CN112250848B - Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof - Google Patents
Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof Download PDFInfo
- Publication number
- CN112250848B CN112250848B CN202011044919.2A CN202011044919A CN112250848B CN 112250848 B CN112250848 B CN 112250848B CN 202011044919 A CN202011044919 A CN 202011044919A CN 112250848 B CN112250848 B CN 112250848B
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- flame
- thermotropic
- monomer
- aromatic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
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
- C08G63/68—Polyesters containing atoms other than carbon, hydrogen and oxygen
- C08G63/685—Polyesters containing atoms other than carbon, hydrogen and oxygen containing nitrogen
-
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
The invention relates to the field of polyester materials, and discloses a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and a preparation method thereof, wherein the preparation method comprises the following steps: (1) performing acetylation reaction on a fully aromatic diphenol monomer, a fully aromatic diacid monomer, an AB type fully aromatic monomer containing a terminal carboxyl group A and a terminal hydroxyl group B, an active terminal group compound, polyester particles, acetic anhydride and a catalyst under the protection of inert gas at 120-150 ℃; (2) heating to 300-340 ℃ to perform ester exchange reaction; (3) further reacting at 300-320 ℃ under the condition of 1-3 mbar; (4) and cooling in an inert gas atmosphere, grinding the obtained product into powder, and performing post-polycondensation reaction at 200-260 ℃ under the condition of 1-3 mbar to obtain the target product. The thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material has the advantages of low melting point, anti-dripping property and no harmful gas generation during combustion.
Description
Technical Field
The invention relates to the field of polyester materials, in particular to a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and a preparation method thereof.
Background
The semi-aromatic polyester is used as a high polymer material with wide application, and has wide application in civil and industrial aspects due to the characteristics of high strength, high modulus and low water absorption. Polyester fiber, also known as terylene, occupies most of the share of chemical fiber industry. The class of polyesters that are marketed includes PET, PBT, PTT, and the like. As the polymer can be oxidized and degraded at high temperature, once the polymer is burnt, a fire is easily formed, and the life and property safety of people can be seriously influenced. Therefore, the flame retardant property of the polyester material is improved, and the flame retardant property has great significance.
The patent CN107938014A discloses a preparation method of a flame-retardant thermotropic polyarylate liquid crystal fiber, wherein a thermotropic liquid crystal polyarylate slice is obtained by introducing a phosphorus-containing aromatic unit into a main chain, the slice is spun into filaments by melt extrusion, and finally the flame-retardant thermotropic polyarylate liquid crystal fiber is prepared by post-treatment. The process flow is simple, the fiber has good flame retardant effect, but white smoke and molten drops can be generated during combustion due to the phosphorus flame retardant. Therefore, in order to reduce the dripping of the flame-retardant polyester fiber and the harm to human body, research on a novel phosphorus-free flame-retardant polyester material is urgently needed.
On the other hand, if the main chain of the liquid crystalline polyarylate is a rigid linear structure, it needs to be melted at a high temperature (300 ℃ or higher) to be molded, and the liquid crystalline polyarylate monomer is relatively expensive, which further increases the production cost.
In conclusion, the research on how to improve the anti-dripping performance of the polyester and reduce the production cost of the polyarylate liquid crystal material is expected to become a topic with great application value.
Disclosure of Invention
The invention provides a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and a preparation method thereof, aiming at solving the technical problems that phosphorus flame-retardant polyester has high melting point, generates molten drops during combustion and generates harmful gases in the prior art. The thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material has low melting point, anti-dripping property and no harmful gas generated during combustion.
The specific technical scheme of the invention is as follows:
in a first aspect, the present invention provides a thermotropic flame retardant anti-dripping aromatic liquid crystal copolyester material, which has a chemical structural formula of one of the following:
wherein n is 2-20, and m is 90-100; r is (CH) 2 )x，X＝2～4。
The rigid main chain mesogen element of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material is composed of AA, BB or AB type monomers containing ester bonds, amido bonds, imide bonds or ether bonds or a combination of the monomers, the rigid elementary monomers and polyester granules are copolymerized, end capping is carried out by active groups such as phenylacetylene or norbornene acetylene, and the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material is prepared by one-pot melt polycondensation reaction. Naphthalene monomers are introduced into the molecular chain of the obtained copolymer to destroy the linearity of the main chain, the molecular chain is in a semi-aromatic structure, and compared with a straight-chain wholly aromatic liquid crystal material, the melt processing temperature is lower. On the other hand, both ends of the molecular chain are blocked by active groups which can be thermally cured, such as phenylacetylene or norbornene acetylene, and the like, so that cycloaddition reaction can occur under a high-temperature environment (350-. Finally, the material does not contain phosphorus flame retardant, so no harmful gas is generated during combustion.
Preferably, the molecular weight of the liquid crystal copolyester material is between 1000 and 10000 g/mol.
In a second aspect, the invention provides a preparation method of a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material, which comprises the following steps:
(1) adding a fully aromatic diphenol monomer, a fully aromatic diacid monomer, an AB type fully aromatic monomer containing a terminal carboxyl group A and a terminal hydroxyl group B, polyester particles, an active end group compound, acetic anhydride and a catalyst into a reactor; and performing acetylation reaction under the protection of inert gas at the temperature of 120-150 ℃.
In the reaction of the stage, phenolic hydroxyl groups in diphenol monomers and AB type wholly aromatic monomers are acetylated to generate corresponding aromatic ester and generate partial acetic acid, so that the condition that the AB type monomers are sublimated at the temperature and condensed on a container wall to reduce raw materials participating in the reaction is avoided, and meanwhile, preparation is made for the next transesterification reaction.
(2) Heating to 300-340 ℃ to perform ester exchange reaction.
The degree of transesterification at about 300 ℃ is high, a large amount of acetic acid is generated by the transesterification, and small molecules generated by the reaction are difficult to discharge due to the gradual increase of the viscosity of the system, so that the increase of the polymerization degree is restricted, and therefore, the small molecules need to be discharged by vacuumizing to improve the molecular weight.
(3) Further reacting at 300-320 ℃ and 1-3 mbar vacuum degree.
Acetic acid micromolecules in the system are discharged under the vacuum condition, the viscosity of the system is further increased, and the ester exchange reaction is basically finished when no acetic acid is generated in the system.
(4) And after the reaction is finished, cooling in an inert gas atmosphere, grinding the obtained product into powder, and performing post-polycondensation reaction at the temperature of 200-260 ℃ and the vacuum degree of 1-3 mbar to further improve the molecular weight of the product, thereby finally obtaining the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material.
Preferably, in the step (1), the wholly aromatic diphenol monomer is one or more of 4, 4' -biphenol, hydroquinone and resorcinol.
Preferably, in the step (1), the wholly aromatic diacid monomer is one or more of 1, 4-terephthalic acid, 1, 7-naphthalenedicarboxylic acid and 2, 6-naphthalenedicarboxylic acid.
Preferably, in the step (1), the AB type wholly aromatic monomer containing both the terminal carboxyl group A and the terminal hydroxyl group B is one or more of 4-hydroxybenzoic acid, 4' -hydroxybiphenyl-4-carboxylic acid and 6-hydroxy-2-naphthoic acid.
Preferably, in step (1), the reactive end group compound is one or more of the following compounds:
wherein Y is amino or imino; z is hydroxyl, carboxyl, ester group or carbonyl.
Preferably, in the step (1), the catalyst is one or more of sodium acetate, potassium acetate, zinc acetate, antimony trioxide, tetrabutyl titanate and germanium dioxide.
Preferably, in step (1), the polyester particles are one or more of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT).
Preferably, in the step (1), the molar ratio of the fully aromatic diphenol monomer, the fully aromatic diacid monomer, the AB type fully aromatic monomer containing the terminal carboxyl A and the terminal hydroxyl B, the polyester particles and the active terminal group compound is 10-40: 80-20: 100-500: 2-8;
the molar weight of the acetic anhydride is 50-100% of the total amount of hydroxyl in the raw material, and the molar weight of the catalyst is 0.1-0.5% of the total amount of the raw material.
The AB type monomer is used as a common monomer of liquid crystal polymers, has low price and high reaction activity, and is used as a main component of the liquid crystal copolyester. The wholly aromatic diphenol and the wholly aromatic diacid are usually selected from a small part of nonlinear structural monomers to destroy the linear regularity of the liquid crystal copolyester, and reduce the melting point for processing. The amount of the active end group compound is calculated according to the molecular weight of the liquid crystal copolyester expected to be synthesized. The larger the proportion of the polyester particles in the liquid crystal copolyester is, the lower the melting point of the liquid crystal copolyester is, but the lower the thermal stability of the liquid crystal copolyester is, so that the dosage of the polyester particles needs to be strictly controlled within a certain range. To ensure that all of the hydroxyl groups in the monomer are acetylated, acetic anhydride is typically present in an excess of 50-100% over the hydroxyl groups. The amount of the catalyst is required to ensure that the reaction is catalyzed and the influence on the reaction is minimized, and is usually 0.1-0.5 percent of the total mole amount of the raw materials.
Preferably, in the step (1), the acetylation reaction time is 30-60 min.
Preferably, in the step (2), the ester exchange reaction time is 1-3 h; the heating rate is 0.5-1.5 ℃/min;
preferably, in the step (3), the reaction time is 10-30 min.
Preferably, in the step (4), the reaction mixture is cooled to room temperature in an inert gas atmosphere, and the post-polycondensation reaction time is 18-36 h.
Compared with the prior art, the invention has the following technical effects:
(1) the high molecular chain of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material is in a semi-aromatic structure, and has lower melting processing temperature compared with a straight-chain wholly aromatic liquid crystal material. In addition, a cross-linked network structure formed after the thermosetting reaction of the active end groups has excellent flame-retardant and anti-dripping performances, and can effectively reduce life and property losses caused by fire, so that the flame-retardant and anti-dripping flame-retardant polyester resin has wide application prospects in the fields of civil textiles and high-temperature protective materials.
(2) The molecular weight of the aromatic liquid crystal copolyester is controllable in the polymerization process, and materials with different molecular weights can be obtained according to requirements.
(3) The aromatic liquid crystal copolyester prepared by the invention does not contain any solvent, no small molecule is generated in the curing process, thermotropic liquid crystal polyarylate plates and fibers can be prepared by hot pressing or melt spinning, and the solvent is not required to be removed in the process, so that the preparation process is simpler, more efficient and more environment-friendly;
(4) the aromatic liquid crystal copolyester prepared by the invention does not contain phosphorus flame retardant, so that harmful gas is not generated during combustion.
Drawings
FIG. 1 is a hot stage polarization microscope photograph of the product obtained in example 1 of the present invention;
FIG. 2 is a DSC chart of comparative example 1 and examples 1 to 3 of the present invention.
Detailed Description
The present invention will be further described with reference to the following examples.
General examples
A thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material has a chemical structural formula of one of the following:
wherein n is 2-20, and m is 90-100; r is (CH) 2 ) X and X are 2-4. Preferably, the molecular weight of the liquid crystal copolyester material is between 1000 and 10000 g/mol.
A preparation method of a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps:
(1) adding a fully aromatic diphenol monomer, a fully aromatic diacid monomer, an AB type fully aromatic monomer containing a terminal carboxyl group A and a terminal hydroxyl group B, polyester particles, an active end group compound, a proper amount of acetic anhydride (the molar weight is 50-100% of the total molar weight of hydroxyl groups in the raw materials) and a catalyst (the molar weight is 0.1-0.5% of the total molar weight of the raw materials) into a reactor according to the molar ratio of 10-40: 80-20: 100-500: 2-8; and performing acetylation reaction for 30-60 min under the protection of inert gas and at the temperature of 120-150 ℃.
(2) Heating to 300-340 ℃ at a heating rate of 0.5-1.5 ℃/min, and carrying out ester exchange reaction for 1-3 h.
(3) Further reacting for 10-30 min under the conditions that the temperature is 300-320 ℃ and the vacuum degree is 1-3 mbar.
(4) After the reaction is finished, cooling to room temperature in an inert gas atmosphere, grinding the obtained product into powder, and performing post-polycondensation reaction for 18-36 h under the conditions that the temperature is 200-260 ℃ and the vacuum degree is 1-3 mbar, so as to obtain the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material.
The wholly aromatic diphenol monomer is one or more of 4, 4' -biphenol, hydroquinone and resorcinol.
The wholly aromatic diacid monomer is one or more of 1, 4-terephthalic acid, 1, 7-naphthalene dicarboxylic acid and 2, 6-naphthalene dicarboxylic acid.
The AB type wholly aromatic monomer containing both the terminal carboxyl group A and the terminal hydroxyl group B is one or more of 4-hydroxybenzoic acid, 4' -hydroxybiphenyl-4-carboxylic acid and 6-hydroxy-2-naphthoic acid.
The active end group compound is one or more of the following compounds:
wherein Y is amino or imino; z is hydroxyl, carboxyl, ester group or carbonyl.
The catalyst is one or more of sodium acetate, potassium acetate, zinc acetate, antimony trioxide, tetrabutyl titanate and germanium dioxide.
The polyester particles are one or more of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT).
Example 1
The preparation of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps: 4, 4' -dihydroxybiphenyl, terephthalic acid, 2, 6-naphthalenedicarboxylic acid, p-hydroxybenzoic acid, PET particles, N- (3-carboxyphenyl) -4-phenylethynylphthalimide, N- (3-hydroxyphenyl) -4-phenylethynylphthalimide, as well as acetic anhydride and potassium acetate were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 100: 80: 20: 800: 1000: 80: 1800: 4. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 120 ℃ for 30min in a fluid sand bath with a moderate nitrogen flow and then raised to 340 ℃ at a heating rate of 1.5 ℃/min for 1h of transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 1mbar and a temperature of 300 ℃ for 10 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 36h at 260 ℃ and under the vacuum degree of 3mbar to obtain the target product.
Example 2
The preparation of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps: hydroquinone, terephthalic acid, 1, 7-naphthalenedicarboxylic acid, 6-hydroxy-2-naphthoic acid, PBT particles, 3-ethynylaniline, 2- (3-ethynylphenyl) -1, 3-dioxoisoindole-5-carboxylic acid, and acetic anhydride and zinc acetate were added in a 250 ml three-neck round-bottom flask in a molar ratio of 200: 160: 40: 600: 5000: 20: 1200: 36. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 150 ℃ for 60min in a fluid sand bath with a moderate nitrogen flow and then raised to 320 ℃ at a heating rate of 1.5 ℃/min for 3h transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 3mbar and a temperature of 320 ℃ for 30 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. Performing solid state polycondensation reaction for 18h at 200 ℃ and under the vacuum degree of 1mbar to obtain the target product.
Example 3
The preparation of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps: resorcinol, terephthalic acid, 1, 7-naphthalenedicarboxylic acid, 4' -hydroxybiphenyl-4-carboxylic acid, PTT particles, acetic acid, 4- (1, 3-dioxo-1, 3, 3a, 4, 7, 7 a-hexahydro-2H-4, 7-methylisoindol-2-yl) acetic acid phenyl ester, 4- (1, 3-dioxo-1, 3, 3a, 4, 7, 7 a-hexahydro-2H-4, 7-methylisoindol-2-yl) benzoic acid, acetic anhydride and sodium acetate were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 400: 240: 160: 200: 2000: 60: 1020: 12. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 140 ℃ for 40min in a fluid sand bath with a moderate nitrogen flow and then raised to 300 ℃ at a heating rate of 0.5 ℃/min for 2h transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 2mbar and a temperature of 310 ℃ for 20 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 18h at 230 ℃ and under the vacuum degree of 2mbar to obtain the target product.
Example 4
The preparation of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps: 4, 4' -dihydroxybiphenyl, terephthalic acid, 2, 6-naphthalenedicarboxylic acid, p-hydroxybenzoic acid, PET particles, N- (3-carboxyphenyl) -4-phenylethynylphthalimide, N- (3-hydroxyphenyl) -4-phenylethynylphthalimide, acetic anhydride and titanium oxide were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 300: 200: 100: 400: 4000: 70: 1190: 12. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 140 ℃ for 40min in a fluid sand bath with a moderate nitrogen flow and then raised to 310 ℃ at a heating rate of 1 ℃/min for 3h transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 3mbar and a temperature of 310 ℃ for 20 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 24 hours at the temperature of 240 ℃ and under the vacuum degree of 2mbar to obtain the target product.
Example 5
The preparation of the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material comprises the following steps: hydroquinone, terephthalic acid, 1, 7-naphthalenedicarboxylic acid, 6-hydroxy-2-naphthoic acid, PBT particles, 3-ethynylaniline, 2- (3-ethynylphenyl) -1, 3-dioxoisoindole-5-carboxylic acid, acetic anhydride and germanium dioxide were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 100: 80: 20: 800: 1000: 80: 1530: 7. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 140 ℃ for 40min in a fluid sand bath with a moderate nitrogen flow and then raised to 300 ℃ at a heating rate of 0.5 ℃/min for 2h transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 2mbar and a temperature of 310 ℃ for 20 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 24 hours at 230 ℃ under the vacuum degree of 2mbar to obtain the target product.
Comparative example 1
Preparation of pure thermotropic flame-retardant aromatic liquid crystal polymer: 4, 4' -dihydroxybiphenyl, terephthalic acid, 2, 6-naphthalenedicarboxylic acid, p-hydroxybenzoic acid, N- (3-carboxyphenyl) -4-phenylethynylphthalimide, N- (3-hydroxyphenyl) -4-phenylethynylphthalimide, as well as acetic anhydride and potassium acetate were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 100: 80: 20: 800: 80: 1800: 3. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 140 ℃ for 40min in a fluid sand bath with a moderate nitrogen flow and then raised to 300 ℃ at a heating rate of 0.5 ℃/min for 2h transesterification. At this time, the reaction system was slowly evacuated to a vacuum of 2mbar and a temperature of 310 ℃ for 20 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 24 hours at 230 ℃ and under the vacuum degree of 2mbar to obtain the target product.
Comparative example 2
Preparation of pure thermotropic phosphorus-containing flame-retardant aromatic liquid crystal polymer: 4, 4 '-dihydroxybiphenyl, 4' - (phenoxyphosphine) -dibenzoic acid, 2, 6-naphthalenedicarboxylic acid, p-hydroxybenzoic acid, acetic anhydride and potassium acetate were added in a 250 ml three-necked round-bottomed flask in a molar ratio of 100: 80: 20: 800: 1700: 3. The flask was fitted with a sealed glass paddle stirrer, a nitrogen inlet and an insulated distillation head. The reaction mixture was acetylated at 140 ℃ for 40min in a fluid sand bath with a moderate nitrogen flow and then raised to 300 ℃ at a heating rate of 0.5 ℃/min for 2h transesterification. At this point, the reaction system was slowly evacuated to a vacuum of 2mbar and a temperature of 310 ℃ for 20 min. The opaque melt was cooled to room temperature and the product was removed from the flask and ground to a fine powder. And carrying out solid state polycondensation reaction for 24 hours at 230 ℃ and under the vacuum degree of 2mbar to obtain the target product.
Performance testing
The liquid crystallinity of example 1 was measured using a hot stage polarizing microscope (see fig. 1); the thermal properties of the products were measured by Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA), and the flame retardancy was determined by measuring the vertical burning of the products while the intrinsic viscosity, thermal properties and flame retardancy and the intrinsic viscosity test results are shown in tables 1 and 2, respectively, and the DSC curves of comparative example 1 and examples 1-3 are shown in fig. 2.
The apparent banding texture can be seen in FIG. 1, indicating that the product of example 1 has a nematic liquid crystal texture and belongs to a liquid crystal copolyester. As can be seen from FIG. 2 and Table 1, the melting point of the pure thermotropic liquid crystalline polymer of comparative example 1 is 267 ℃ while the melting points of the copolymers of examples 1 to 5 are higher than those of comparative example 1 and PET (T) m The temperature is 250-260 ℃, so that the molding production cost of the copolyester material can be reduced to a certain extent; meanwhile, the thermal decomposition temperature T of the liquid crystal copolyester d5％ All at above 370 ℃, and has higher thermal stability.
TABLE 1
As shown in Table 2, the vertical burning grade of the liquid crystal copolyester obtained in the comparative example 2 reaches V-0, but accompanied by molten drops and white smoke, while the flame retardant grades of the liquid crystal copolyesters obtained in the examples 1 to 5 reach V-0, and the liquid crystal copolyester does not have molten drops and white smoke during vertical burning, which shows that the liquid crystal copolyester obtained by the invention has good flame retardance and anti-molten drop performance under the condition of no phosphorus-containing flame retardant.
TABLE 2
The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.
Claims (8)
1. A preparation method of a thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material is characterized by comprising the following steps:
(1) adding a fully aromatic diphenol monomer, a fully aromatic diacid monomer, an AB type fully aromatic monomer containing a terminal carboxyl group A and a terminal hydroxyl group B, polyester particles, an active end group compound, acetic anhydride and a catalyst into a reactor; performing acetylation reaction under the protection of inert gas at the temperature of 120-150 ℃;
the wholly aromatic diphenol monomer is one or more of 4, 4' -biphenol, hydroquinone and resorcinol; the wholly aromatic diacid monomer is one or more of 1, 4-terephthalic acid, 1, 7-naphthalene dicarboxylic acid and 2, 6-naphthalene dicarboxylic acid; the AB type wholly aromatic monomer containing both the terminal carboxyl group A and the terminal hydroxyl group B is one or more of 4-hydroxybenzoic acid, 4' -hydroxybiphenyl-4-carboxylic acid and 6-hydroxy-2-naphthoic acid; the active end group compound is one or more of the following compounds:
wherein Y is amino or imino; z is hydroxyl, carboxyl, ester group or carbonyl;
the molar ratio of the fully aromatic diphenol monomer, the fully aromatic diacid monomer, the AB type fully aromatic monomer containing terminal carboxyl A and terminal hydroxyl B, the polyester particles and the active end group compound is 10-40: 10-40: 80-20: 100-500: 2-8;
(2) heating to 300-340 ℃, and carrying out ester exchange reaction;
(3) further reacting at the temperature of 300-320 ℃ and the vacuum degree of 1-3 mbar;
(4) and after the reaction is finished, cooling in an inert gas atmosphere, grinding the obtained product into powder, and performing post-polycondensation reaction at the temperature of 200-260 ℃ and the vacuum degree of 1-3 mbar to obtain the thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material.
2. The method of claim 1, wherein: in the step (1), the catalyst is one or more of sodium acetate, potassium acetate, zinc acetate, antimony trioxide, tetrabutyl titanate and germanium dioxide.
3. The method of claim 1, wherein: in the step (1), the polyester particles are one or more of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT).
4. The method of claim 1, wherein: in the step (1), the molar weight of the acetic anhydride is 50-100% of the total molar weight of the hydroxyl in the raw material, and the molar weight of the catalyst is 0.1-0.5% of the total molar weight of the raw material.
5. The method of claim 1, wherein: in the step (1), the acetylation reaction time is 30-60 min.
6. The method of claim 1, wherein: in the step (2), the ester exchange reaction time is 1-3 h; the heating rate is 0.5-1.5 ℃/min.
7. The method of claim 1, wherein: in the step (3), the reaction time is 10-30 min.
8. The method of claim 1, wherein: in the step (4), cooling to room temperature in an inert gas atmosphere, wherein the post-polycondensation reaction time is 18-36 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011044919.2A CN112250848B (en) | 2020-09-28 | 2020-09-28 | Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011044919.2A CN112250848B (en) | 2020-09-28 | 2020-09-28 | Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112250848A CN112250848A (en) | 2021-01-22 |
| CN112250848B true CN112250848B (en) | 2022-08-12 |
Family
ID=74233414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011044919.2A Active CN112250848B (en) | 2020-09-28 | 2020-09-28 | Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112250848B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112646141A (en) * | 2020-12-17 | 2021-04-13 | 上海思涛新材料科技有限公司 | Flame-retardant aromatic liquid crystal copolyester and preparation method thereof |
| CN113501941B (en) * | 2021-07-23 | 2022-08-16 | 宁夏清研高分子新材料有限公司 | Thermotropic liquid crystal polyester material and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455792A (en) * | 2000-09-13 | 2003-11-12 | 美国政府美国国家宇航管理局管理者代表 | Liquid crystalline thermosets from ester, ester-imide and ester-amide oligomers |
| CN103570927A (en) * | 2012-07-06 | 2014-02-12 | 金发科技股份有限公司 | Thermotropic liquid crystal polyester and preparation method thereof |
| CN106810676A (en) * | 2017-01-12 | 2017-06-09 | 苏州大学 | A kind of aromatic polyester and preparation method thereof |
| CN106810695A (en) * | 2017-01-12 | 2017-06-09 | 苏州大学 | A kind of aromatic polyesterimides and preparation method thereof |
| CN107793585A (en) * | 2017-10-30 | 2018-03-13 | 苏州大学 | A kind of liquid crystal flame-retardant foam material and preparation method thereof |
| CN110498760A (en) * | 2019-08-28 | 2019-11-26 | 东华大学 | A kind of aromatic thermosetting liquid crystal fiber and preparation method thereof |
-
2020
- 2020-09-28 CN CN202011044919.2A patent/CN112250848B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455792A (en) * | 2000-09-13 | 2003-11-12 | 美国政府美国国家宇航管理局管理者代表 | Liquid crystalline thermosets from ester, ester-imide and ester-amide oligomers |
| CN103570927A (en) * | 2012-07-06 | 2014-02-12 | 金发科技股份有限公司 | Thermotropic liquid crystal polyester and preparation method thereof |
| CN106810676A (en) * | 2017-01-12 | 2017-06-09 | 苏州大学 | A kind of aromatic polyester and preparation method thereof |
| CN106810695A (en) * | 2017-01-12 | 2017-06-09 | 苏州大学 | A kind of aromatic polyesterimides and preparation method thereof |
| CN107793585A (en) * | 2017-10-30 | 2018-03-13 | 苏州大学 | A kind of liquid crystal flame-retardant foam material and preparation method thereof |
| CN110498760A (en) * | 2019-08-28 | 2019-11-26 | 东华大学 | A kind of aromatic thermosetting liquid crystal fiber and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112250848A (en) | 2021-01-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112250848B (en) | Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester material and preparation method thereof | |
| KR101834703B1 (en) | Method of preparing aromatic liquid crystalline polyester resin and aromatic liquid crystalline polyester resin compound including the aromatic liquid crystalline polyester resin prepared by the method | |
| EP0220041B1 (en) | Copolyester | |
| KR20170056207A (en) | Method for preparing wholly aromatic polyester resin having improved flowability and wholly aromatic polyester resin prepared by the method | |
| CN112646153A (en) | Flame-retardant anti-dripping aromatic liquid crystal copolyester and preparation method thereof | |
| CN112144140B (en) | Preparation method of thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester fiber | |
| CN112646141A (en) | Flame-retardant aromatic liquid crystal copolyester and preparation method thereof | |
| CN112574402A (en) | Thermotropic anti-droplet aromatic liquid crystal copolyester and preparation method thereof | |
| CN112608459B (en) | Thermotropic aromatic liquid crystal copolyester and preparation method thereof | |
| CN112608461B (en) | Thermotropic flame-retardant anti-dripping aromatic liquid crystal copolyester and preparation method thereof | |
| KR101831878B1 (en) | Polyester fiber using binder Having Advanced Adhesive Strength | |
| JPS6383127A (en) | Production of copolyester | |
| JP2012122023A (en) | Liquid crystalline polyester | |
| JPH0319861B2 (en) | ||
| JPS63210127A (en) | Aromatic copolyester | |
| JPH0813878B2 (en) | Thermotropic liquid crystalline copolyester | |
| JPH03126718A (en) | Aromatic polyester | |
| JPS63146927A (en) | Aromatic copolyesteramide | |
| JPS63277233A (en) | Aromatic copolyester | |
| JPH0488015A (en) | Flame retardant polyester resin | |
| JPS63122730A (en) | Thermotropic liquid crystalline copolyester | |
| JPH024822A (en) | Polyester of cyclohexanedicarboxylic acid | |
| JPH0211624A (en) | Aromatic copolyester | |
| JPH0649192A (en) | Thermotropic copolyester | |
| JPH0369933B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 311200 29 Chenghu Road, Yaqian Town, Xiaoshan District, Hangzhou City, Zhejiang Province Applicant after: Zhejiang Hengyi Petrochemical Research Institute Co.,Ltd. Applicant after: Donghua University Address before: 311200 Room 501, 3 Blocks, Pearl Plaza, South Bank of Xiaoshan Economic and Technological Development Zone, Xiaoshan District, Hangzhou City, Zhejiang Province Applicant before: ZHEJIANG HENGLAN TECHNOLOGY Co.,Ltd. Applicant before: Donghua University |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |