CN112812282A - Liquid crystal polyester and preparation method and application thereof - Google Patents
Liquid crystal polyester and preparation method and application thereof Download PDFInfo
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- CN112812282A CN112812282A CN202011574911.7A CN202011574911A CN112812282A CN 112812282 A CN112812282 A CN 112812282A CN 202011574911 A CN202011574911 A CN 202011574911A CN 112812282 A CN112812282 A CN 112812282A
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- 229920000728 polyester Polymers 0.000 title claims abstract description 36
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 23
- 238000002360 preparation method Methods 0.000 title claims description 5
- 238000002844 melting Methods 0.000 claims abstract description 31
- 230000008018 melting Effects 0.000 claims abstract description 31
- 125000001424 substituent group Chemical group 0.000 claims abstract description 26
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims abstract description 24
- FJKROLUGYXJWQN-UHFFFAOYSA-N 4-hydroxybenzoic acid Chemical compound OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229940090248 4-hydroxybenzoic acid Drugs 0.000 claims abstract description 13
- KAUQJMHLAFIZDU-UHFFFAOYSA-N 6-Hydroxy-2-naphthoic acid Chemical compound C1=C(O)C=CC2=CC(C(=O)O)=CC=C21 KAUQJMHLAFIZDU-UHFFFAOYSA-N 0.000 claims abstract description 13
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 9
- 229960004337 hydroquinone Drugs 0.000 claims abstract description 6
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 claims description 9
- 238000006116 polymerization reaction Methods 0.000 claims description 9
- 239000007790 solid phase Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 6
- 238000005917 acylation reaction Methods 0.000 claims description 6
- 230000035484 reaction time Effects 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 238000006068 polycondensation reaction Methods 0.000 claims description 3
- 125000004178 (C1-C4) alkyl group Chemical group 0.000 claims description 2
- 125000006527 (C1-C5) alkyl group Chemical group 0.000 claims description 2
- 125000004169 (C1-C6) alkyl group Chemical group 0.000 claims description 2
- 125000003229 2-methylhexyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 claims description 2
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 claims description 2
- 125000004491 isohexyl group Chemical group C(CCC(C)C)* 0.000 claims description 2
- -1 isooctyl group Chemical group 0.000 claims description 2
- 125000001972 isopentyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])C([H])([H])* 0.000 claims description 2
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 claims description 2
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 claims description 2
- 229920005989 resin Polymers 0.000 abstract description 8
- 239000011347 resin Substances 0.000 abstract description 8
- 239000000178 monomer Substances 0.000 abstract description 5
- 125000003118 aryl group Chemical group 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract 1
- 229920000106 Liquid crystal polymer Polymers 0.000 description 10
- 239000004977 Liquid-crystal polymers (LCPs) Substances 0.000 description 10
- 238000012360 testing method Methods 0.000 description 8
- 229920001169 thermoplastic Polymers 0.000 description 7
- 239000004416 thermosoftening plastic Substances 0.000 description 7
- 230000004927 fusion Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000004974 Thermotropic liquid crystal Substances 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 238000002425 crystallisation Methods 0.000 description 3
- 230000008025 crystallization Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/60—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
- C08G63/605—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds the hydroxy and carboxylic groups being bound to aromatic rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
- C09K19/38—Polymers
- C09K19/3804—Polymers with mesogenic groups in the main chain
- C09K19/3809—Polyesters; Polyester derivatives, e.g. polyamides
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
The invention discloses a liquid crystal polyester, which consists of the following repeating units: (I) 49.8 to 89.8mol% of 4-hydroxybenzoic acid, (II) 10 to 50mol% of 2-hydroxy-6-naphthoic acid, (III) 0.01 to 5mol% of 3-substituent-4-hydroxybenzoic acid, (IV) 0.01 to 5mol% of 3-substituent-1, 4-phthalic acid, and (V) 0.01 to 5mol% of 3-substituent-1, 4-benzenediol, wherein the substituents of (III), (IV), (V) and (V) are hydrogen atoms and C1-C14 alkyl groups, but the substituents of (III), (IV) and (V) are not hydrogen atoms at the same time. By introducing monomer flexible alkyl to replace aromatic rings, the stacking among molecular chains is inhibited to form a regular structure through the steric hindrance effect of the aromatic rings, so that the crystallinity of the LCP resin is reduced, but the dielectric constant/dielectric loss performance is kept low. The liquid crystal polyester has low crystallinity, and the melting enthalpy measured by DSC is only 0.1-0.7J/g under the same condition; meanwhile, the liquid crystal polyester also has good dielectric property, the dielectric constant is 3.0-4.0, and the dielectric loss tangent value is 0.001-0.002.
Description
Technical Field
The invention relates to the technical field of high polymer materials, in particular to liquid crystal polyester and a preparation method and application thereof.
Background
The thermoplastic liquid crystal polymer film has extremely low dielectric constant/dielectric loss performance and excellent flexibility, can meet the requirements of high-frequency-band signal transmission of a 5G communication technology on low signal loss of an antenna material and the design requirements of personal terminal equipment on a multilayer three-dimensional complex structure of the antenna material, is gradually popularized in the antenna material of the 5G communication personal terminal equipment, and can replace the traditional polyimide material to become the mainstream of the market in the future.
However, since a general thermoplastic liquid crystal polymer resin has a linear polymer chain structure with very strong rigidity, it is very easy to form a regular structure by stacking and cause crystallization, and local crystallization is easily caused by temperature reduction during a film forming process to cause deterioration of uniformity of film appearance, thickness, mechanical properties and dielectric properties, and it is difficult to apply the resin to a 5G communication antenna material. The prior art mainly introduces a flexible alkyl monomer unit chain segment on a main chain of a thermoplastic liquid crystal polymer, and although the crystallinity of the thermoplastic liquid crystal polymer resin can be reduced so as to improve the uniformity of a thin film, the thermotropic liquid crystal performance of the material is reduced so as to increase the processing difficulty, and the low dielectric constant/dielectric loss performance can be damaged.
Disclosure of Invention
The invention aims to provide a liquid crystal polyester which has the advantage of low crystallization performance and maintains low dielectric constant/dielectric loss performance.
A liquid crystalline polyester consisting of the following repeating units: (I) 49.8 to 89.8mol% of 4-hydroxybenzoic acid, (II) 10 to 50mol% of 2-hydroxy-6-naphthoic acid, (III) 0.01 to 5mol% of 3-substituent-4-hydroxybenzoic acid, (IV) 0.01 to 5mol% of 3-substituent-1, 4-phthalic acid, and (V) 0.01 to 5mol% of 3-substituent-1, 4-benzenediol, wherein the substituents of (III), (IV), (V) and (V) are hydrogen atoms and C1-C14 alkyl groups, but the substituents of (III), (IV) and (V) are not hydrogen atoms at the same time.
The substituent group is at least one of hydrogen atom, methyl, ethyl, isopropyl, tert-butyl, isopentyl, isohexyl, isoheptyl and isooctyl.
The substituent is preferably at least one of a hydrogen atom and a C1-C5 alkyl group as the unit (III) substituent, at least one of a hydrogen atom and a C1-C6 alkyl group as the unit (IV) substituent, and at least one of a hydrogen atom and a C1-C4 alkyl group as the (V) substituent, wherein at most one of the substituents in the units (III), (IV) and (V) is a hydrogen atom.
More preferably, the unit (III) substituent is at least one of a hydrogen atom and a C2-C3 alkyl group, the unit (IV) substituent is at least one of a hydrogen atom and a C2-C4 alkyl group, and the unit (V) substituent is at least one of a hydrogen atom and a methyl group, wherein at most one of the substituents in the units (III), (IV), (V) is a hydrogen atom.
The liquid crystal polyester with the stage structure has the following performance advantages:
the melting point of the liquid crystal polyester is 250-350 ℃, the melting point is measured by DSC, the temperature is raised to the highest temperature of the melting point plus 30 ℃ from room temperature under the condition of the temperature raising rate of 20 ℃/min, the temperature is kept for 3min and then is lowered to the room temperature at the rate of 20 ℃/min, a test sample is kept for 3min at the room temperature and then is raised to the highest temperature of the melting point plus 30 ℃ at the temperature raising rate of 20 ℃/min, a second melting curve of the liquid crystal polyester is obtained, and the melting peak of the curve is selected as the melting point.
The melt viscosity of the liquid crystal polyester is 25Pa.s-60Pa.s, the melt viscosity is tested by a capillary rheometer, the test temperature is 0-30 ℃ higher than the melting point, and the shear rate is 1000S-1Measured using a die having an inner diameter of 1mm and a length of 40 mm.
The liquid crystal polyester has melting enthalpy of 0.1-0.7J/g measured by DSC. And (3) measuring by adopting DSC, heating to the highest temperature of the melting point plus 30 ℃ from room temperature at the heating rate of 20 ℃/min, standing at the temperature for 3min, then cooling to the room temperature at the speed of 20 ℃/min, standing the test sample at the room temperature for 3min, then heating to the highest temperature of the melting point plus 30 ℃ at the heating rate of 20 ℃/min, obtaining a second melting curve of the liquid crystal polyester, and selecting the melting peak of the curve to calculate the melting enthalpy.
The preparation method of the liquid crystal polyester comprises the following steps:
step a, under the condition of nitrogen pressurization, 4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 3-substituent-4-hydroxybenzoic acid, 3-substituent-1, 4-phthalic acid and 3-substituent-1, 4-benzenediol are used as raw materials to carry out acylation reaction under the action of an acylating agent, wherein the pressure is kept between 0.1MPa and 0.2MPa, the reaction temperature is between 100 and 180 ℃, and the reaction time is between 30 minutes and 20 hours;
b, after the acylation reaction is finished, reducing the pressure in the reaction kettle to normal pressure, heating to 200-400 ℃ at the speed of 0.1-150 ℃/min, discharging acetic acid and unreacted acetic anhydride molecules from the rectifying column, reducing the pressure in the reaction kettle to 1-20 kPa when the receiving amount of the acetic acid reaches more than 90% of a theoretical value, keeping the reduced pressure condition, raising the temperature of a reaction system program to the highest reaction temperature, and carrying out melt polycondensation to obtain a prepolymer;
and c, cooling, solidifying and granulating the prepolymer, and carrying out solid-phase polymerization in a solid-phase polymerization container to obtain liquid crystal polyester particles, wherein the vacuum degree is 0.1 Pa-50 KPa, the solid-phase polymerization temperature is 160-340 ℃, and the reaction time is 0.5-40 hours.
The liquid crystal polyester is applied to preparing films.
The invention has the following beneficial effects
According to the invention, the flexible alkyl substituent is introduced to the rigid aromatic ring unit in the liquid crystal polyester molecular chain segment, so that the symmetry of the thermoplastic liquid crystal polymer molecular chain is damaged, the difficulty of stacking the thermoplastic liquid crystal polymer to form a regular structure can be increased, the crystallinity (the melting enthalpy is less than or equal to 0.7J/g) of the thermoplastic liquid crystal polymer is obviously reduced, and the uniformity of a liquid crystal polyester film product is improved; meanwhile, the rigid structure of the molecular chain can be kept to keep the thermotropic liquid crystal performance, so that the thermotropic liquid crystal is easy to process and form, and the low dielectric constant/dielectric loss performance is prevented from being damaged.
Detailed Description
The present invention will be further illustrated by the following specific examples and comparative examples, which are preferred embodiments of the present invention, but the present invention is not limited to the following examples, and is not particularly limited to the types of raw materials of the components used in the following specific examples.
The raw materials used in the present invention are commercially available.
Examples and comparative examples a method of preparing liquid crystalline polyesters:
step a, under the condition of nitrogen pressurization, 4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 3-substituent-4-hydroxybenzoic acid, 3-substituent-1, 4-phthalic acid and 3-substituent-1, 4-benzenediol are used as raw materials (the comparative example can be other types of monomers), and acylation reaction is carried out under the action of an acylating agent, wherein the pressure is kept between 0.01MPa and 0.1MPa, the reaction temperature is between 100 ℃ and 150 ℃, and the reaction time is between 30 minutes and 2 hours; b, after the acylation reaction is finished, reducing the pressure in the reaction kettle to normal pressure, heating to 300-400 ℃ at the speed of 0.1-150 ℃/min, discharging acetic acid and unreacted acetic anhydride molecules from the rectifying column, reducing the pressure in the reaction kettle to 1-20 kPa when the receiving amount of the acetic acid reaches more than 90% of a theoretical value, keeping the reduced pressure condition, raising the temperature of a reaction system program to the highest reaction temperature, and carrying out melt polycondensation to obtain a prepolymer; and c, cooling, solidifying and granulating the prepolymer, and carrying out solid-phase polymerization in a solid-phase polymerization container to obtain liquid crystal polyester particles, wherein the vacuum degree is 0.1 Pa-50 KPa, the solid-phase polymerization temperature is 160-340 ℃, and the reaction time is 0.5-40 hours.
The performance test method comprises the following steps:
(1) melting point: and the melting point is measured by DSC, the temperature is raised to the highest temperature of the melting point plus 30 ℃ under the condition of the temperature raising rate of 20 ℃/min from the room temperature, the temperature is lowered to the room temperature at the rate of 20 ℃/min after staying for 3min, the temperature is raised to the highest temperature of the melting point plus 30 ℃ again at the temperature raising rate of 20 ℃/min after the test sample stays for 3min at the room temperature, the second melting curve of the liquid crystal polyester is obtained, and the melting peak value of the curve is selected as the melting point.
(2) Melt viscosity: testing with capillary rheometer at 0-30 deg.C above melting point and with shear rate of 1000S-1Measured using a die having an inner diameter of 1mm and a length of 40 mm.
(3) Enthalpy of fusion: and (3) measuring by adopting DSC, heating to the highest temperature of the melting point plus 30 ℃ from room temperature at the heating rate of 20 ℃/min, standing at the temperature for 3min, then cooling to the room temperature at the speed of 20 ℃/min, standing the test sample at the room temperature for 3min, then heating to the highest temperature of the melting point plus 30 ℃ at the heating rate of 20 ℃/min, obtaining a second melting curve of the liquid crystal polyester, and selecting the melting peak of the curve to calculate the melting enthalpy.
(4) Dielectric constant/dielectric loss tangent: the measurement is carried out by adopting a vector network analyzer at normal temperature, the test sample is a resin sheet with the thickness of 1mm, and the measurement frequency is 2.5 GHz.
Table 1: EXAMPLES monomer composition (mol/%) of liquid crystal polyester and the results of various property tests
Continuing with Table 1:
from examples 2/4-13, it can be seen that the substituents of the monomers (III), (IV), (V) in the present invention have a great influence on the enthalpy of fusion, wherein the most preferred monomer-structured LCP resin has an enthalpy of fusion of 0.4-0.5J/g, the most preferred monomer-structured LCP resin has an enthalpy of fusion of 0.5-0.6J/g, and the less preferred monomer-structured LCP resin has an enthalpy of fusion of 0.6-0.7J/g.
Continuing with Table 1:
from comparative example 1, it is clear that the extremely strong rigidity of the unsubstituted repeating unit segment leads to an excessively high enthalpy of fusion.
Claims (9)
1. A liquid crystalline polyester characterized by being composed of the following repeating units: (I) 49.8 to 89.8mol% of 4-hydroxybenzoic acid, (II) 10 to 50mol% of 2-hydroxy-6-naphthoic acid, (III) 0.01 to 5mol% of 3-substituent-4-hydroxybenzoic acid, (IV) 0.01 to 5mol% of 3-substituent-1, 4-phthalic acid, and (V) 0.01 to 5mol% of 3-substituent-1, 4-benzenediol, wherein the substituents of (III), (IV), (V) and (V) are hydrogen atoms and C1-C14 alkyl groups, but the substituents of (III), (IV) and (V) are not hydrogen atoms at the same time.
2. The liquid-crystalline polyester of claim 1, wherein said substituent group is at least one of a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an isopentyl group, an isohexyl group, an isoheptyl group, and an isooctyl group.
3. The liquid-crystalline polyester according to claim 2, wherein the unit (III) substituent is at least one of a hydrogen atom and a C1-C5 alkyl group, the unit (IV) substituent is at least one of a hydrogen atom and a C1-C6 alkyl group, and the (V) substituent is at least one of a hydrogen atom and a C1-C4 alkyl group, wherein at most one of the substituents of the units (III), (IV), (V) is a hydrogen atom.
4. The liquid-crystalline polyester of claim 3, wherein the unit (III) substituent is at least one of a hydrogen atom and a C2-C3 alkyl group, the unit (IV) substituent is at least one of a hydrogen atom and a C2-C4 alkyl group, and the unit (V) substituent is at least one of a hydrogen atom and a methyl group, and wherein at most one of the substituents in the units (III), (IV), (V) is a hydrogen atom.
5. The liquid crystalline polyester of claim 1, wherein said liquid crystalline polyester has a melting point of 250 ℃ to 350 ℃.
6. The liquid crystalline polyester of claim 1, wherein the melt viscosity of the liquid crystalline polyester is 25pa.s to 60 pa.s.
7. The liquid crystalline polyester of claim 1, wherein the liquid crystalline polyester has a melting enthalpy of 0.1 to 0.7J/g as measured by DSC.
8. The process for producing a liquid-crystalline polyester according to any one of claims 1 to 7, which comprises the steps of:
step a, under the condition of nitrogen pressurization, 4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 3-substituent-4-hydroxybenzoic acid, 3-substituent-1, 4-phthalic acid and 3-substituent-1, 4-benzenediol are used as raw 3-substituent-4-hydroxybenzoic acid materials to carry out acylation reaction under the action of an acylating agent, wherein the pressure is kept between 0.1MPa and 0.2MPa, the reaction temperature is between 100 ℃ and 180 ℃, and the reaction time is between 30 minutes and 20 hours;
b, after the acylation reaction is finished, reducing the pressure in the reaction kettle to normal pressure, heating to 200-400 ℃ at the speed of 0.1-150 ℃/min, discharging acetic acid and unreacted acetic anhydride molecules from the rectifying column, reducing the pressure in the reaction kettle to 1-20 kPa when the receiving amount of the acetic acid reaches more than 90% of a theoretical value, keeping the reduced pressure condition, raising the temperature of a reaction system program to the highest reaction temperature, and carrying out melt polycondensation to obtain a prepolymer;
and c, cooling, solidifying and granulating the prepolymer, and carrying out solid-phase polymerization in a solid-phase polymerization container to obtain liquid crystal polyester particles, wherein the vacuum degree is 0.1 Pa-50 KPa, the solid-phase polymerization temperature is 160-340 ℃, and the reaction time is 0.5-40 hours.
9. Use of a liquid crystalline polyester according to any of claims 1 to 7 for the preparation of films.
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| CN202011574911.7A CN112812282A (en) | 2020-12-28 | 2020-12-28 | Liquid crystal polyester and preparation method and application thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114853992A (en) * | 2022-04-26 | 2022-08-05 | 四川大学 | Soluble low-dielectric-constant low-dielectric-loss flame-retardant full-aromatic copolyester and preparation method and application thereof |
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| US4161470A (en) * | 1977-10-20 | 1979-07-17 | Celanese Corporation | Polyester of 6-hydroxy-2-naphthoic acid and para-hydroxy benzoic acid capable of readily undergoing melt processing |
| CN110498913A (en) * | 2018-05-16 | 2019-11-26 | 臻鼎科技股份有限公司 | Modified polymeric liquid crystal copolymer, polymeric membrane and corresponding preparation method |
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2020
- 2020-12-28 CN CN202011574911.7A patent/CN112812282A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4161470A (en) * | 1977-10-20 | 1979-07-17 | Celanese Corporation | Polyester of 6-hydroxy-2-naphthoic acid and para-hydroxy benzoic acid capable of readily undergoing melt processing |
| CN110498913A (en) * | 2018-05-16 | 2019-11-26 | 臻鼎科技股份有限公司 | Modified polymeric liquid crystal copolymer, polymeric membrane and corresponding preparation method |
Non-Patent Citations (2)
| Title |
|---|
| PETER AVAKIAN ET AL: "Dynamic mechanical and dielectric relaxation in a series of main chain thermotropic liquid crystalline polyesters", 《POLYMER》 * |
| 李敏慧等: "取代基对芳脂族规则共聚酯液晶性能的影响", 《高分子材料科学与工程》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114853992A (en) * | 2022-04-26 | 2022-08-05 | 四川大学 | Soluble low-dielectric-constant low-dielectric-loss flame-retardant full-aromatic copolyester and preparation method and application thereof |
| CN114853992B (en) * | 2022-04-26 | 2024-04-26 | 四川大学 | Soluble low dielectric constant low dielectric loss flame-retardant wholly aromatic copolyester and preparation method and application thereof |
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