Liquid crystalline polyester-amide-imides based on bio-based di-amine and their preparation and use

Abstract

The application relates to a liquid crystal polyester-amide-imide based on a bio-based diamine and preparation and application thereof, the liquid crystal polyester-amide-imide disclosed by the application takes bio-based monomers as raw materials, effectively avoids the situation that petroleum resources are increasingly scarce and petroleum-based monomers are unsustainable, and the developed liquid crystal copolyester has excellent heat resistance, effectively improves the use temperature of the filter material, and can meet the purification demand of high-temperature flue gas in industrial production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and particularly relates to a liquid crystal polyester-amide-imide based on bio-based diamine and preparation and application thereof. BACKGROUND

[0002] With the increasing environmental requirements in industrial production, the development of dust removal technology is increasingly valued. The bag-type dust collector is an effective dust removal tool for purifying industrial waste gas, and the filter material is the core of the bag-type dust collector. The polyester filter material is a kind of widely used smoke filter material, but the traditional polyester smoke filter material can only be used at a low temperature and cannot meet the purification requirements of high-temperature smoke discharged in industrial production. Therefore, it is particularly important to modify the polymer of polyester and improve the use temperature of polyester filter material for its application in industrial production.

[0003] CN202220889342.3 discloses a low-elongation polyester filter material without base cloth, in which the warp yarn and weft yarn of the fiber layer are connected with resistance metal wires in the middle, which can improve the strength and anti-deformation ability of the polyester filter material. However, this kind of filter material still cannot meet the use requirements in high-temperature environment. Therefore, it is of great significance to develop high-temperature-resistant smoke filter material to realize the purification of high-temperature industrial waste gas in actual industrial production. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a liquid crystal polyester-amide-imide based on bio-based diamine and preparation and application thereof, and particularly to provide an environmentally friendly bio-based high-temperature-resistant liquid crystal polyester-amide-imide resin and its smoke filter material application, so as to meet the purification requirements of high-temperature smoke waste gas in industrial production.

[0005] The present application provides a polyester-amide-imide, characterized in that the polyester-amide-imide has the following structural formula:

[0006]

[0007] wherein R1 and R2 are selected from (CH2) m , m≥3; x+y+z=1, 0.1≤x≤0.3, 0.1≤y≤0.3, 0.4≤z≤0.8; n≥20.

[0008] Preferably, the polyester-amide-imide has the following structural formula:

[0009]

[0010]

[0011] wherein x+y+z=1, 0.2≤x≤0.3, 0.2≤y≤0.3, 0.4≤z≤0.6; n≥20.

[0012] The application provides a polyester-amide-imide preparation method, comprising:

[0013] Vanillic acid, imide diacid, bio-based diamine, acetic anhydride and catalyst are mixed to perform acetylation reaction, then ester exchange reaction is performed, and then post-polycondensation reaction is performed to obtain polyester-amide-imide.

[0014] Preferably, the molar ratio of the vanillic acid, bio-based diamine and imide diacid monomer is 40-60:20-30:20-30.

[0015] Preferably, the acetic anhydride feeding amount is 1.4-2.0 times of the amount of substance of the amino group in the bio-based diamine and the hydroxyl group in the vanillic acid.

[0016] Preferably, the catalyst feeding amount is 0.1-1.0% of the total mass of the monomers (vanillic acid, bio-based diamine and imide diacid).

[0017] Preferably, the catalyst is one or more of potassium acetate, zinc acetate and sodium hypophosphite.

[0018] Preferably, the bio-based diamine comprises one or more of butanediamine, pentanediamine and decanediamine.

[0019] Preferably, the acetylation reaction comprises: reacting at 120-150 DEG C under a protective gas condition for 30-90 min.

[0020] Preferably, the ester exchange reaction comprises: warming to 250-280 DEG C at a warming rate of 0.8-1.2 DEG C / min to perform ester exchange reaction, and then vacuumizing the system to further react under a vacuum degree of 1-3 mbar until the polymer climbs the rod to end the reaction.

[0021] Further, after the ester exchange reaction is completed, the obtained product is ground into powder in a protective gas atmosphere, and post-polycondensation reaction is performed at a temperature of 220-260 DEG C and a vacuum degree of 1-3 mbar for 24-48 h to obtain liquid crystal polyester-amide-imide product.

[0022] The protective gas is one of nitrogen and inert gas.

[0023] Preferably, the imide diacid has the structural formula:

[0024] Wherein, m is greater than or equal to 3.

[0025] Further, the imide diacid has the structural formula:

[0026]

[0027] One of them.

[0028] Preferably, the preparation of the imide diic acid includes: obtaining it through reaction using raw materials containing trimellitic anhydride and bio-based diamine; wherein the bio-based diamine monomer is one or more of butanediamine, pentanediamine, and decanediamine; the molar ratio of trimellitic anhydride to bio-based diamine monomer is 1 to 2:1; the reaction is carried out under reflux for 1 to 3 hours, wherein the reflux temperature is 120 to 160°C.

[0029] Further, the preparation of the imidic diacid includes: mixing trimellitic anhydride with a solvent, stirring and heating to 80-160°C, and after the trimellitic anhydride is completely dissolved in the solvent, adding bio-based diamine, refluxing and reacting for 1-3 hours, purifying, and drying to obtain the imidic diacid.

[0030] The solvent amount is 1-6 times the total mass of the monomers fed; the solvent is acetic acid; the purification includes: after the reaction is completed, the reactant solution is cooled to room temperature, the solvent is removed by vacuum filtration, and the filtered product is washed with ethanol solvent.

[0031] The present invention provides a polyester-amide-imide nonwoven fabric, which is prepared by melt-blowing based on the polyester-amide-imide resin in a temperature range of 300 to 320°C.

[0032] The present invention provides a smoke and dust filter material, which is composed of the polyester-amide-imide nonwoven fabric.

[0033] This invention provides an application of the polyester-amide-imide resin, the polyester-amide-imide nonwoven fabric, or the dust filter material in the field of waste gas purification, such as in the field of high-temperature waste gas purification.

[0034] This invention utilizes an environmentally friendly liquid crystal polyester-amide-imide resin to prepare liquid crystal polyester-amide-imide nonwoven fabric via meltblowing, resulting in a high-temperature resistant flue gas filter material. The flue gas filter material involved in this invention not only has an environmentally friendly raw material source but also possesses excellent thermal stability, effectively meeting the purification needs of high-temperature flue gas released in industrial production, and has a wide range of applications.

[0035] Beneficial effects

[0036] Compared to traditional polyester filter media, the liquid crystal polyester-amide-imide involved in this invention uses bio-based monomers as raw materials, which effectively avoids the current situation of increasingly scarce petroleum resources and unsustainable development of petroleum-based monomers. Moreover, the developed resin has excellent heat resistance, which effectively improves the operating temperature of this filter media and can meet the purification needs of high-temperature flue gas in industrial production. Attached Figure Description

[0037] Figure 1 Schematic diagram of dust filter material and microstructure of nonwoven fabric dust filter material;

[0038] Figure 2 Differential scanning calorimetry curve of polyester-amide-imide resin;

[0039] Figure 3 The thermogravimetric curves of polyester-amide-imide resin are shown. Detailed Implementation

[0040] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims. The sources and specifications of the raw materials and reagents used in the experiments are shown in Table 1:

[0041] Table 1 Experimental Materials and Reagents

[0042] Name Specification Factory Vanillic acid 99％ Shanghai Maikelin Biochemical Technology Co., Ltd. Terephthalic acid 99％ Hengyi Petrochemical Co., Ltd. Butanediamine 99.9％ Shanghai Maikelin Biochemical Technology Co., Ltd. Pentanediamine 99.9％ Ningxia Yipin Biological Technology Co., Ltd. Decanediamine 99.9％ Hubei Hongfuda Biological Technology Co., Ltd. Imide diacid 99％ Self-made Acetic anhydride 98.5％ Shanghai Titan Technology Co., Ltd. Potassium acetate 99％ Beijing Inokai Technology Co., Ltd.

[0043] Example 1

[0044] This embodiment prepares a bio-based liquid crystal polyester-amide-imide material using the following method:

[0045] Acetic acid (1309.2 g) and trimellitic anhydride (384.2 g) were added to a three-necked flask. The mixture was heated to 120 °C until the solution became clear, and butanediamine (88.2 g) was added. The mixture was then refluxed at 140 °C for 1 h. The reaction mixture was cooled to 25 °C, filtered to remove acetic acid, and washed with ethanol until no acidic odor remained. The mixture was then dried in an oven (80 °C, 24 h) to obtain an imide diacid monomer powder.

[0046] In a 500 mL three-necked flask, vanillic acid (0.6 mol, 100.89 g), butanediamine (0.2 mol, 17.63 g), imidized dicarboxylic acid (0.2 mol, 90.08 g), 94.53 mL of acetic anhydride, and 0.209 g of potassium acetate were added, respectively. The flask was equipped with a sealed stirrer and related mechanical stirring devices. A nitrogen inlet pipe and control valve were installed on one side of the flask to control the nitrogen flow rate according to the reaction progress. A condenser was installed on the other side to collect the volatile acetic acid. The entire reaction system was maintained at 120 °C under a nitrogen atmosphere for 90 min for acetylation. Subsequently, the temperature was increased to 280 °C at a reaction rate of 0.8 °C / min for transesterification. The reaction was then maintained at this temperature and a vacuum was drawn to 3 mbar. The reaction was stopped when the polymer began to climb the rod. After the reaction, the product was cooled in an inert gas atmosphere, ground into powder, and subjected to a post-condensation reaction at 260°C and a vacuum of 3 mbar for 24 h to obtain a polyester-amide-imide resin (structure shown in the figure below). The resin was melted at 320°C using a single-screw extruder, then spun through a meltblown die and cooled to obtain a nonwoven fabric. High-temperature resistant dust filter media prepared from this nonwoven fabric can be applied to dust filtration in special environments.

[0047]

[0048] Example 2

[0049] This embodiment prepares a bio-based liquid crystal polyester-amide-imide material using the following method: The imide diacid monomer is prepared using the same method as in Example 1. Then, vanillic acid (0.4 mol, 67.26 g), butanediamine (0.3 mol, 26.44 g), imide diacid (0.3 mol, 135.12 g), 94.53 mL of acetic anhydride, and 0.229 g of potassium acetate are added to a 500 mL three-necked flask. A sealed stirrer and related mechanical stirring device are installed in the middle of the flask. A nitrogen inlet pipe and control valve are installed on one side of the flask to control the nitrogen flow rate according to the reaction progress. A condenser is installed on the other side to collect the volatilized acetic acid. The entire reaction system is maintained at 150 °C under a nitrogen atmosphere for 30 min for acetylation. Subsequently, the temperature is increased to 250 °C at a reaction rate of 1.2 °C / min for transesterification. The temperature is then maintained and a vacuum is drawn to 1 mbar. The reaction is stopped when the polymer begins to climb the rod. After the reaction, the product was cooled in an inert gas atmosphere, ground into powder, and subjected to a post-condensation reaction at 220°C and a vacuum of 3 mbar for 48 hours to obtain a liquid crystal polyester-amide-imide product. The relevant resin was melted at 320°C using a single-screw extruder, then spun through a meltblown die and cooled to obtain a nonwoven fabric. High-temperature resistant dust filter media prepared from this nonwoven fabric can be applied to dust filtration in special environments.

[0050]

[0051] Comparative Example 1

[0052] This comparative example prepared petroleum-based liquid crystal polyester-amide-imide, which is used in comparison with Examples 1 and 2. The method is as follows: In a 500 mL three-necked flask, p-hydroxybenzoic acid (0.4 mol, 55.25 g), butanediamine (0.3 mol, 26.44 g), imide diacid (0.3 mol, 135.12 g), 94.53 mL of acetic anhydride, and 0.217 g of potassium acetate were added, respectively. A sealed stirrer and related mechanical stirring device were installed in the middle of the flask. A nitrogen inlet pipe and control valve were installed on one side of the flask to control the nitrogen flow rate according to the reaction progress. A condenser was installed on the other side to collect the volatile acetic acid. The entire reaction system was acetylated under a nitrogen atmosphere at 150 °C for 90 min. Subsequently, the temperature was increased to 250 °C at a reaction rate of 0.8 °C / min for transesterification. The temperature was then maintained and a vacuum was drawn to 3 mbar. The reaction was stopped when the polymer began to climb the rod. After the reaction was completed, the product was cooled to room temperature in an inert gas atmosphere. The resulting product was then pulverized and subjected to a post-condensation reaction at 220°C and a vacuum of 1 mbar for 48 hours. The relevant resin was melted at 320°C using a single-screw extruder, and then spun through a meltblown die. After cooling, a nonwoven fabric was obtained.

[0053]

[0054] Performance tests were conducted on Examples 1 and 2, and Comparative Example 1.

[0055] 1) Differential Scanning Calorimetry (DSC)

[0056] The test procedure was as follows: In a nitrogen atmosphere, the temperature was increased from 30°C to 380°C at a rate of 20°C / min. The liquid crystal phase transition temperature was T. K-N .

[0057] 2) Thermogravimetric analysis (TGA)

[0058] The test procedure was as follows: the temperature was increased from 30℃ to 600℃ at a rate of 10℃ / min. The temperature at which 5% weight loss occurred was taken as the thermal decomposition temperature (T). d,5％ ).

[0059] Examples 1-2 and Comparative Example 1 were subjected to DSC tests under a nitrogen atmosphere with a heating / cooling rate of 20℃ / min, as shown in Table 2: The petroleum-based polyester-amide-imide obtained in Comparative Example 1 melted at 308℃; the bio-based polyester-amide-imide obtained in Examples 1-2 had similar melting temperatures of 305℃ and 309℃, respectively, indicating that the bio-based polyester-amide-imide resin prepared from bio-based imide diacid monomers has a high polymer melting point, which can meet the requirements for use at high temperatures.

[0060] Examples 1-2 and Comparative Example 1 were all subjected to TGA testing at a heating rate of 10 °C / min, as shown in Table 2: TGA of the petroleum-based liquid crystal polyester-amide-imide obtained in Comparative Example 1. d,5％ The temperature reached 426℃; compared with Comparative Example 1, the thermal decomposition temperature (T) of the bio-based liquid crystal polyester-amide-imide obtained in Examples 1-2 was 426℃. d,5％ The excellent results indicate that bio-based polyester-amide-imide also has good thermal stability.

[0061] Table 2. Material properties of Examples 1-2 and Comparative Example 1

[0062]

[0063]

Claims

1. A polyester-amide-imide, characterized in that, The general formula of the polyester-amide-imide structure is: R1 and R2 are selected from (CH2). m , m≥3; x+y+z=1, 0.1≤x≤0.3, 0.1≤y≤0.3, 0.4≤z≤0.8; n≥20.

2. The polyester-amide-imide according to claim 1, characterized in that, The polyester-amide-imide structural formula includes: Where x+y+z=1, 0.2≤x≤0.3, 0.2≤y≤0.3, 0.4≤z≤0.6; n≥20.

3. A method for preparing the polyester-amide-imide according to claim 1, comprising: Vanillic acid, imide diacid, bio-based diamine, acetic anhydride and catalyst are mixed and subjected to acetylation, followed by transesterification and then post-condensation to obtain polyester-amide-imide.

4. The preparation method according to claim 3, characterized in that, The molar ratio of vanillic acid, bio-based diamine, and imide diacid is 40-60:20-30:20-30; the amount of acetic anhydride added is 1.4-2.0 times the amount of hydroxyl substances in the monomer; and the amount of catalyst added is 0.1-1.0% of the total mass of the monomer.

5. The preparation method according to claim 3, characterized in that, The catalyst is one or more of potassium acetate, zinc acetate, and sodium hypophosphite; The structure of the imide diacid is as follows: Where m ≥ 3. The bio-based diamine includes one or more of butanediamine, pentamethylenediamine, and decanediamine.

6. The preparation method according to claim 3, characterized in that, The acetylation reaction includes: reacting at 120-150℃ for 30-90 min under a protective gas condition; The transesterification reaction includes: under protective gas conditions, heating to 250-280℃ at a heating rate of 0.8-1.2℃ / min to carry out the transesterification reaction, then evacuating the system to 1-3mbar, and stopping the reaction when the polymer begins to climb. The post-condensation reaction includes: a vacuum post-condensation reaction for 24 to 48 hours at a temperature of 220-260℃ and a vacuum degree of 1-3 mbar.

7. The preparation method according to claim 6, characterized in that, The protective gas is either nitrogen or an inert gas.

8. A polyester-amide-imide nonwoven fabric, characterized in that, The polyester-amide-imide nonwoven fabric is prepared by melt-blowing based on the polyester-amide-imide resin of claim 1 at a temperature range of 300-320°C.

9. A smoke and dust filter material, characterized in that, The dust filter material is mainly composed of the polyester-amide-imide nonwoven fabric described in claim 8.

10. The application of the polyester-amide-imide resin of claim 1, the polyester-amide-imide nonwoven fabric of claim 8, or the dust filter material of claim 9 in the field of waste gas purification.

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