or multiple components. Item B can contain a single component or multiple components. Item C can contain a single component or multiple components.

[0049] In the present disclosure, the first plant extract compound contains at least two hydroxyl groups, which can be used together with the chain extender 1,4-butanediol to complete the chain extension of the polyurethane prepolymer, thereby being introduced into the polyurethane material to complete the modification of the polyurethane material.

[0050] In the present disclosure, the second plant extract compound also contains at least two hydroxyl groups, which can be used together with the chain extender ethylene glycol to complete the chain extension of the polyester prepolymer, thereby being introduced into the polyester material to complete the modification of the polyester material.

[0051] The present disclosure is further described below with reference to the following examples. It should be understood that these examples are only used to illustrate the present disclosure and are not intended to limit the scope of the present disclosure.

[0052] Example: Example 1: Example 1 includes the following steps: 1. Preparation of bio-based polyurethane material: Weigh 100 parts by weight of castor oil polyol, add the castor oil polyol to the reactor, heat it to 80°C and perform mechanical stirring and condensation reflux, then add 50 parts by weight of isophorone diisocyanate, continue the reaction for 2.5 hours to obtain a polyurethane prepolymer; then lower the temperature of the reactor to 60°C-70°C, then dissolve 0.25 parts by weight of the catalyst dibutyltin dilaurate, 45 parts by weight of the chain extender 1,4-butanediol and 9 parts by weight of phenolic acid B in an appropriate amount of organic solvent DMF and add them dropwise to the reactor, and continue the reaction for 3 hours; then lower the temperature of the reactor to room temperature, add 2 parts by weight of the terminator N,N-diethylamine to obtain a bio-based polyurethane material.

[0053] 2. Preparation of bio-based polyester materials: Add 78 g of 2,5-furandicarboxylic acid, 320 mL of methanol and 2 mL of concentrated sulfuric acid (catalyst) to a round-bottom flask equipped with a mechanical stirrer, reflux at 85 ° C for 5 hours, then distill off the residual toluene, cool to room temperature, filter and collect the white precipitate, wash it several times with distilled water, then place it in a vacuum drying oven to dry, and sublimate and purify it at 120 ° C to obtain pure 2,5-furandicarboxylic acid dimethyl ester.

[0054] 40 g of dodecanedioic acid, 320 mL of methanol and 4 g of p-toluenesulfonic acid (catalyst) were added to a round-bottom flask equipped with a magnetic stirrer and refluxed at 90°C for 6 hours. After cooling to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture until the pH value rose to 8.0. Pure dimethyl dodecanedioate was then extracted from the mixture with dichloromethane and water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed on a rotary evaporator to obtain dimethyl dodecanedioate.

[0055] 100 parts by weight of dimethyl 2,5-furandicarboxylate, 70 parts by weight of dimethyl dodecanedioate, 95 parts by weight of ethylene glycol, 26 parts by weight of magnolol, and 0.5 parts by weight of catalyst zinc acetate were added to a reactor. Under nitrogen protection, the temperature was raised to 180°C and stirred for 5 hours. Then, the third catalyst antimony trioxide was added and stirring was continued for 4 hours. After the reaction was completed, nitrogen was introduced to make the internal and external pressure difference consistent to obtain a bio-based polyester material.

[0056] 3. Preparation of thin film composite materials: The inner layer material, outer layer material and middle layer material are placed in a three-layer co-extrusion blown film unit, the inner layer material and outer layer material are bio-based polyester materials, and the middle layer material is a bio-based polyurethane material; the mass of the inner layer material: the mass of the outer layer material: the mass of the middle layer material = 0.3:0.3:1; the three-layer co-extrusion blown film unit is continuously heated in different zones, and the main machine start-up order is outer layer, middle layer, inner layer, respectively. The start-up time interval is 5min, the set temperature of the outer layer main machine, middle layer main machine and inner layer main machine is 180℃, the set temperature of the die head is 210℃, the internal cooling fan is turned on, the inlet air temperature is maintained at 20±2℃, the fan frequency is 50Hz, the molten glue is pulled upward, and the molten glue is quickly kneaded after being aroused. The kneaded molten glue is wound and slit to obtain the bio-based heat-resistant thin film composite material of Example 1.

[0057] Example 2: Example 2 includes the following steps: 1. Preparation of bio-based polyurethane material: Weigh 100 parts by weight of castor oil polyol, add the castor oil polyol to the reactor, heat it to 80°C and perform mechanical stirring and condensation reflux, then add 50 parts by weight of isophorone diisocyanate, continue the reaction for 2.5 hours to obtain a polyurethane prepolymer; then lower the temperature of the reactor to 60°C-70°C, then dissolve 0.25 parts by weight of the catalyst dibutyltin dilaurate, 45 parts by weight of the chain extender 1,4-butanediol and 9 parts by weight of tannic acid A in an appropriate amount of organic solvent DMF and add them dropwise to the reactor, and continue the reaction for 3 hours; then lower the temperature of the reactor to room temperature, add 2 parts by weight of the terminator N,N-diethylamine to obtain a bio-based polyurethane material.

[0058] 2. Preparation of bio-based polyester materials: Add 78 g of 2,5-furandicarboxylic acid, 320 mL of methanol and 2 mL of concentrated sulfuric acid (catalyst) to a round-bottom flask equipped with a mechanical stirrer, reflux at 85 ° C for 5 hours, then distill off the residual toluene, cool to room temperature, filter and collect the white precipitate, wash it several times with distilled water, then place it in a vacuum drying oven to dry, and sublimate and purify it at 120 ° C to obtain pure 2,5-furandicarboxylic acid dimethyl ester.

[0059] 40 g of dodecanedioic acid, 320 mL of methanol and 4 g of p-toluenesulfonic acid (catalyst) were added to a round-bottom flask equipped with a magnetic stirrer and refluxed at 90°C for 6 hours. After cooling to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture until the pH value rose to 8.0. Pure dimethyl dodecanedioate was then extracted from the mixture with dichloromethane and water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed on a rotary evaporator to obtain dimethyl dodecanedioate.

[0060] 100 parts by weight of dimethyl 2,5-furandicarboxylate, 70 parts by weight of dimethyl dodecanedioate, 95 parts by weight of ethylene glycol, 26 parts by weight of magnolol, and 0.5 parts by weight of catalyst zinc acetate were added to a reactor. Under nitrogen protection, the temperature was raised to 180°C and stirred for 5 hours. Then, the third catalyst antimony trioxide was added and stirring was continued for 4 hours. After the reaction was completed, nitrogen was introduced to make the internal and external pressure difference consistent to obtain a bio-based polyester material.

[0061] 3. Preparation of thin film composite materials: The inner layer material, outer layer material and middle layer material are placed in a three-layer co-extrusion blown film unit, the inner layer material and outer layer material are bio-based polyester materials, and the middle layer material is bio-based polyurethane material; the mass of the inner layer material: the mass of the outer layer material: the mass of the middle layer material = 0.3:0.3:1; the three-layer co-extrusion blown film unit is continuously heated in different zones, and the main machine start-up order is outer layer, middle layer, inner layer, respectively. The start-up time interval is 5min, the set temperature of the outer layer main machine, middle layer main machine and inner layer main machine is 180℃, the set temperature of the die head is 210℃, the internal cooling fan is turned on, the inlet air temperature is maintained at 20±2℃, the fan frequency is 50Hz, the molten glue is pulled upward, and the molten glue is quickly kneaded after being aroused. The kneaded molten glue is wound and slit to obtain the bio-based heat-resistant thin film composite material of Example 2.

[0062] The main difference between Example 2 and Example 1 is that Example 2 uses salvianolic acid A instead of salvianolic acid B used in Example 1.

[0063] Example 3: The steps of Example 3 are the same as those of Example 1, except that Example 3 uses salvianolic acid C instead of salvianolic acid B used in Example 1.

[0064] Example 4: Example 4 includes the following steps: 1. Preparation of bio-based polyurethane material: Weigh 100 parts by weight of castor oil polyol, add the castor oil polyol to the reactor, heat it to 80°C and perform mechanical stirring and condensation reflux, then add 50 parts by weight of isophorone diisocyanate, continue the reaction for 2.5 hours to obtain a polyurethane prepolymer; then lower the temperature of the reactor to 60°C-70°C, then dissolve 0.25 parts by weight of the catalyst dibutyltin dilaurate, 45 parts by weight of the chain extender 1,4-butanediol and 9 parts by weight of phenolic acid B in an appropriate amount of organic solvent DMF and add it dropwise to the reactor, and continue the reaction for 3 hours; then lower the temperature of the reactor to room temperature, add 2 parts by weight of the terminator N,N-diethylamine to obtain a bio-based polyurethane material.

[0065] 2. Preparation of bio-based polyester materials: Add 78 g of 2,5-furandicarboxylic acid, 320 mL of methanol and 2 mL of concentrated sulfuric acid (catalyst) to a round-bottom flask equipped with a mechanical stirrer, reflux at 85 ° C for 5 hours, then distill off the residual toluene, cool to room temperature, filter and collect the white precipitate, wash it several times with distilled water, then place it in a vacuum drying oven to dry, and sublimate and purify it at 120 ° C to obtain pure 2,5-furandicarboxylic acid dimethyl ester.

[0066] 40 g of dodecanedioic acid, 320 mL of methanol and 4 g of p-toluenesulfonic acid (catalyst) were added to a round-bottom flask equipped with a magnetic stirrer and refluxed at 90°C for 6 hours. After cooling to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture until the pH value rose to 8.0. Pure dimethyl dodecanedioate was then extracted from the mixture with dichloromethane and water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed on a rotary evaporator to obtain dimethyl dodecanedioate.

[0067] 100 parts by weight of dimethyl 2,5-furandicarboxylate, 70 parts by weight of dimethyl dodecanedioate, 95 parts by weight of ethylene glycol, 26 parts by weight of magnolol, and 0.5 parts by weight of catalyst zinc acetate were added to a reactor. Under nitrogen protection, the temperature was raised to 180°C and stirred for 5 hours. Then, the third catalyst antimony trioxide was added and stirring was continued for 4 hours. After the reaction was completed, nitrogen was introduced to make the internal and external pressure difference consistent to obtain a bio-based polyester material.

[0068] 3. Preparation of thin film composite materials: The inner layer material, outer layer material and middle layer material are placed in a three-layer co-extrusion blown film unit, the inner layer material and outer layer material are bio-based polyester materials, and the middle layer material is a bio-based polyurethane material; the mass of the inner layer material: the mass of the outer layer material: the mass of the middle layer material = 0.3:0.3:1; the three-layer co-extrusion blown film unit is continuously heated in different zones, and the main machine start-up order is outer layer, middle layer, inner layer, respectively. The start-up time interval is 5min, the set temperature of the outer layer main machine, middle layer main machine and inner layer main machine is 180℃, the set temperature of the die head is 210℃, the internal cooling fan is turned on, the inlet air temperature is maintained at 20±2℃, the fan frequency is 50Hz, the molten glue is pulled upward, and the molten glue is quickly kneaded after being aroused. The kneaded molten glue is rolled up and slit to obtain the bio-based heat-resistant thin film composite material of Example 4.

[0069] The main difference between Example 4 and Example 1 is that Example 4 uses magnolol instead of the honokiol used in Example 1.

[0070] Example 5: The steps of Example 5 are the same as those of Example 1, except that Example 5 uses an equal molar amount of catechins instead of the salvianolic acid B used in Example 1.

[0071] Example 6: The steps of Example 6 are the same as those of Example 1, except that Example 6 uses an equal molar amount of hesperetin instead of the salvianolic acid B used in Example 1.

[0072] Example 7: The steps of Example 7 are the same as those of Example 1, except that Example 7 uses an equal molar amount of chlorogenic acid instead of the salvianolic acid B used in Example 1.

[0073] Example 8: The steps of Example 8 are the same as those of Example 1, except that an equal molar amount of kaempferol is used in Example 8 instead of the salvianolic acid B used in Example 1.

[0074] Example 9: The steps of Example 9 are the same as those of Example 1, except that Example 9 uses an equal molar amount of quercetin instead of the salvianolic acid B used in Example 1.

[0075] Example 10: The steps of Example 10 are the same as those of Example 1, except that Example 10 uses an equimolar amount of ferulic acid instead of the salvianolic acid B used in Example 1.

[0076] Comparative Example 1: Comparative Example 1 includes the following steps: 1. Preparation of bio-based polyurethane material: Weigh 100 parts by weight of castor oil polyol, add the castor oil polyol to the reactor, heat it to 80°C and perform mechanical stirring and condensation reflux, then add 50 parts by weight of isophorone diisocyanate, continue the reaction for 2.5 hours to obtain a polyurethane prepolymer; then lower the temperature of the reactor to 60°C-70°C, then dissolve 0.25 parts by weight of the catalyst dibutyltin dilaurate and 50 parts by weight of the chain extender 1,4-butanediol in an appropriate amount of organic solvent DMF and add them dropwise to the reactor, and continue the reaction for 3 hours; then lower the temperature of the reactor to room temperature, add 2 parts by weight of the terminator N,N-diethylamine to obtain a bio-based polyurethane material.

[0077] 2. Preparation of bio-based polyester materials: Add 78 g of 2,5-furandicarboxylic acid, 320 mL of methanol and 2 mL of concentrated sulfuric acid (catalyst) to a round-bottom flask equipped with a mechanical stirrer, reflux at 85 ° C for 5 hours, then distill off the residual toluene, cool to room temperature, filter and collect the white precipitate, wash it several times with distilled water, then place it in a vacuum drying oven to dry, and sublimate and purify it at 120 ° C to obtain pure 2,5-furandicarboxylic acid dimethyl ester.

[0078] 40 g of dodecanedioic acid, 320 mL of methanol and 4 g of p-toluenesulfonic acid (catalyst) were added to a round-bottom flask equipped with a magnetic stirrer and refluxed at 90°C for 6 hours. After cooling to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture until the pH value rose to 8.0. Pure dimethyl dodecanedioate was then extracted from the mixture with dichloromethane and water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed on a rotary evaporator to obtain dimethyl dodecanedioate.

[0079] 100 parts by weight of dimethyl 2,5-furandicarboxylate, 70 parts by weight of dimethyl dodecanedioate, 95 parts by weight of ethylene glycol, 26 parts by weight of magnolol, and 0.5 parts by weight of catalyst zinc acetate were added to a reactor. Under nitrogen protection, the temperature was raised to 180°C and stirred for 5 hours. Then, the third catalyst antimony trioxide was added and stirring was continued for 4 hours. After the reaction was completed, nitrogen was introduced to make the internal and external pressure difference consistent to obtain a bio-based polyester material.

[0080] 3. Preparation of thin film composite materials: The inner layer material, outer layer material and middle layer material are placed in a three-layer co-extrusion blown film unit, the inner layer material and outer layer material are bio-based polyester materials, and the middle layer material is a bio-based polyurethane material; the mass of the inner layer material: the mass of the outer layer material: the mass of the middle layer material = 0.3:0.3:1; the three-layer co-extrusion blown film unit is continuously heated in different zones, and the main machine start-up order is outer layer, middle layer, inner layer, respectively. The start-up time interval is 5min, the set temperature of the outer layer main machine, middle layer main machine and inner layer main machine is 180℃, the set temperature of the die head is 210℃, the internal cooling fan is turned on, the inlet air temperature is maintained at 20±2℃, the fan frequency is 50Hz, the molten glue is pulled upward, and the molten glue is quickly kneaded after being aroused. The kneaded molten glue is wound and slit to obtain the bio-based heat-resistant thin film composite material of comparative example 1.

[0081] The main difference between Comparative Example 1 and Example 1 is that the bio-based polyurethane material in Comparative Example 1 does not include salvianolic acid.

[0082] Comparative Example 2: Comparative Example 2 includes the following steps: 1. Preparation of bio-based polyurethane material: Weigh 100 parts by weight of castor oil polyol, add the castor oil polyol to the reactor, heat to 80°C and perform mechanical stirring and condensation reflux, then add 50 parts by weight of isophorone diisocyanate, continue the reaction for 2.5 hours to obtain a polyurethane prepolymer; then lower the temperature of the reactor to 60°C-70°C, then dissolve 0.25 parts by weight of the catalyst dibutyltin dilaurate, 45 parts by weight of the chain extender 1,4-butanediol and 9 parts by weight of phenolic acid B in an appropriate amount of organic solvent DMF and add them dropwise to the reactor, and continue the reaction for 3 hours; then lower the temperature of the reactor to room temperature, add 2 parts by weight of the terminator N,N-diethylamine to obtain a bio-based polyurethane material.

[0083] 2. Preparation of bio-based polyester materials: Add 78 g of 2,5-furandicarboxylic acid, 320 mL of methanol and 2 mL of concentrated sulfuric acid (catalyst) to a round-bottom flask equipped with a mechanical stirrer, reflux at 85 ° C for 5 hours, then distill off the residual toluene, cool to room temperature, filter and collect the white precipitate, wash it several times with distilled water, then place it in a vacuum drying oven to dry, and sublimate and purify it at 120 ° C to obtain pure 2,5-furandicarboxylic acid dimethyl ester.

[0084] 40 g of dodecanedioic acid, 320 mL of methanol and 4 g of p-toluenesulfonic acid (catalyst) were added to a round-bottom flask equipped with a magnetic stirrer and refluxed at 90°C for 6 hours. After cooling to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture until the pH value rose to 8.0. Pure dimethyl dodecanedioate was then extracted from the mixture with dichloromethane and water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed on a rotary evaporator to obtain dimethyl dodecanedioate.

[0085] 100 parts by weight of dimethyl 2,5-furandicarboxylate, 70 parts by weight of dimethyl dodecanedioate, 120 parts by weight of ethylene glycol, and 0.5 parts by weight of catalyst zinc acetate were added to a reactor. Under nitrogen protection, the temperature was raised to 180°C and stirred for 5 hours. Then, the catalyst antimony trioxide was added and stirring was continued for 4 hours. After the reaction was completed, nitrogen was introduced to make the internal and external pressure difference consistent to obtain a bio-based polyester material.

[0086] 3. Preparation of thin film composite materials: The inner layer material, outer layer material and middle layer material are placed in a three-layer co-extrusion blown film unit, the inner layer material and outer layer material are bio-based polyester materials, and the middle layer material is a bio-based polyurethane material; the mass of the inner layer material: the mass of the outer layer material: the mass of the middle layer material = 0.3:0.3:1; the three-layer co-extrusion blown film unit is continuously heated in different zones, and the main machine start-up order is outer layer, middle layer, inner layer, respectively. The start-up time interval is 5min, the set temperature of the outer layer main machine, the middle layer main machine and the inner layer main machine is 180℃, the set temperature of the die head is 210℃, the internal cooling fan is turned on, the inlet air temperature is maintained at 20±2℃, the fan frequency is 50Hz, the molten glue is pulled upward, and the molten glue is quickly kneaded after being aroused. The kneaded molten glue is rolled up and slit to obtain the bio-based heat-resistant thin film composite material of comparative example 2.

[0087] The main difference between Comparative Example 2 and Example 1 is that the bio-based polyester material in Comparative Example 2 does not include magnolol.

[0088] Heat Resistance Test: The glass transition temperatures of the samples of Examples 1-10 and Comparative Examples 1-2 were tested, and the oxygen transmission rates were tested according to the method of GB / T1038-2000. The samples of Examples 1-10 and Comparative Examples 1-2 were then placed indoors for 45 days, and the glass transition temperatures of the samples of Examples 1-10 and Comparative Examples 1-2 were tested again. The test results are shown in Table 1 below.

[0089] Table 1:

[0090]

[0091] As can be seen from Table 1, the first plant extract compound contains at least two hydroxyl groups, which can be used together with the chain extender 1,4-butanediol to complete the chain extension of the polyurethane prepolymer, thereby being introduced into the polyurethane material to improve the heat resistance of the polyurethane material; this is because the molecular structure of salvianolic acid contains multiple polar groups such as phenolic hydroxyl groups and carboxyl groups. These groups can chemically react with isocyanate groups in the polyurethane molecular chain to form hydrogen bonds or chemical bonds, thereby enhancing the interaction force between the molecular chains to a certain extent, restricting the movement of the polyurethane molecular chains, thereby improving its heat resistance.

[0092] However, not all plant extract compounds containing at least two hydroxyl groups have this effect. A comparison of Examples 1-3 shows that salvianolic acid B significantly improves heat resistance compared to salvianolic acid A and salvianolic acid C. Examples 5 to 10 use a series of polyphenolic compounds from biological extracts containing multiple hydroxyl groups (catechin, hesperetin, chlorogenic acid, kaempferol, quercetin, and ferulic acid), but their improvement in heat resistance is significantly inferior to that of Example 1. In fact, the heat resistance of Examples 9 and 10 even decreased (compared to Comparative Example 1). This shows that only salvianolic acid compounds can significantly improve the heat resistance of polyurethane materials. This is because different polyphenolic compounds have different intramolecular forces. Some polyphenolic compounds do not have sufficient intramolecular forces to significantly enhance the heat resistance of polyurethane. Some polyphenolic compounds even have relatively poor thermal stability, which can affect the heat resistance of polyurethane to a certain extent.

[0093] As can be seen from Table 1, the second plant extract compound also contains at least two hydroxyl groups, which can be used together with the chain extender ethylene glycol to complete the chain extension of the polyester prepolymer, thereby being introduced into the polyester material and completing the modification of the polyester material. The magnolol molecules used in Example 1 contain multiple hydroxyl groups and benzene ring structures. These structures can interact with ester groups in the PEF molecular chain, forming hydrogen bonds or chemical bonds, thereby enhancing the tightness between the molecular chains, reducing the diffusion channels of gas molecules in the polymer matrix, and thus improving the gas barrier properties. However, the magnolol molecules used in Example 4 have similar molecular structures and properties to those used in Example 1, but their steric hindrance is different, which affects the tightness between the molecular chains. Therefore, its gas barrier performance is significantly inferior to that of Example 1; and the gas barrier properties of Comparative Example 2 are even worse. Since plant polyphenol compounds such as salvianolic acid have relatively abundant groups, they are easily oxidized, thereby reducing their heat resistance. Therefore, Example 1 with good gas barrier properties can maintain long-term heat resistance. However, the heat resistance of Example 4 decays faster, and the heat resistance of Comparative Example 2 decays even faster.

[0094] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A bio-based heat-resistant film composite material, characterized in that: The bio-based heat-resistant film composite material comprises the following structure: a bio-based heat-resistant layer, and a bio-based barrier layer disposed on the surface of the bio-based heat-resistant layer; wherein the bio-based heat-resistant layer is a bio-based polyurethane material layer, and the bio-based barrier layer is a bio-based polyester material layer prepared using 2,5-furandicarboxylic acid as raw material; The bio-based polyurethane material layer includes a bio-based polyurethane material; the bio-based polyurethane material is obtained by polymerizing a plant oil polyol, an isocyanate, a chain extender, and a first plant extract compound; The first plant extract compound is selected from salvianolic acid B, and the salvianolic acid B has the following structural formula: The bio-based polyester material layer includes a bio-based polyester material; the bio-based polyester material is obtained by polymerizing 2,5-furandicarboxylic acid, dodecanedioic acid, ethylene glycol and a second plant extract compound; The second plant extract compound is selected from honokiol, and the honokiol has the following structural formula: .

2. A method for preparing the bio-based heat-resistant film composite material according to claim 1, characterized in that: The method includes the following steps: step 1-a: placing the inner layer material, the outer layer material and the middle layer material in a three-layer co-extrusion blown film unit, and continuously heating the three-layer co-extrusion blown film unit in different zones, and starting the main machines in the order of outer layer, middle layer and inner layer, respectively. The start-up time interval is 4-6 minutes, the set temperatures of the outer layer main machine, the middle layer main machine and the inner layer main machine are 170℃-200℃, and the set temperature of the die head is 200℃-210℃; wherein, the inner layer material and the outer layer material are bio-based polyester materials, and the middle layer material is bio-based polyurethane materials; step 2-a: turning on the internal cooling fan, maintaining the inlet air temperature at 20±2℃, the fan frequency at 40-50Hz, pulling the molten glue upward, and quickly kneading the molten glue after it is aroused; step 3-a: winding and slitting the kneaded molten glue to obtain the bio-based heat-resistant film composite material.

3. The method according to claim 2, characterized in that The bio-based polyurethane material is prepared by the following steps: Step 1-b: providing a vegetable oil polyol, adding the vegetable oil polyol into a reactor, heating it to 75°C-85°C and performing mechanical stirring and condensation reflux, then adding isocyanate, and continuing the reaction for 2-3 hours to obtain a polyurethane prepolymer; Step 2-b: lowering the temperature of the reactor to 60°C-70°C, then dissolving a first catalyst, a chain extender and a first plant extract compound in an organic solvent and adding them dropwise to the reactor, and continuing the reaction for 3-4 hours; Step 3-b: lowering the temperature of the reactor to room temperature, adding a terminator, and obtaining a bio-based polyurethane material.

4. The method according to claim 3, characterized in that The method satisfies at least one of the following conditions: (1) in step 1-b, the vegetable oil polyol is selected from castor oil polyol, palm oil polyol, olive oil polyol, cashew nut shell oil polyol or soybean oil polyol; (2) in step 1-b, the isocyanate is selected from toluene diisocyanate, dimethyl diphenyl diisocyanate, diphenylmethane diisocyanate, meta-xylylene diisocyanate, tetramethylxylene diisocyanate, isophorone diisocyanate trimer, hexamethylene diisocyanate trimer, 1,4-cyclohexane dimethyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate (3) in step 2-b, the chain extender is selected from 1,4-butanediol, diethylene glycol, trimethylolpropane, ethylene glycol, propylene glycol, 1,4-cyclohexanediol or resorcinol hydroxy ether; (4) in step 2-b, the first catalyst is selected from dibutyltin dilaurate, stannous octoate, triethylenediamine, triethanolamine or aromatic amine compounds; (5) in step 2-b, the mass ratio of the first plant extract compound to the chain extender is selected from (0.15-0.25):1; (6) in step 3-b, the terminator is selected from n-butanol, cyclohexanol, ethanolamine, diethanolamine, N,N-diethylamine or N,N-dibutylamine.

5. The method according to claim 2, characterized in that The bio-based polyester material is prepared by the following steps: step 1-c: reacting 2,5-furandicarboxylic acid as a raw material with methanol to prepare 2,5-furandicarboxylic acid dimethyl ester; step 2-c: reacting dodecanedioic acid as a raw material with methanol to prepare dodecanedioic acid dimethyl ester; step 3-c: adding the prepared dodecanedioic acid dimethyl ester, 2,5-furandicarboxylic acid dimethyl ester, ethylene glycol, a second plant extract compound and a second catalyst into a reactor, heating to 180°C-190°C and stirring for 4-5 hours under the protection of inert gas, then adding a third catalyst and continuing stirring for 3-4 hours to obtain the bio-based polyester material.

6. The method according to claim 5, characterized in that The method satisfies at least one of the following conditions: (1) in step 3-c, the mass ratio of the second plant extract compound to ethylene glycol is selected from (0.25-0.35):1; (2) in step 3-c, the ratio of the molar amount of ethylene glycol to the sum of the molar amounts of dimethyl dodecanedioate and dimethyl 2,5-furandicarboxylate is selected from (1.2-1.5):1; (3) in step 3-c, the molar ratio of dimethyl dodecanedioate to dimethyl 2,5-furandicarboxylate is selected from (0.8-1.2):1; (4) in step 3-c, the second catalyst is selected from zinc acetate; and the third catalyst is selected from antimony trioxide.

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