Liquid crystal polyester-amide-imide based on bio-based diamine as well as preparation and application of liquid crystal polyester-amide-imide

Abstract

The invention relates to liquid crystal polyester-amide-imide based on bio-based diamine and preparation and application thereof.The liquid crystal polyester-amide-imide uses bio-based monomers as raw materials, effectively avoids the current development situations that petroleum resources are in shortage day by day and petroleum-based monomers are not sustainable, and has the advantages of being simple in preparation process, low in cost and high in practicability. And the developed liquid crystal copolyester has excellent heat resistance, effectively improves the use temperature of the filter material, and can meet the purification requirements of high-temperature flue gas in industrial production.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and particularly relates to a liquid crystal polyester-amide-imide based on bio-based diamines and the preparation and application thereof. Background Art

[0002] As people's requirements for environmental protection in industrial production increase, the development of dust removal technology has received increasing attention. Bag dust collectors are an effective dust removal tool for purifying industrial waste gas, and filter media is the core of bag dust collectors. Polyester filter media is a type of smoke filter media with a wide range of applications, but traditional polyester smoke filter media can only be used at lower temperatures and cannot meet the purification needs of high-temperature smoke emitted in industrial production. Therefore, it is particularly important to modify the polyester polymer and increase the use temperature of polyester filter media for its application in industrial production.

[0003] CN202220889342.3 discloses a low-elongation polyester filter material without a base cloth. The warp yarn and the weft yarn of the filter material fiber layer are connected with an impedance metal wire, which can improve the strength and deformation resistance of the polyester filter material. However, this filter material still cannot meet the use requirements in high-temperature environments. Therefore, in actual industrial production, it is of great significance to develop high-temperature resistant smoke filter materials to achieve high-temperature industrial waste gas purification. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a liquid crystal polyester-amide-imide based on bio-based diamines and its preparation and application, in particular to provide an environmentally friendly bio-based high temperature resistant liquid crystal polyester-amide-imide resin and its smoke filter material application to meet the needs of high temperature smoke exhaust gas purification in industrial production.

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

[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 present invention provides a method for preparing polyester-amide-imide, comprising:

[0013] Vanillic acid, imide diacid, bio-based diamine, acetic anhydride and a catalyst are mixed, acetylated, transesterified and then post-polycondensed 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 amount of acetic anhydride added is 1.4-2.0 times the amount of the amino group in the bio-based diamine and the hydroxyl group in the vanillic acid.

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

[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, pentamethylenediamine and decanediamine.

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

[0020] Preferably, the transesterification reaction comprises: heating the temperature to 250-280°C at a heating rate of 0.8-1.2°C / min to carry out the transesterification reaction, and then evacuating the system to further react under a vacuum degree of 1-3 mbar until the polymer climbs the pole and then the reaction is terminated;

[0021] Furthermore, after the transesterification reaction is completed, the product is cooled in a protective gas atmosphere, ground into powder, and subjected to post-polycondensation reaction at a temperature of 220-260° C. and a vacuum degree of 1-3 mbar for 24 to 48 hours to obtain a liquid crystal polyester-amide-imide product.

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

[0023] Preferably, the structural formula of the imide diacid is:

[0024] Where m≥3.

[0025] Furthermore, the structural formula of the imide diacid is:

[0026]

[0027] One of them.

[0028] Preferably, the preparation of the imide diacid includes: obtaining it by reaction with raw materials containing trimellitic anhydride and bio-based diamine; wherein the bio-based diamine monomer is one or more of butanediamine, pentamethylenediamine, and decanediamine; the molar ratio of trimellitic anhydride to the bio-based diamine monomer is 1 to 2:1; the reaction is condensed and refluxed for 1 to 3 hours, wherein the condensation and reflux temperature is 120 to 160°C.

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

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

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

[0032] The invention provides a smoke filter material, which is composed of the polyester-amide-imide based non-woven fabric.

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

[0034] In the present invention, based on the environmentally friendly liquid crystal polyester-amide-imide resin, a liquid crystal polyester-amide-imide non-woven fabric is prepared by melt-blowing method, and a high temperature resistant smoke filter material is obtained. The smoke filter material involved in the present invention not only has an environmentally friendly raw material source, but also has excellent thermal stability, can effectively cope with the purification needs of high temperature smoke exhaust gas released in industrial production, and has a wide range of application scenarios.

[0035] Beneficial Effects

[0036] Compared with traditional polyester filter materials, the liquid crystal polyester-amide-imide involved in the present invention uses bio-based monomers as raw materials, which effectively avoids the increasing shortage of petroleum resources and the unsustainable development of petroleum-based monomers. The developed resin has excellent heat resistance, which effectively increases the use temperature of this filter material and can meet the purification needs of high-temperature flue gas in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of smoke filter material and microscopic morphology of smoke filter material nonwoven fabric;

[0038] Figure 2 is the differential scanning calorimetry curve of polyester-amide-imide resin;

[0039] Figure 3 This is the thermal gravimetric loss curve of polyester-amide-imide resin. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application. The sources and specifications of the raw materials and reagents used in the experiment are shown in Table 1:

[0041] Table 1 Experimental materials and reagents

[0042] name Specification factory Vanillic acid 99％ Shanghai MacLean Biochemical Technology Co., Ltd. Terephthalic acid 99％ Hengyi Petrochemical Co., Ltd. Butanediamine 99.9％ Shanghai MacLean Biochemical Technology Co., Ltd. Pentamethylenediamine 99.9％ Ningxia Yipin Biotechnology Co., Ltd. Decanediamine 99.9％ Hubei Hongfuda Biotechnology Co., Ltd. Imidioic acid 99％ self made Acetic anhydride 98.5％ Shanghai Titan Technology Potassium acetate 99％ Beijing Inotech Technology Co., Ltd.

[0043] Example 1

[0044] In this embodiment, a bio-based liquid crystal polyester-amide-imide material is prepared by the following method:

[0045] Add acetic acid (1309.2g) and trimellitic anhydride (384.2g) into a three-necked flask. Heat at 120℃ until the solution is clear, add diaminobutane (88.2g), condense and reflux at 140℃ for 1h. Cool the reactants to 25℃, filter to remove acetic acid, wash with ethanol until there is no sour smell, and dry in an oven (80℃, 24h) to obtain imide diacid monomer powder.

[0046] In a 500mL three-necked flask, vanillic acid (0.6mol, 100.89g), diaminobutane (0.2mol, 17.63g), imidodiacid (0.2mol, 90.08g), 94.53mL acetic anhydride and 0.209g potassium acetate were added. The middle of the flask was equipped with a closed stirring paddle and related mechanical stirring devices. One side of the flask was equipped with a nitrogen inlet pipe and a control valve to control the nitrogen flow rate according to the reaction process. The other side was equipped with a condenser to condense and collect the volatile acetic acid. The temperature was maintained at 120℃, and the entire reaction system was acetylated in a nitrogen atmosphere for 90min. Subsequently, the temperature was raised to 280℃ at a reaction rate of 0.8℃ / min to carry out the ester exchange reaction. Then, the temperature was kept and vacuum was pumped to 3mbar. The reaction was stopped after the polymer climbed the pole. After the reaction is completed, the mixture is cooled in an inert gas atmosphere, the obtained copolyester product is ground into powder, and a post-condensation reaction is carried out at a temperature of 260°C and a vacuum degree of 3 mbar for 24 hours to obtain a polyester-amide-imide resin (the structure is shown below). The relevant resin is melted at 320°C by a single screw extruder, and then spun through a melt-blown die head and cooled to obtain a non-woven fabric. The high-temperature resistant smoke filter material prepared based on the non-woven fabric can be used for smoke filtration in special environments.

[0047]

[0048] Example 2

[0049] This embodiment prepares bio-based liquid crystal polyester-amide-imide material, and the method is as follows: the preparation method of imide diacid monomer is the same as that of Example 1, and then vanillic acid (0.4mol, 67.26g), diamine (0.3mol, 26.44g), imide diacid (0.3mol, 135.12g), 94.53mL acetic anhydride and 0.229g potassium acetate are added to a 500mL three-necked flask. The middle of the flask is equipped with a closed stirring paddle and a related mechanical stirring device. One side of the flask is equipped with a nitrogen inlet pipe and a control valve to control the nitrogen flow rate according to the reaction process, and the other side is equipped with a condensing device to condense and collect the volatile acetic acid. Maintaining the temperature at 150°C, the entire reaction system is acetylated for 30min under a nitrogen atmosphere. Subsequently, the temperature is raised to 250°C at a reaction rate of 1.2°C / min to carry out an ester exchange reaction. Then keep warm and start evacuating to 1mbar, and stop the reaction after the polymer climbs the pole. After the reaction is completed, the mixture is cooled in an inert gas atmosphere, the obtained copolyester product is ground into powder, and a post-condensation reaction is carried out at a temperature of 220°C and a vacuum degree of 3 mbar for 48 hours to obtain a liquid crystal polyester-amide-imide product. The relevant resin is melted at 320°C by a single screw extruder, and then spun through a melt-blown die head and cooled to obtain a non-woven fabric. The high-temperature resistant smoke filter material prepared based on the non-woven fabric can be used for smoke filtration in special environments.

[0050]

[0051] Comparative Example 1

[0052] This comparative example prepares a petroleum-based liquid crystal polyester-amide-imide for comparison with Examples 1 to 2, and the method is as follows: p-hydroxybenzoic acid (0.4 mol, 55.25 g), diaminodiamine (0.3 mol, 26.44 g), imidodiacid (0.3 mol, 135.12 g), 94.53 mL of acetic anhydride and 0.217 g of potassium acetate are added to a 500 mL three-necked flask. The middle of the flask is equipped with a closed stirring paddle and a related mechanical stirring device, one side of the flask is equipped with a nitrogen inlet pipe and a control valve to control the nitrogen flow rate according to the reaction process, and the other side is equipped with a condensing device to condense and collect the volatile acetic acid. Maintaining the temperature at 150 ° C, the entire reaction system is acetylated in a nitrogen atmosphere for 90 minutes. Subsequently, the temperature is raised to 250 ° C at a reaction rate of 0.8 ° C / min to carry out an ester exchange reaction. Then keep warm and start vacuuming to 3 mbar, and stop the reaction after the polymer climbs the pole. After the reaction, the mixture was cooled to room temperature in an inert gas atmosphere, the obtained product was crushed, and then subjected to post-polycondensation reaction at 220°C and 1 mbar vacuum for 48 hours. The relevant resin was melted at 320°C by a single screw extruder, and then spun through a melt-blown die and cooled to obtain a non-woven fabric.

[0053]

[0054] The performance of Examples 1 to 2 and Comparative Example 1 was tested

[0055] 1) Differential Scanning Calorimetry (DSC)

[0056] The test procedure is: nitrogen atmosphere, heating from 30℃ to 380℃ at 20℃ / min, liquid crystal phase transition temperature is T K-N .

[0057] 2) Thermogravimetric analysis test (TGA)

[0058] The test procedure is: heating from 30°C to 600°C at a heating rate of 10°C / min. The temperature corresponding to 5% weight loss is taken as the thermal decomposition temperature (T d,5％ ).

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

[0060] Examples 1 to 2 and Comparative Example 1 were all subjected to TGA tests 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％ Reached 426 ℃; Examples 1 to 2 obtained bio-based liquid crystal polyester-amide-imide compared with the comparative example 1, the thermal decomposition temperature (T d,5％ ) is excellent, indicating that bio-based polyester-amide-imide also has good thermal stability.

[0061] Table 2 Physical properties of Examples 1 to 2 and Comparative Example 1

[0062]

[0063]

Claims

1. A polyester-amide-imide, characterized in that: The polyester-amide-imide general structure formula is: 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.

2. The polyester-amide-imide according to claim 1, characterized in that: The polyester-amide-imide structural formula comprises: Wherein 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 a polyester-amide-imide, comprising: Vanillic acid, imide diacid, bio-based diamine, acetic anhydride and a catalyst are mixed, acetylated, transesterified and then post-polycondensed to obtain polyester-amide-imide.

4. The preparation method according to claim 3, characterized in that: The molar ratio of the 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 the hydroxyl substance of the added monomer; and the amount of the catalyst added is 0.1-1.0% of the total weight 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: 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 comprises: reacting at 120-150° C. for 30-90 minutes under protective gas conditions; The transesterification reaction comprises: heating the temperature to 250-280° C. at a heating rate of 0.8-1.2° C. / min under protective gas conditions to carry out the transesterification reaction, then evacuating the system to 1-3 mbar, and reacting until the polymer climbs the pole and then ending the reaction; The post-polycondensation reaction comprises: performing a vacuum post-polycondensation reaction for 24 to 48 hours at a temperature of 220-260° C. and a vacuum degree of 1-3 mbar.

7. The preparation method according to claim 6, characterized in that: The protective gas is one of nitrogen and inert gas.

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

9. A smoke filter material, characterized in that: The smoke filter material is mainly composed of the polyester-amide-imide based non-woven fabric described in claim 8.

10. Use of the polyester-amide-imide resin according to claim 1, the polyester-amide-imide nonwoven fabric according to claim 8 or the smoke filter material according to claim 9 in the field of exhaust gas purification.

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