A method for producing a semi-aromatic polyamide-based composite material

Abstract

The application relates to a preparation method of a semi-aromatic polyamide-based composite material, belonging to the technical field of materials, and comprising the following steps: uniformly mixing PA6Z resin with reinforcing material after vacuum drying, and sequentially performing extrusion and pelletizing to obtain a composite material; the PA6Z resin is prepared by sequentially performing pre-polymerization and polycondensation reaction after mixing hexamethylenediamine, terephthalic acid and PA6Q salt, wherein the PA6Q salt is obtained by taking 6Q monomer and terephthalic acid as raw materials and performing reaction. The preparation method of the semi-aromatic polyamide-based composite material is simple, the mechanical property and heat resistance of the composite material are improved by designing the molecular structure of the PA6Z resin matrix, the process is controllable, and the product performance is stable.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of materials, and relates to a preparation method of a semi-aromatic polyamide-based composite material. BACKGROUND

[0002] Semi-aromatic polyamides (such as PA6T, PA9T, PA10T, etc.) are a kind of high-performance materials containing both aromatic rings and aliphatic chain segments in the main chain. Due to the synergistic effect of the rigid aromatic ring and the flexible aliphatic chain in the molecular chain, such materials have excellent heat resistance, mechanical strength and dimensional stability, and are widely used in electronic packaging, automobile lightweight, aerospace and other fields.

[0003] To further improve the performance, semi-aromatic polyamides are often used as the matrix of composite materials, and are reinforced by reinforcing materials (such as glass fibers, carbon fibers) or nanofillers (such as carbon nanotubes, graphene) to obtain higher strength, modulus and thermal stability and other properties.

[0004] However, at present, such composite materials still have the following problems:

[0005] ①Heat resistance needs to be improved - in high-temperature use environment, the material is prone to cause degradation of the resin matrix or damage to the reinforcing fiber, resulting in deterioration of mechanical properties, especially unmodified composite materials are prone to brittle after long-term heat exposure.

[0006] ②Low impact resistance - the rigid aromatic structure limits the plastic deformation ability of the molecular chain, making it difficult for the composite material to disperse energy through yield or micro-cracks under dynamic load (such as impact, vibration), resulting in low toughness fracture and poor impact resistance, making the composite material prone to brittle fracture under dynamic load.

[0007] Document 1 (Preparation and Performance Research of Short Glass Fiber Reinforced Nylon 12T Composite [D]. 2018.) discloses that the dried high-temperature resistant polyamide resin, flame retardant, glass fiber are melt blended through a twin-screw extruder to obtain a composite material with good flame retardance and physical and mechanical properties, but the impact resistance is not high.

[0008] Document 2 (Influence of Glass Fiber Content on PA10T / 1010 Composite Performance [J]. Engineering Plastics Application, 2018, 46(2):31) prepared a PA10T / GF / PTFE composite material by blending high-temperature resistant PA10T, solid lubricant polytetrafluoroethylene (PTFE) and reinforcing material glass fiber. The wear resistance of the composite material is improved, but the physical and mechanical properties of the matrix resin are reduced.

[0009] Document 3 (Preparation and Performance Research of Carbon Fiber Reinforced Nylon PA6T / 66 Copolymer Composite [J]. Plastics Industry, 2015, 43(4): 124.) uses a twin-screw extruder to prepare a carbon fiber (CF) and nylon copolymer (PA6T / 66) composite. The tensile strength and bending strength of the composite are improved to a certain extent, but the operation is complex, and the initial decomposition temperature, melting point, and impact resistance of the composite are not improved.

[0010] Therefore, it is of great significance to study a preparation method of a semi-aromatic polyamide-based composite to solve the above problems. SUMMARY

[0011] The purpose of the present application is to solve the problems in the prior art and provide a preparation method of a semi-aromatic polyamide-based composite.

[0012] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0013] A preparation method of a semi-aromatic polyamide-based composite, wherein PA6Z resin is uniformly mixed with reinforcing material after vacuum drying, and the composite is obtained by extrusion and granulation in sequence;

[0014] The chemical structure of PA6Z resin is as follows:

[0015] ;

[0016] Wherein, x>0, y>0, x+y=1, 40≤n≤500. If n is too small, the polymerization degree is too low, which will result in low relative viscosity and melt strength, and melt rupture or sagging is easy to occur during extrusion, blow molding and other processes, making it difficult to form and limiting the processing performance. If n is too large, the polymerization degree is too high, which makes it difficult for the high molecular chain to fully melt and homogenize during screw extrusion, possibly leading to uneven plasticization. The long high molecular chain leads to a sharp rise in melt viscosity and a decrease in flowability.

[0017] As a preferred technical scheme:

[0018] The preparation method of a semi-aromatic polyamide-based composite as described above, wherein the temperature for vacuum drying is 70-80℃, and the time is 24-72h.

[0019] The preparation method of a semi-aromatic polyamide-based composite as described above, wherein the reinforcing material is glass fiber or carbon fiber.

[0020] The preparation method of a semi-aromatic polyamide-based composite as described above, wherein the extrusion temperature is 290-310℃, and the extrusion rate is 30-50 r / min.

[0021] The method for preparing the semi-aromatic polyamide-based composite material as described above, the mass ratio of the PA6Z resin and the reinforcing material after vacuum drying is 1:0.05-1.

[0022] The method for preparing the semi-aromatic polyamide-based composite material as described above, the semi-aromatic polyamide-based composite material has a melt index of 20-38 g / 10 min, an initial degradation temperature of 470-490 DEG C, a heat distortion temperature of 290-340 DEG C, a tensile strength of 100-250 MPa, an elongation at break of 3.1%-3.9%, a bending strength of 140-280 MPa, a bending modulus of 5800-16800 MPa, and an impact strength of 6.9-8.9 KJ / m 2 .

[0023] The method for preparing the semi-aromatic polyamide-based composite material as described above, the PA6Z resin is prepared by: firstly, using 6Q monomers and terephthalic acid as raw materials to obtain PA6Q salt through reaction; and then mixing hexamethylene diamine, terephthalic acid and the PA6Q salt to sequentially perform pre-polymerization and polycondensation reactions to obtain the PA6Z resin.

[0024] The chemical structure of the 6Q monomer is .

[0025] The PA6Z resin prepared by the method has high mechanical properties, thermal stability, low water absorption and high dimensional stability, and specific analysis is as follows:

[0026] Tensile strength and elongation at break: since the rigidity of the 6Q chain segment is between that of the aliphatic chain segment and the aromatic benzene ring chain segment, by introducing the 6Q chain segment into the polymer, the ratio of the flexible alkyl chain in the polymer is reduced, so that the overall strength of the polymer is increased. In addition, compared with the chain segment containing benzene ring, the 6Q chain segment has stronger flexibility, so when the 6Q chain segment is introduced, the movement ability of the polymer molecular chain is stronger, and the relative displacement is more likely to occur, which affects the strength of the polymer. Therefore, the increase of the content of the 6Q chain segment promotes the increase of the tensile strength of the PA6Z. The elongation at break gradually increases because the benzene ring is prone to brittle fracture when stretched, resulting in a lower elongation at break of the PA6Z. After the introduction of the 6Q chain segment, the flexibility of the PA6Z molecular chain is enhanced, and thus the elongation at break is larger.

[0027] Bending strength and bending modulus: since the rigidity of the 6Q chain segment is higher than that of the hexamethylene diamine chain segment, after the introduction of the 6Q chain segment, the bending strength and the bending modulus of the PA6Z are both improved.

[0028] Impact strength: Impact strength is a parameter to characterize the toughness of polymer. The addition of 6Q segment increases the flexibility and movement ability of PA6Z molecular chain, and induces the generation of greater degree of craze shear band, thereby absorbing greater impact energy, so the impact strength gradually increases.

[0029] Water absorption: Due to the addition of 6Q segment, the movement ability of polymer molecular chain is enhanced, which promotes the crystallization of polymer and weakens the phenomenon of water absorption increase caused by the change of amide group density to a certain extent, so the water absorption of PA6Z decreases.

[0030] Solvent resistance: The interaction between PA6Z molecular chains is strong, and the arrangement tends to be dense, making it difficult for most organic solvent molecules to penetrate.

[0031] Thermal stability (melt index, initial degradation temperature, heat distortion temperature): Because the addition of 6Q segment increases the rigidity and density of polymer molecular chain, the interaction between polymer molecules is enhanced, and the movement ability of polymer molecular chain is also improved, which enhances the crystallization ability of polymer (rigid segment provides crystallization driving force, flexible segment provides local movement ability). The rigid segment (diacetylene structure) partially restricts the movement of the segment and has high bond energy. The thermal resistance of polymer is closely related to the tightness of molecular chain arrangement. The greater the tightness of molecular chain arrangement, the stronger the interaction between PA6Z molecular chains, thereby improving the thermal resistance of PA6Z.

[0032] Dimensional stability (thermal linear expansion): By introducing the relatively rigid 6Q segment into the molecular chain, the crystalline polymer has a more compact molecular structure, which improves the linearity of the polymer molecular skeleton. In the molecular axis direction, it is almost in the same plane and has a rod-like structure with rigidity and easy crystallization, resulting in little expansion in the direction of the molecular chain. Therefore, as the temperature rises, the thermal expansion perpendicular to the direction of the molecular chain will be inhibited. At the same time, the use of flexible monomers eliminates the thermal stress generated by rigid molecular chains and improves the flexibility of the material, so that the thermal linear expansion coefficient of PA6Z is reduced.

[0033] The preparation method of the semi-aromatic polyamide-based composite material as described above, and the specific preparation process of PA6Z resin is as follows:

[0034] (1) 1,5-hexadiyne, NaN3 and catalyst (cat.) are added to solvent I, and the product A is obtained by click chemistry reaction at 40-50℃ for 12-24h;

[0035] (2) Product A, CeCl3·7H2O and substance X are added to solvent II, and 6Q monomer is obtained by reacting at 60-80℃ for 24-48h; substance X is NaI, KI or RbI;

[0036] (3) 6Q monomer, terephthalic acid and distilled water are added into a normal-pressure reaction kettle, and after constant temperature reaction at 70-80°C for 2-5 hours, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 101-105°C, PA6Q salt powder is obtained;

[0037] (4) Hexamethylene diamine, terephthalic acid, benzoic acid (only as a molecular weight regulator), PA6Q salt and distilled water are added into a reaction kettle, inert gas is blown for 10-30 min, then the kettle is filled with the inert gas to 0.4-0.6 MPa, and heating is started under stirring, when the pressure in the kettle reaches 2.0-3.0 MPa, the inert gas is stopped, the excess water vapor is discharged, and the pressure in the kettle is kept stable, when the temperature in the kettle reaches 200-250°C, pressure maintaining reaction is carried out at this temperature for 1.5-5 h, and a prepolymer is obtained;

[0038] (5) The prepolymer is transferred into a polycondensation kettle, vacuum is drawn to -0.11 to -0.04 MPa, and reaction is carried out at 200-220°C for 4-8 h, the material is discharged from an extruder at 290-308°C, and granulation is carried out, and PA6Z resin is obtained.

[0039] The preparation method of a semi-aromatic polyamide-based composite material as described above, in step (1), the solvent I is methanol, ethanol or isopropanol, the catalyst is CuI or CuBr, and the molar ratio of 1,5-hexadiyne, NaN3, the solvent I and the catalyst is 1:2.5-4:10-50:0.1-0.5;

[0040] In step (2), the solvent II is acetonitrile, tetrahydrofuran, N,N-dimethylformamide or dimethyl sulfoxide, and the molar ratio of the product A, CeCl3·7H2O, the substance X and the solvent II is 1:3-3.6:18-24:200-1000;

[0041] In step (3), the molar ratio of the 6Q monomer, terephthalic acid and distilled water is 1:1.01-1.11:2-4;

[0042] In step (4), the inert gas is helium or argon, and the molar ratio of hexamethylene diamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1-1.1:0.05-0.15:2-5:10-30.

[0043] The preparation method of a semi-aromatic polyamide-based composite material as described above, in step (4), the chemical structure of the prepolymer is as follows:

[0044] ;

[0045] Wherein, x>0, y>0, x+y=1, and m≤40.

[0046] Invention principle:

[0047] The heat stability and mechanical properties of the composite material (i.e. semi-aromatic polyamide-based composite material) prepared by introducing a diacetylene structure into the PA6Z resin matrix instead of part of the pure alkyl chain are significantly changed.

[0048] First, the PA6Z resin matrix obtained by introducing a 6Q segment into the polymer has excellent heat resistance, making the prepared composite material excellent in heat stability.

[0049] Secondly, the mechanical properties of the composite material are also greatly improved, specifically:

[0050] Tensile strength: ① The rigid characteristics of the diacetylene structure in the PA6Z resin matrix enhance the intermolecular force of the backbone structure, and under the condition that the bonding force between the reinforcing material and the PA6Z matrix resin is good, the diacetylene structure will limit the deformation of the PA6Z matrix resin and bear more stress and load, thereby improving the tensile strength of the composite material; ② Due to the introduction of the diacetylene structure of the PA6Z resin matrix, the interfacial interaction with the reinforcing material is improved, the surface fracture energy of the composite material increases, and the resistance of the reinforcing material to be extracted from the PA6Z matrix resin is greater, so the tensile strength of the composite material increases.

[0051] Elongation at break: The performance of the composite material is mainly affected by the change of the resin matrix. In the PA6Z matrix composite system, the introduction of the diacetylene structure realizes the rigid-flexible balance effect at the molecular scale. While ensuring the interfacial bonding strength with the reinforcing material, its moderate segment flexibility is beneficial to the local orientation and slip of the molecular chain during stress transfer, and the rigid component in the structure maintains the integrity of the material as a whole by limiting plastic deformation. This synergistic effect at the molecular level makes the composite material exhibit better elongation at break performance than the wholly aromatic system at the macro level.

[0052] Bending performance: The introduction of the diacetylene structure increases the rigidity of the PA6Z resin matrix molecular chain and the interaction between the reinforcing material, making the bonding force between the PA6Z resin and the reinforcing material stronger, which can effectively resist deformation when the composite material bears bending stress, thereby improving the bending strength and modulus synchronously.

[0053] Bending strength and bending modulus: When the composite material is subjected to bending stress, the PA6Z matrix resin undergoes plastic deformation, and the diacetylene structure can realize partial stress loss. The diacetylene structure in the cross section of the composite material interacts with the reinforcing material, which increases the bending stress that the composite material can withstand. Since the diacetylene structure of the PA6Z resin matrix has strong bonding with the reinforcing material, the deformation of the composite material under fixed stress is also greatly reduced, so the bending modulus of the composite material is greatly improved.

[0054] Impact strength: The introduction of diyne structures into the resin matrix improves the impact strength of the composite material through two mechanisms: on the one hand, the molecular chain with its moderate rigidity-flexibility balance allows the PA6Z matrix resin to absorb energy through local deformation when the composite material is impacted; on the other hand, the diyne structures in the PA6Z resin act as stress concentration points, inducing the formation of silver streaks and shear bands. These microscopic deformation processes require a large amount of energy, thereby significantly improving the impact strength of the material.

[0055] Beneficial effects:

[0056] The invention discloses a method for preparing a semi-aromatic polyamide-based composite material. By designing the molecular structure of the PA6Z resin matrix, the mechanical properties and heat resistance of the composite material are improved. The process is controllable and the product performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 The synthetic route diagram of 6Q monomer;

[0058] Figure 2 The H NMR spectrum of 6Q monomer ( 1 H NMR) spectra;

[0059] Figure 3 The NMR spectrum of 6Q monomer ( 13 C NMR) spectra;

[0060] Figure 4 The synthetic route diagram of PA6Q salt;

[0061] Figure 5 The NMR spectrum of PA6Q salt is ( 1 H NMR) spectra;

[0062] Figure 6 This is the synthetic route diagram of PA6Z resin;

[0063] Figure 7 The NMR spectrum of PA6Z resin ( 1 H NMR) diagram. DETAILED DESCRIPTION

[0064] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, 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 fall equally within the scope limited by the appended claims of the application.

[0065] Performance test method:

[0066] Water absorption: according to GB / T 1034-2008 standard.

[0067] Solvent resistance: the test method is performed according to ASTM D471 (immersion test), and the test solvents are formic acid, toluene, methanol, trichloromethane, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide, and pyridine.

[0068] Linear expansion coefficient: tested according to GB / T 36800.2-2018 standard.

[0069] Melt index: according to GB / T 3682.1-2018 standard (the obtained results need to be converted in units).

[0070] Onset degradation temperature (TG): the thermal stability of the sample is analyzed by a thermal gravimetric analyzer, an appropriate amount of sample is placed in a crucible, and the test is performed in a nitrogen atmosphere, the test temperature is 30~700℃, and the heating rate is 20℃ / min.

[0071] Heat distortion temperature: according to GB / T 1634.1-2004 standard, the load is 0.45 MPa.

[0072] Mechanical properties: tensile properties and elongation at break are tested according to GB / T 1040-2006 standard; bending strength and bending modulus are tested according to GB / T 9341-2008 standard; and impact strength is tested according to GB / T 1843-2008 standard.

[0073] In the above test methods, if the sample is a semi-aromatic polyamide-based composite sample, the prepared semi-aromatic polyamide-based composite sample needs to be dried in a vacuum oven at 70℃ for 24h before testing, and then placed in a plastic injection molding equipment for injection molding.

[0074] Glass fiber specifications: 3mm long; diameter 10μm, manufacturer: Shandong Taishan Glass Fiber Co., Ltd.;

[0075] Carbon fiber specifications: T700-12K, manufacturer: Japan Toray TORAY Co., Ltd.

[0076] Example 1

[0077] A preparation method of a semi-aromatic polyamide material, the specific steps are as follows:

[0078] (1) Preparation of raw materials:

[0079] 1,5-hexadiyne (CAS 628-16-0); NaN3(CAS 26628-22-8); catalyst CuI; solvent I methanol; CeCl3.7H2O (CAS 18618-55-8); substance X NaI; solvent II acetonitrile; terephthalic acid; distilled water; hexamethylenediamine; benzoic acid;

[0080] (2) 1,5-hexadiyne, NaN3and catalyst are added into solvent I, and product A is obtained by click chemistry reaction at 40°C for 24h; wherein the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:2.5:10:0.1;

[0081] (3) product A, CeCl3.7H2O and substance X are added into solvent II, and 6Q monomer is obtained by reaction at 60°C for 48h; wherein the molar ratio of product A, CeCl3.7H2O, substance X and solvent II is 1:3:18:200;

[0082] The chemical structure of the prepared 6Q monomer is .

[0083] (4) as shown in Figures 4-5 , 6Q monomer, terephthalic acid and distilled water are added into a normal-pressure reaction kettle, and after reaction at 70°C for 5h, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 101°C, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.01:2;

[0084] (5) as shown in Figures 6-7 , hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, helium is purged for 10min, then the kettle is filled with helium to 0.6MPa, and heating is started under stirring, when the pressure in the kettle reaches 2MPa, the helium filling is stopped, excess water vapor is discharged, and the pressure in the kettle is maintained stable, when the temperature in the kettle reaches 200°C, the pressure is maintained at this temperature for 5h, and a prepolymer is obtained; wherein the molar ratio of hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1:0.15:2:10;

[0085] The chemical structure of the prepared prepolymer is as follows:

[0086] ;

[0087] (6) the prepolymer is transferred into a polycondensation kettle, vacuumized to-0.11MPa, and reacted at 200°C for 8h, and then discharged from an extruder at 290°C, cut into particles, and PA6Z resin, i.e. a semi-aromatic polyamide material, is obtained.

[0088] The chemical structure of the prepared semi-aromatic polyamide material is as follows:

[0089] ;

[0090] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption of the semi-aromatic polyamide material is 0.2%, the linear expansion coefficient is 10 ppm / ℃, the melt index is 40 g / 10 min, the initial degradation temperature is 450℃, and the heat distortion temperature is 200℃; the tensile strength of the semi-aromatic polyamide material is 50 MPa, the elongation at break is 3.3%, the bending strength is 98 MPa, the bending modulus is 2400 MPa, and the impact strength is 5.8 KJ / m 2 .

[0091] Example 2

[0092] A method for preparing a semi-aromatic polyamide material, the specific steps are as follows:

[0093] (1) Preparation of raw materials:

[0094] 1,5-hexadiyne (CAS 628-16-0); NaN3 (CAS 26628-22-8); the catalyst is CuI; the solvent I is methanol; CeCl3·7H2O (CAS 18618-55-8); the substance X is NaI; the solvent II is acetonitrile; terephthalic acid; distilled water; hexamethylenediamine; benzoic acid;

[0095] (2) As shown in Figure 1 , 1,5-hexadiyne, NaN3 and the catalyst are added to the solvent I, and the product A is obtained by click chemistry reaction at 42℃ for 21h; wherein the molar ratio of 1,5-hexadiyne, NaN3, the solvent I and the catalyst is 1:2.8:20:0.2;

[0096] (3) The product A, CeCl3·7H2O and the substance X are added to the solvent II, and 6Q monomer is obtained by reacting at 64℃ for 44h; wherein the molar ratio of the product A, CeCl3·7H2O, the substance X and the solvent II is 1:3.1:19:400;

[0097] As shown in Figures 1-3 , the chemical structure of the prepared 6Q monomer is .

[0098] (4) 6Q monomer, terephthalic acid and distilled water are added into a normal pressure reaction kettle, and after constant temperature reaction at 72℃ for 4 hours, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 101℃, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.03:2.4;

[0099] (5) Hexamethylene diamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, helium is blown for 13 min, then the kettle is filled with helium to 0.55 MPa, and heating is started under stirring, when the pressure in the kettle reaches 2.2 MPa, the helium filling is stopped, the excess water vapor is discharged, and the pressure in the kettle is kept stable, when the temperature in the kettle reaches 210℃, the pressure is kept at this temperature for 4 h to obtain a prepolymer; wherein the molar ratio of hexamethylene diamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1.02:0.13:2.5:14;

[0100] The chemical structure of the prepared prepolymer is as follows:

[0101] ;

[0102] (6) The prepolymer is transferred into a polycondensation kettle, vacuumized to -0.09 MPa, and reacted at 204℃ for 7 h, and then the material is discharged from the extruder at 293℃ and cut into particles to obtain PA6Z resin, i.e. a semi-aromatic polyamide material.

[0103] The chemical structure of the prepared semi-aromatic polyamide material is as follows:

[0104] ;

[0105] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption rate of the semi-aromatic polyamide material is 0.22%, the linear expansion coefficient is 10.9 ppm / ℃, the melt index is 50 g / 10 min, the initial degradation temperature is 451℃, and the heat distortion temperature is 220℃; the tensile strength of the semi-aromatic polyamide material is 52 MPa, the elongation at break is 3.5%, the bending strength is 100 MPa, the bending modulus is 2600 MPa, and the impact strength is 6.1 KJ / m 2 .

[0106] Example 3

[0107] A preparation method of a semi-aromatic polyamide material, the specific steps are as follows:

[0108] (1) Preparation of raw materials:

[0109] 1,5-hexadiyne (CAS 628-16-0); NaN3(CAS 26628-22-8); catalyst CuI; solvent I ethanol; CeCl3.7H2O (CAS 18618-55-8); substance X KI; solvent II tetrahydrofuran; terephthalic acid; distilled water; hexamethylenediamine; benzoic acid;

[0110] (2) 1,5-hexadiyne, NaN3and catalyst are added into solvent I, and product A is obtained by click chemistry reaction at 44°C for 19h; wherein the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:3.2:30:0.3;

[0111] (3) product A, CeCl3.7H2O and substance X are added into solvent II, and 6Q monomer is obtained by reaction at 68°C for 38h; wherein the molar ratio of product A, CeCl3.7H2O, substance X and solvent II is 1:3.2:20:600;

[0112] The chemical structure of the prepared 6Q monomer is .

[0113] (4) 6Q monomer, terephthalic acid and distilled water are added into a normal-pressure reaction kettle, and after constant temperature reaction at 74°C for 3h, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 102°C, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.05:3;

[0114] (5) hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, helium is purged for 17min, then the kettle is filled with helium to 0.5MPa, and heating is started under stirring, when the pressure in the kettle reaches 2.4MPa, helium filling is stopped, excess water vapor is discharged, and the pressure in the kettle is maintained stable, when the temperature in the kettle reaches 220°C, pressure maintaining reaction is carried out at this temperature for 3h, and a prepolymer is obtained; wherein the molar ratio of hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1.04:0.11:3:20;

[0115] The chemical structure of the prepared prepolymer is as follows:

[0116] ;

[0117] (6) the prepolymer is transferred into a polycondensation kettle, vacuum is drawn to-0.07MPa, and reaction is carried out at 208°C for 6h, and after discharge from an extruder at 296°C, the product is cut into particles, and PA6Z resin, i.e. a semi-aromatic polyamide material, is obtained.

[0118] The chemical structure of the prepared semi-aromatic polyamide material is:

[0119] ;

[0120] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption of the semi-aromatic polyamide material is 0.24%, the linear expansion coefficient is 11.7 ppm / ℃, the melt index is 59 g / 10 min, the initial degradation temperature is 453℃, and the heat distortion temperature is 238℃; the tensile strength of the semi-aromatic polyamide material is 54 MPa, the elongation at break is 3.7%, the bending strength is 102 MPa, the bending modulus is 2800 MPa, and the impact strength is 6.4 KJ / m 2 .

[0121] Example 4

[0122] A method for preparing a semi-aromatic polyamide material, the specific steps are as follows:

[0123] (1) Preparation of raw materials:

[0124] 1,5-hexadiyne (CAS 628-16-0); NaN3 (CAS 26628-22-8); the catalyst is CuBr; the solvent I is ethanol; CeCl3·7H2O (CAS 18618-55-8); the substance X is KI; the solvent II is N,N-dimethylformamide; terephthalic acid; distilled water; hexamethylenediamine; benzoic acid;

[0125] (2) 1,5-hexadiyne, NaN3 and catalyst are added to solvent I, and the product A is obtained by click chemistry reaction at 46℃ for 17h; wherein the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:3.5:35:0.4;

[0126] (3) Product A, CeCl3·7H2O and substance X are added to solvent II, and 6Q monomer is obtained by reacting at 72℃ for 36h; wherein the molar ratio of product A, CeCl3·7H2O, substance X and solvent II is 1:3.3:21:700;

[0127] The chemical structure of the prepared 6Q monomer is .

[0128] (4) 6Q monomer, terephthalic acid and distilled water are added into a normal pressure reaction kettle, and after constant temperature reaction at 76℃ for 2.5 hours, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 103℃, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.07:3.3;

[0129] (5) Hexanediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, argon is blown for 20 minutes, then argon is filled in the kettle to 0.45 MPa, and heating is started under stirring, when the pressure in the kettle reaches 2.6 MPa, the helium filling is stopped, the excess water vapor is discharged, and the pressure in the kettle is maintained stable, when the temperature in the kettle reaches 230℃, the pressure is maintained at this temperature for 2.5 hours to obtain a prepolymer; wherein the molar ratio of hexanediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1.06:0.09:3.5:23;

[0130] The chemical structure of the prepared prepolymer is as follows:

[0131] ;

[0132] (6) The prepolymer is transferred into a polycondensation kettle, vacuumized to-0.06 MPa, and reacted at 212℃ for 5 hours, and then the material is discharged from an extruder at 300℃, and granulated to obtain PA6Z resin, i.e. a semi-aromatic polyamide material.

[0133] The chemical structure of the prepared semi-aromatic polyamide material is as follows:

[0134] ;

[0135] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption rate of the semi-aromatic polyamide material is 0.25%, the linear expansion coefficient is 12.5 ppm / ℃, the melt index is 67 g / 10 min, the initial degradation temperature is 455℃, and the heat distortion temperature is 250℃; the tensile strength of the semi-aromatic polyamide material is 56 MPa, the elongation at break is 3.9%, the bending strength is 103 MPa, the bending modulus is 3000 MPa, and the impact strength is 6.8 KJ / m 2 .

[0136] Example 5

[0137] A preparation method of a semi-aromatic polyamide material, the specific steps are as follows:

[0138] (1) Preparation of raw materials:

[0139] 1,5-hexadiyne (CAS 628-16-0); NaN3(CAS 26628-22-8); catalyst is CuBr; solvent I is isopropanol; CeCl3·7H2O (CAS 18618-55-8); substance X is RbI; solvent II is N,N-dimethylformamide; terephthalic acid; distilled water; hexanediamine; benzoic acid;

[0140] (2) 1,5-hexadiyne, NaN3and catalyst are added into solvent I, and a product A is obtained by click chemistry reaction at 48°C for 15h; wherein the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:3.7:44:0.45;

[0141] (3) product A, CeCl3·7H2O and substance X are added into solvent II, and 6Q monomer is obtained by reaction at 76°C for 39h; wherein the molar ratio of product A, CeCl3·7H2O, substance X and solvent II is 1:3.5:23:900;

[0142] The chemical structure of the prepared 6Q monomer is .

[0143] (4) 6Q monomer, terephthalic acid and distilled water are added into a normal-pressure reaction kettle, and after constant-temperature reaction at 78°C for 2h, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 104°C, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.09:3.7;

[0144] (5) hexanediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, argon is blown for 25min, then the kettle is filled with argon to 0.43MPa, and heating is started under stirring, when the pressure in the kettle reaches 2.8MPa, the argon filling is stopped, excess water vapor is discharged, and the pressure in the kettle is maintained stable, when the temperature in the kettle reaches 240°C, pressure maintaining reaction is carried out at this temperature for 2h, and a prepolymer is obtained; wherein the molar ratio of hexanediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1.08:0.07:4.2:27;

[0145] The chemical structure of the prepared prepolymer is as follows:

[0146] ;

[0147] (6) the prepolymer is transferred into a polycondensation kettle, vacuum is drawn to-0.05MPa, and reaction is carried out at 216°C for 4h, and then the material is discharged from an extruder at 304°C, and the particles are cut, and PA6Z resin, i.e. semi-aromatic polyamide material, is obtained.

[0148] The chemical structure of the prepared semi-aromatic polyamide material is:

[0149] ;

[0150] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption of the semi-aromatic polyamide material is 0.27%, the linear expansion coefficient is 13.7 ppm / ℃, the melt index is 73 g / 10 min, the initial degradation temperature is 457℃, and the heat distortion temperature is 277℃; the tensile strength of the semi-aromatic polyamide material is 58 MPa, the elongation at break is 4.3%, the bending strength is 105 MPa, the bending modulus is 3300 MPa, and the impact strength is 7.1 KJ / m 2 .

[0151] Example 6

[0152] A method for preparing a semi-aromatic polyamide material, the specific steps are as follows:

[0153] (1) Preparation of raw materials:

[0154] 1,5-hexadiyne (CAS 628-16-0); NaN3 (CAS 26628-22-8); the catalyst is CuBr; the solvent I is isopropyl alcohol; CeCl3·7H2O (CAS 18618-55-8); the substance X is RbI; the solvent II is N,N-dimethylformamide; terephthalic acid; distilled water; hexamethylenediamine; benzoic acid;

[0155] (2) 1,5-hexadiyne, NaN3 and catalyst are added to solvent I, and the product A is obtained by click chemistry reaction at 50℃ for 12h; wherein the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:4:50:0.5;

[0156] (3) Product A, CeCl3·7H2O and substance X are added to solvent II, and 6Q monomer is obtained by reacting at 80℃ for 24h; wherein the molar ratio of product A, CeCl3·7H2O, substance X and solvent II is 1:3.6:24:1000;

[0157] The chemical structure of the prepared 6Q monomer is .

[0158] (4) 6Q monomer, terephthalic acid and distilled water are added into a normal pressure reaction kettle, and after constant temperature reaction at 80°C for 1 hour, the pH value of the solution is adjusted to neutral, and after evaporation and concentration, cooling crystallization is carried out, the filtrate is collected, and after drying in a vacuum oven at 105°C, PA6Q salt powder is obtained; wherein the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.11:4;

[0159] (5) Hexamethylene diamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added into a reaction kettle, argon is blown for 30 min, then the kettle is filled with argon to 0.4 MPa, and heating is started under stirring, when the pressure in the kettle reaches 3 MPa, the argon filling is stopped, the excess water vapor is discharged, and the pressure in the kettle is kept stable, when the temperature in the kettle reaches 250°C, the pressure is kept at this temperature for 1.5 h to obtain a prepolymer; wherein the molar ratio of hexamethylene diamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1.1:0.05:5:30;

[0160] The chemical structure of the prepared prepolymer is as follows:

[0161] ;

[0162] (6) The prepolymer is transferred into a polycondensation kettle, vacuumized to-0.04 MPa, and reacted at 220°C for 4 h, and then the material is discharged from the extruder at 308°C and cut into particles to obtain PA6Z resin, i.e. a semi-aromatic polyamide material.

[0163] The chemical structure of the prepared semi-aromatic polyamide material is as follows:

[0164] ;

[0165] The semi-aromatic polyamide material is insoluble in formic acid, toluene, methanol, chloroform, tetrachloromethane, N,N-dimethylformamide, dimethyl sulfoxide and pyridine; the water absorption of the semi-aromatic polyamide material is 0.3%, the linear expansion coefficient is 14 ppm / °C, the melt index is 80 g / 10 min, the initial degradation temperature is 460°C, and the heat distortion temperature is 300°C; the tensile strength of the semi-aromatic polyamide material is 60 MPa, the elongation at break is 4.5%, the bending strength is 106 MPa, the bending modulus is 3600 MPa, and the impact strength is 7.6 KJ / m 2 .

[0166] Example 7

[0167] A preparation method of a semi-aromatic polyamide-based composite material, and the specific steps are as follows:

[0168] (1) Preparation of raw materials:

[0169] The PA6Z resin is the PA6Z resin of Example 1.

[0170] The reinforcing material is glass fiber.

[0171] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 70℃ for 72h, and then the composite material is obtained by extrusion and granulation in sequence; wherein the extrusion temperature is 290℃, the extrusion rate is 50r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:0.05.

[0172] The semi-aromatic polyamide-based composite material prepared has a melt index of 20g / 10min, an initial degradation temperature of 470℃, a heat distortion temperature of 290℃, a tensile strength of 100MPa, an elongation at break of 3.1%, a bending strength of 140MPa, a bending modulus of 5800MPa, and an impact strength of 6.9KJ / m 2 .

[0173] Example 8

[0174] A preparation method of a semi-aromatic polyamide-based composite material, the specific steps are as follows:

[0175] (1) Preparation of raw materials:

[0176] The PA6Z resin is the PA6Z resin of Example 2.

[0177] The reinforcing material is glass fiber.

[0178] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 72℃ for 60h, and then the composite material is obtained by extrusion and granulation in sequence; wherein the extrusion temperature is 292℃, the extrusion rate is 45r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:0.15.

[0179] The semi-aromatic polyamide-based composite material prepared has a melt index of 24g / 10min, an initial degradation temperature of 475℃, a heat distortion temperature of 300℃, a tensile strength of 130MPa, an elongation at break of 3.3%, a bending strength of 170MPa, a bending modulus of 7100MPa, and an impact strength of 7.2KJ / m 2 .

[0180] Example 9

[0181] A preparation method of a semi-aromatic polyamide-based composite material, the specific steps are as follows:

[0182] (1) Preparation of raw materials:

[0183] The PA6Z resin is the PA6Z resin of Example 3.

[0184] The reinforcing material is glass fiber;

[0185] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 74 ℃ for 50 h, and the composite material is obtained by extrusion and pelletization in sequence; wherein the extrusion temperature is 294 ℃, the extrusion rate is 40 r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:0.35.

[0186] The prepared semi-aromatic polyamide-based composite material has a melt index of 28 g / 10 min, an initial degradation temperature of 480 ℃, a heat distortion temperature of 310 ℃, a tensile strength of 160 MPa, an elongation at break of 3.5%, a bending strength of 200 MPa, a bending modulus of 9800 MPa, and an impact strength of 7.7 KJ / m 2 .

[0187] Example 10

[0188] A preparation method of a semi-aromatic polyamide-based composite material, and the specific steps are as follows:

[0189] (1) Preparation of raw materials:

[0190] The PA6Z resin is the PA6Z resin of Example 4;

[0191] The reinforcing material is carbon fiber;

[0192] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 76 ℃ for 40 h, and the composite material is obtained by extrusion and pelletization in sequence; wherein the extrusion temperature is 298 ℃, the extrusion rate is 35 r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:0.5.

[0193] The prepared semi-aromatic polyamide-based composite material has a melt index of 32 g / 10 min, an initial degradation temperature of 483 ℃, a heat distortion temperature of 320 ℃, a tensile strength of 190 MPa, an elongation at break of 3.6%, a bending strength of 230 MPa, a bending modulus of 11600 MPa, and an impact strength of 8 KJ / m 2 .

[0194] Example 11

[0195] A preparation method of a semi-aromatic polyamide-based composite material, and the specific steps are as follows:

[0196] (1) Preparation of raw materials:

[0197] The PA6Z resin is the PA6Z resin of Example 5;

[0198] The reinforcing material is carbon fiber;

[0199] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 78℃ for 30h, and the composite material is obtained by extrusion and granulation in sequence; wherein the extrusion temperature is 305℃, the extrusion rate is 33r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:0.75.

[0200] The prepared semi-aromatic polyamide-based composite material has a melt index of 35g / 10min, an initial degradation temperature of 487℃, a heat distortion temperature of 330℃, a tensile strength of 220MPa, an elongation at break of 3.8%, a bending strength of 260MPa, a bending modulus of 14100MPa, and an impact strength of 8.5KJ / m 2 .

[0201] Example 12

[0202] A preparation method of a semi-aromatic polyamide-based composite material, and the specific steps are as follows:

[0203] (1) Preparation of raw materials:

[0204] The PA6Z resin is the PA6Z resin of Example 6;

[0205] The reinforcing material is carbon fiber;

[0206] (2) The PA6Z resin is mixed with the reinforcing material after being vacuum dried at 80℃ for 24h, and the composite material is obtained by extrusion and granulation in sequence; wherein the extrusion temperature is 310℃, the extrusion rate is 30r / min; the mass ratio of the PA6Z resin after vacuum drying and the reinforcing material is 1:1.

[0207] The prepared semi-aromatic polyamide-based composite material has a melt index of 38g / 10min, an initial degradation temperature of 490℃, a heat distortion temperature of 340℃, a tensile strength of 250MPa, an elongation at break of 3.9%, a bending strength of 280MPa, a bending modulus of 16800MPa, and an impact strength of 8.9KJ / m 2 .

Claims

1. A method for preparing a semi-aromatic polyamide-based composite material, characterized in that: The PA6Z resin is vacuum dried and then mixed with the reinforcement material, and then extruded and pelletized to obtain a composite material; The chemical structure of PA6Z resin is as follows: Where x>0, y>0, x+y=1, 40≤n≤500; The specific preparation process of PA6Z resin is as follows: (1) 1,5-Hexadiyne, NaN3, and a catalyst are added to solvent I and subjected to a click chemistry reaction at 40-50°C for 12-24 hours to obtain product A; (2) Product A, CeCl3·7H2O, and substance X are added to solvent II and reacted at 60-80°C for 24-48 hours to obtain 6Q monomer; substance X is NaI, KI, or RbI; (3) Adding 6Q monomer, terephthalic acid and distilled water into a normal pressure reactor, reacting at a constant temperature of 70-80°C for 2-5 hours, adjusting the pH value of the solution to neutral, evaporating and concentrating, cooling and crystallizing, filtering and collecting the mother liquor, and drying in a vacuum oven at 101-105°C to obtain PA6Q salt powder; The chemical structure of 6Q monomer is (4) Hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water are added to a reactor, and an inert gas is purged for 10 to 30 minutes. Subsequently, the inert gas is filled into the reactor to 0.4 to 0.6 MPa, and heating is started under stirring. When the pressure in the reactor reaches 2.0 to 3.0 MPa, the inert gas is stopped, excess water vapor is discharged and the pressure in the reactor is maintained stable. When the temperature in the reactor reaches 200 to 250° C., the reaction is carried out at this temperature for 1.5 to 5 hours to obtain a prepolymer; (5) The prepolymer is transferred into a polycondensation reactor, vacuumed to -0.11 to -0.04 MPa, reacted at 200 to 220°C for 4 to 8 hours, discharged through an extruder at 290 to 308°C, and pelletized to obtain PA6Z resin; In step (1), solvent I is methanol, ethanol or isopropanol, the catalyst is CuI or CuBr, and the molar ratio of 1,5-hexadiyne, NaN3, solvent I and catalyst is 1:2.5-4:10-50:0.1-0.5; In step (2), solvent II is acetonitrile, tetrahydrofuran, N,N-dimethylformamide or dimethyl sulfoxide, and the molar ratio of product A, CeCl3·7H2O, substance X and solvent II is 1:3-3.6:18-24:200-1000; In step (3), the molar ratio of 6Q monomer, terephthalic acid and distilled water is 1:1.01-1.11:2-4; In step (4), the inert gas is helium or argon, and the molar ratio of hexamethylenediamine, terephthalic acid, benzoic acid, PA6Q salt and distilled water is 1:1-1.1:0.05-0.15:2-5:10-30.

2. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, wherein: The vacuum drying temperature is 70-80°C and the time is 24-72 hours.

3. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, wherein: The reinforcement material is glass fiber or carbon fiber.

4. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, wherein: The extrusion temperature is 290-310°C, and the extrusion rate is 30-50 r / min.

5. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, wherein: The mass ratio of the vacuum-dried PA6Z resin to the reinforcement material is 1:0.05-1.

6. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, characterized in that: The semi-aromatic polyamide-based composite material has a melt index of 20 to 38 g / 10 min, an initial degradation temperature of 470 to 490 ° C, a heat deformation temperature of 290 to 340 ° C, a tensile strength of 100 to 250 MPa, an elongation at break of 3.1% to 3.9%, a flexural strength of 140 to 280 MPa, a flexural modulus of 5800 to 16800 MPa, and an impact strength of 6.9 to 8.9 KJ / m 2 .

7. The method for preparing a semi-aromatic polyamide-based composite material according to claim 1, characterized in that: The chemical structure of the prepolymer in step (4) is as follows: Among them, x>0, y>0, x+y=1, m≤40.

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