A modified PA66 material, its preparation method and application

Abstract

This invention provides a modified PA66 material, comprising: a PA66 resin matrix; an amorphous polyarylene ether resin; and a compatibilizer; wherein the amorphous polyarylene ether resin comprises structural units —A—, —B—, —C—, and —D—; —A— is [missing information]; —B— is [missing information]; —C— is [missing information]; —D— is [missing information]; wherein a, b, c, and d are the mole fractions of structural units —A—, —B—, —C—, and —D—, respectively, satisfying a+b+c+d=1, a>0, d>0, 0≤b<1, 0≤c<1. The modified PA66 material provided by this invention possesses excellent mechanical properties, heat resistance, and low warpage characteristics, meeting the comprehensive requirements of FDM 3D printing for material rheological properties, dimensional stability, and molding quality.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a modified PA66 material, its preparation method, and its application. Background Technology

[0002] Since its inception in the 1980s, 3D printing technology has evolved from an initial conceptual manufacturing method into an advanced manufacturing technology with significant industrial value. With continuous improvements in material systems and molding processes, 3D printing has demonstrated significant advantages in rapid prototyping, personalized manufacturing, and integrated manufacturing of complex structures. Currently, 3D printing technology is widely used in various fields such as biomedicine, aerospace, automotive manufacturing, and personalized customization.

[0003] Among the many 3D printing processes, Fused Deposition Modeling (FDM) technology has become one of the most widely researched and applied 3D printing technologies due to its relatively simple equipment structure, stable molding process, wide range of applicable materials, and low manufacturing cost. FDM technology heats and melts thermoplastic materials and deposits them layer by layer to form a 3D printing process. The quality of the 3D printing process largely depends on the thermal properties, rheological properties, and crystallization behavior of the materials used.

[0004] Material properties are one of the key factors affecting the molding quality, mechanical properties, and application range of FDM. Existing FDM printing materials cover multiple categories, including general-purpose plastics, engineering plastics, and specialty engineering plastics. General-purpose plastics typically possess good printability and molding stability, but their mechanical and heat resistance properties are limited. While specialty engineering plastics exhibit excellent heat resistance and mechanical properties, they often require sophisticated printing equipment and process conditions, and their material costs are high, thus limiting their widespread application in engineering fields to some extent. Therefore, achieving a balance between material properties and processing adaptability while ensuring good printability is of great significance.

[0005] Polyamide (PA) is a class of thermoplastic polymers containing amide bonds in their molecular chains. It possesses excellent processing properties, superior mechanical properties, wear resistance, and chemical stability, and has been widely used in the automotive industry, electronics and electrical engineering, machinery manufacturing, and engineering structural components. Polyamide materials are also suitable for FDM 3D printing, with PA6, PA12, and fiber-reinforced polyamide materials already achieving relatively mature applications.

[0006] As one of the most widely used polyamide materials, PA66 has higher heat resistance and better mechanical properties compared to PA6 and PA12, but its application in FDM 3D printing is still somewhat limited. On the one hand, PA66 has a regular molecular chain structure and high crystallinity, which leads to uneven cooling and crystallization shrinkage during printing, easily causing warping and deformation, thus affecting the dimensional accuracy and molding stability of the parts. On the other hand, PA66 has a narrow processing window in the molten state, and when the processing temperature exceeds its melting point, the melt viscosity tends to decrease rapidly, which is not conducive to the stable preparation of printing filaments and the precise control of the printing process.

[0007] Currently, research on the application of PA66 in FDM 3D printing mainly focuses on compounding it with other nylon materials or improving its molding performance and warpage by introducing fillers and fibers. For example, patents "A Modified Nylon 3D Printing Material and Its Preparation Method" (authorization publication number CN107523046A) and "A High-Strength Metal Fiber Reinforced Nylon 3D Printing Material and Its Preparation Method" (authorization publication number CN107573681A) both improve the printing performance of nylon materials by introducing other components or reinforcing materials. However, these methods often suffer from problems such as complex material systems, increased processing difficulty, or high costs.

[0008] Therefore, developing a modified PA66 material that combines excellent mechanical properties, heat resistance, and low warpage characteristics is of great practical significance for expanding the FDM 3D printing material system and promoting the application of high-performance engineering plastics in complex structures and functional components. Summary of the Invention

[0009] This invention aims to address the shortcomings of existing PA66 materials in fused deposition modeling (FDM) 3D printing by providing a modified PA66 material, its preparation method, and its applications. The purpose of this invention is to provide a modified PA66 material with excellent mechanical properties, heat resistance, and low warpage characteristics. This material is suitable for FDM 3D printing, expanding the application of high-performance engineering plastics in complex structures and functional components while ensuring good printability and molding stability.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a modified PA66 material, the modified PA66 material comprising: PA66 resin matrix; amorphous polyarylene ether resin; and compatibilizer; The amorphous polyarylene ether resin includes structural units —A—, —B—, —C— and —D—. —A—for —B—for —C—for ;—D—for ; Where a, b, c, and d are the mole fractions of structural units —A—, —B—, —C—, and —D—, respectively, satisfying a+b+c+d=1, a>0, d>0, 0≤b<1, and 0≤c<1.

[0011] This invention introduces amorphous polyarylene ether resin into the PA66 resin matrix, effectively suppressing the crystallization behavior of PA66 during the cooling process, reducing its crystallinity and crystallization rate, thereby significantly reducing the material's coefficient of linear expansion (CTE) and thermal shrinkage rate. This effectively suppresses warping deformation caused by uneven crystallization shrinkage during FDM 3D printing, improving the dimensional stability and molding accuracy of the printed parts. The amorphous polyarylene ether resin used has excellent heat resistance and mechanical strength, and can achieve good melt blending with PA66. It does not require complex chemical modification or special processing conditions, and the processing technology is simple and highly operable. By modifying PA66 with this amorphous polyarylene ether, the resulting material maintains good processing performance while significantly improving tensile strength, elongation at break, and heat resistance. The introduction of a compatibilizer significantly improves the interfacial compatibility between PA66 and the amorphous polyarylene ether resin, enhances the interfacial bonding strength between the two phases, and further improves the overall mechanical properties and melt processing stability of the modified PA66 material. This avoids nozzle clogging or filament breakage caused by phase separation, which is beneficial for the continuous and stable preparation of FDM 3D printing filaments.

[0012] The amorphous polyarylene ether resin of the present invention comprises structural units —A—, —B—, —C—, and —D—. The diazanaphthone heterocycle in structural unit —A— has a rigid and twisted non-coplanar structure, which can significantly increase the glass transition temperature (T0) of the polymer. gThe process imparts excellent heat resistance to the material while disrupting the regularity of the molecular chain, causing the polyarylene ether resin to exhibit an amorphous form. This effectively inhibits the crystallization behavior of PA66 after blending, reducing warpage during printing. Structural unit B contains a rigid conjugated backbone (i.e., a triphenyl diketone structure) formed by three benzene rings linked by alternating ketone groups. This high rigidity significantly improves the polymer's modulus and mechanical strength. When the amorphous polyarylene ether resin is blended with PA66, the rigid segments effectively bear stress, significantly enhancing the tensile strength of the modified material. Simultaneously, the ketone groups may form weak hydrogen bonds with the PA66 amide groups, further strengthening the interfacial bonding. The cyano group in structural unit C is a strongly polar group that can form strong hydrogen bonds or dipole-dipole interactions with the amide groups in the PA66 molecular chain. This significantly improves the compatibility between the amorphous polyarylene ether resin and PA66, resulting in tight interfacial bonding and effective stress transfer, helping to maintain good elongation at break while improving strength. The aryl ether bonds in the structural unit —D— impart a certain degree of flexibility to the molecular chain, which can reduce the processing viscosity of the polymer melt, improve fluidity, make the amorphous polyaryl ether resin and PA66 more uniformly dispersed during melt blending, and facilitate subsequent extrusion and filament preparation of FDM printing filaments, ultimately controlling the melt index of the modified material within a suitable range for printing.

[0013] Furthermore, the amorphous polyarylether resin has a structure as shown in Formula I or Formula II:

[0014] Formula I

[0015] Formula II, x: y= (0.2-1): 1.

[0016] Furthermore, by weight percentage, the modified PA66 material comprises: 60%-88% PA66, 10%-30% amorphous polyarylene ether resin, and 2%-10% compatibilizer, and the sum of the weight percentages of PA66, amorphous polyarylene ether resin, and compatibilizer is 100%.

[0017] Furthermore, at 280℃ and a load of 1.2 kg, the melt flow index of the modified PA66 material was measured to be 8-20 g / 10 min.

[0018] Furthermore, the number-average molecular weight of the amorphous polyarylene ether resin is 20 kDa-50 kDa.

[0019] Furthermore, the compatibilizer is selected from one or more of polyetherimide or maleic anhydride grafted compatibilizers.

[0020] Furthermore, the preparation method of the amorphous polyarylene ether resin includes: adding bisphenol monomer, dihalogen monomer, alkaline catalyst and dehydrating agent to a polymerization solvent, heating under nitrogen protection until the dehydrating agent is refluxed and reacting for 1-4 h; after the dehydrating agent is removed, continuing to heat to 180-200℃ and reacting for 4-6 h to obtain the amorphous polyarylene ether resin.

[0021] Furthermore, the bisphenol monomer is 4-(4-hydroxyphenyl)-2,3-diazanaphth-1-one and hydroquinone.

[0022] Furthermore, the dihalogenated monomer is one or both of difluorobenzonitrile and 1,4-bis(4-fluorobenzoyl)benzene.

[0023] Furthermore, the molar ratio of the bisphenol monomer to the dihalo monomer is (0.8-1.2):1.

[0024] Furthermore, the polymerization solvent is selected from one or both of sulfolane and N-methylpyrrolidone.

[0025] Furthermore, the mass ratio of the polymerization solvent to the total mass of bisphenol monomer and dihalogen monomer is (1-2.5):1.

[0026] Furthermore, the dehydrating agent is selected from one or both of toluene and xylene.

[0027] Furthermore, the volume ratio of the dehydrating agent to the polymerization solvent is (1.5-2.5):1.

[0028] Furthermore, the alkaline catalyst is selected from one or more of K2CO3, Na2CO3, and CaCO3.

[0029] Furthermore, the molar ratio of the alkaline catalyst to the dihalogen monomer is (1.1-1.7):1.

[0030] Secondly, the present invention provides a method for preparing a modified PA66 material, the method comprising the following steps: a) After thoroughly drying PA66, amorphous polyarylene ether resin and compatibilizer at 80-120 ℃, they are mixed according to the formula ratio to obtain a mixture; b) The mixture is fed into an extruder for melt blending and granulation, wherein the extruder is heated to 250-300°C, and after cooling, it is granulated to obtain blended granules; c) The blended granules are extruded and drawn into fibers using an extruder, wherein the extruder barrel temperature is 250-300 ℃, and then drawn and cooled by a traction machine to obtain the modified PA66 material.

[0031] Furthermore, the extruder mentioned in step b) is a twin-screw extruder, the cooling method is air cooling, the screw speed of the extruder is 80-200 rpm, and the feeder speed is 10-30 rpm.

[0032] Furthermore, the extruder mentioned in step c) is a twin-screw extruder, the cooling method is air cooling, the screw speed of the extruder is 80-200 rpm, and the feeder speed is 10-30 rpm.

[0033] Furthermore, in step c), the speed of the tractor is 50-100 rpm.

[0034] Thirdly, the present invention provides an application of the modified PA66 material according to the first aspect or the modified PA66 material prepared according to the preparation method of the second aspect in 3D printing.

[0035] This invention provides a modified PA66 material, its preparation method, and its applications. Compared with the prior art, the beneficial effects of this invention include at least one of the following: (1) By introducing amorphous polyarylene ether resin into the PA66 resin matrix, the present invention effectively inhibits the crystallization behavior of PA66 during the cooling process, reduces its crystallinity and crystallization rate, thereby significantly reducing the linear expansion coefficient (CTE) and thermal shrinkage rate of the material, and thus effectively inhibits the warping deformation caused by uneven crystallization shrinkage during FDM 3D printing, and improves the dimensional stability and molding accuracy of the printed parts. (2) The amorphous polyarylene ether resin used in this invention has excellent heat resistance and mechanical strength, and can achieve good melt blending with PA66. It does not require complex chemical modification or special processing conditions, and the processing technology is simple and highly operable. Through the modification of PA66 by this amorphous polyarylene ether, the resulting material significantly improves tensile strength, elongation at break and heat resistance while maintaining good processing performance; (3) The present invention introduces a compatibilizer, which significantly improves the interfacial compatibility between PA66 and amorphous polyarylether resin, enhances the interfacial bonding strength between the two phases, thereby further improving the overall mechanical properties and melt processing stability of the modified PA66 material, which is conducive to the continuous and stable preparation of FDM 3D printing filaments; (4) In summary, the modified PA66 material provided by the present invention has excellent mechanical properties, heat resistance and low warpage characteristics, which can meet the comprehensive requirements of FDM 3D printing for material rheological properties, dimensional stability and molding quality, and has good industrial application prospects. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0037] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0038] In a first aspect, the present invention provides a modified PA66 material, the modified PA66 material comprising: PA66 resin matrix; amorphous polyarylene ether resin; and compatibilizer; The amorphous polyarylene ether resin includes structural units —A—, —B—, —C— and —D—. —A—for —B—for —C—for ;—D—for ; Where a, b, c, and d are the mole fractions of structural units —A—, —B—, —C—, and —D—, respectively, satisfying a+b+c+d=1, a>0, d>0, 0≤b<1, and 0≤c<1.

[0039] In this invention, a, b, c, and d represent the mole fractions (i.e., the amount of substance fractions) of structural units A, B, C, and D in all structural units, respectively. The mole fraction (also called the amount of substance fraction) is the ratio of the amount of substance of a particular structural unit to the total amount of substance of all structural units, used to represent the proportion of that structural unit in all structural units. The sum of the mole fractions of all structural units is 1.

[0040] This invention introduces amorphous polyarylene ether resin into the PA66 resin matrix, effectively suppressing the crystallization behavior of PA66 during the cooling process, reducing its crystallinity and crystallization rate, thereby significantly reducing the material's coefficient of linear expansion (CTE) and thermal shrinkage rate. This effectively suppresses warping deformation caused by uneven crystallization shrinkage during FDM 3D printing, improving the dimensional stability and molding accuracy of the printed parts. The amorphous polyarylene ether resin used has excellent heat resistance and mechanical strength, and can achieve good melt blending with PA66. It does not require complex chemical modification or special processing conditions, and the processing technology is simple and highly operable. By modifying PA66 with this amorphous polyarylene ether, the resulting material maintains good processing performance while significantly improving tensile strength, elongation at break, and heat resistance. The introduction of a compatibilizer significantly improves the interfacial compatibility between PA66 and the amorphous polyarylene ether resin, enhances the interfacial bonding strength between the two phases, and further improves the overall mechanical properties and melt processing stability of the modified PA66 material. This avoids nozzle clogging or filament breakage caused by phase separation, which is beneficial for the continuous and stable preparation of FDM 3D printing filaments.

[0041] The amorphous polyarylene ether resin of the present invention comprises structural units —A—, —B—, —C—, and —D—. The diazanaphthone heterocycle in structural unit —A— has a rigid and twisted non-coplanar structure, which can significantly increase the glass transition temperature (T0) of the polymer. g The process imparts excellent heat resistance to the material while disrupting the regularity of the molecular chain, causing the polyarylene ether resin to exhibit an amorphous form. This effectively inhibits the crystallization behavior of PA66 after blending, reducing warpage during printing. Structural unit B contains a rigid conjugated backbone (i.e., a triphenyl diketone structure) formed by three benzene rings linked by alternating ketone groups. This high rigidity significantly improves the polymer's modulus and mechanical strength. When the amorphous polyarylene ether resin is blended with PA66, the rigid segments effectively bear stress, significantly enhancing the tensile strength of the modified material. Simultaneously, the ketone groups may form weak hydrogen bonds with the PA66 amide groups, further strengthening the interfacial bonding. The cyano group in structural unit C is a strongly polar group that can form strong hydrogen bonds or dipole-dipole interactions with the amide groups in the PA66 molecular chain. This significantly improves the compatibility between the amorphous polyarylene ether resin and PA66, resulting in tight interfacial bonding and effective stress transfer, helping to maintain good elongation at break while improving strength. The aryl ether bonds in the structural unit —D— impart a certain degree of flexibility to the molecular chain, which can reduce the processing viscosity of the polymer melt, improve fluidity, make the amorphous polyaryl ether resin and PA66 more uniformly dispersed during melt blending, and facilitate subsequent extrusion and filament preparation of FDM printing filaments, ultimately controlling the melt index of the modified material within a suitable range for printing.

[0042] As an alternative embodiment, the amorphous polyarylether resin has a structure as shown in Formula I or Formula II:

[0043] Formula I

[0044] Equation II, x:y = (0.2-1):1, can be, for example, 0.2:1, 0.3:1, 0.5:1, 0.6:1, 0.8:1 or 1:1.

[0045] This invention further specifies that the amorphous polyarylene ether resin has a specific structure shown in Formula I or Formula II. This specific polyarylene ether resin has a rigid framework and a large free volume, exhibiting a high degree of amorphization. When blended with PA66, it can more effectively disrupt the ordered arrangement of PA66 molecular chains, thereby significantly reducing crystallinity and CTE. The resins of Formula I and Formula II themselves contain heat-resistant structures such as triphenyl diketone and phenazine, resulting in high thermal decomposition temperatures. When blended with PA66, they can overall improve the T (temperature resistance) of the material. g and heat distortion temperature.

[0046] As an optional implementation, the modified PA66 material comprises, by weight percentage: 60%-88% PA66, for example, 60%, 65%, 70%, 75%, 77%, 80%, 85%, or 88%; 10%-30% amorphous polyarylene ether resin, for example, 10%, 15%, 20%, 25%, or 30%; and 2%-10% compatibilizer, for example, 2%, 3%, 5%, 6%, 8%, or 10%, wherein the sum of the weight percentages of PA66, amorphous polyarylene ether resin, and compatibilizer is 100%.

[0047] In this invention, when the PA66 content is below 60%, the melt flowability of the material may decrease; when it is above 88%, the warpage improvement effect is not significant. 10%-30% of amorphous polyarylether resin can significantly reduce CTE and increase T. g At the same time, it maintains the original good processability of PA66. 2%-10% compatibilizer can form an effective interfacial bond, while excessive amount may reduce mechanical properties.

[0048] As an optional implementation, the melt flow index of the modified PA66 material was measured to be 8-20 g / 10 min at 280°C and 1.2 kg load, for example, it could be 8 g / 10 min, 9.1 g / 10 min, 10 g / 10 min, 10.7 g / 10 min, 12 g / 10 min, 12.5 g / 10 min, 13.4 g / 10 min, 15 g / 10 min, 18 g / 10 min or 20 g / 10 min.

[0049] The modified PA66 material of this invention has a melt flow index of 8-20 g / 10 min (280℃ / 1.2kg). The melt flow within this range can ensure smooth extrusion of the filament and maintain interlayer bonding during printing.

[0050] As an optional embodiment, the number average molecular weight of the amorphous polyarylether resin is 20 kDa-50 kDa, for example, it can be 20 kDa, 21 kDa, 25 kDa, 30 kDa, 35 kDa, 38 kDa, 40 kDa, 45 kDa or 50 kDa.

[0051] As an optional implementation, the compatibilizer is selected from one or more of polyetherimide or maleic anhydride grafted compatibilizers.

[0052] In this invention, when the molecular weight is below 20 kDa, the resin's mechanical strength and heat resistance are insufficient; when it is above 50 kDa, the melt viscosity is too high, making blending with PA66 difficult and causing filament breakage during extrusion. Polyetherimide (PEI) and maleic anhydride grafted compatibilizers (such as MAH-g-POE, MAH-g-PS, etc.) contain active groups that react with the end groups (amino and carboxyl groups) of PA66, or have good affinity with amorphous polyaryl ether resins. They can reduce the interfacial tension between the two phases, refine the dispersed phase size, and enhance the interfacial bonding force.

[0053] As an optional embodiment, the preparation method of the amorphous polyarylene ether resin includes: adding bisphenol monomer, dihalogen monomer, alkaline catalyst and dehydrating agent to a polymerization solvent, heating under nitrogen protection until the dehydrating agent is refluxed and reacting for 1-4 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h or 4 h; after the dehydrating agent is removed, continuing to heat to 180-200℃, for example, 180℃, 185℃, 190℃, 195℃ or 200℃ and reacting for 4-6 h, for example, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, to obtain the amorphous polyarylene ether resin.

[0054] This invention removes the water generated during the reaction by refluxing a dehydrating agent, thereby promoting the forward polymerization reaction.

[0055] As an optional embodiment, the bisphenol monomer is 4-(4-hydroxyphenyl)-2,3-diazanaphth-1-one and hydroquinone.

[0056] As an optional implementation, the dihalogenated monomer is one or both of difluorobenzonitrile and 1,4-bis(4-fluorobenzoyl)benzene.

[0057] As an optional implementation, the molar ratio of the bisphenol monomer and the dihalogen monomer is (0.8-1.2):1, for example, it can be 0.8:1, 0.9:1, 1.0:1, 1.1:1 or 1.2:1.

[0058] In this invention, 4-(4-hydroxyphenyl)-2,3-diazanaphthyl-1-one contains a distorted, non-coplanar naphthone structure, which increases the rigidity of the molecular chain and disrupts its regularity, resulting in an amorphous resin. Hydroquinone regulates the resin's heat resistance and flowability. Difluorobenzonitrile and 1,4-bis(4-fluorobenzoyl)benzene are both reactive aryl fluorides, readily undergoing nucleophilic substitution reactions, significantly improving the polymer's modulus and mechanical strength. By adjusting the feed ratio of bisphenol to dihalogen monomers, the composition and molecular weight of the copolymer can be controlled, thereby regulating the resin's glass transition temperature and solubility.

[0059] As an alternative embodiment, the polymerization solvent is selected from one or both of sulfolane and N-methylpyrrolidone.

[0060] As an optional implementation, the mass ratio of the polymerization solvent to the total mass of bisphenol monomer and dihalogen monomer is (1-2.5):1, for example, it can be 1:1, 1.01:1, 1.21:1, 1.5:1, 2:1 or 2.5:1.

[0061] As an optional implementation, the dehydrating agent is selected from one or both of toluene and xylene.

[0062] As an optional implementation, the volume ratio of the dehydrating agent to the polymerization solvent is (1.5-2.5):1, for example, it can be 1.5:1, 2:1 or 2.5:1.

[0063] As an alternative embodiment, the alkaline catalyst is selected from one or more of K2CO3, Na2CO3 and CaCO3.

[0064] As an optional embodiment, the molar ratio of the alkaline catalyst to the dihalogen monomer is (1.1-1.7):1, for example, it can be 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1 or 1.7:1.

[0065] In this invention, sulfolane and N-methylpyrrolidone (NMP) exhibit good solubility for both reactants and products, ensuring homogeneous reaction and preventing polymer precipitation that could terminate the reaction. A solvent-to-monomer mass ratio of 1-2.5:1 ensures a suitable reaction concentration. Azeotropic mixing of toluene or xylene with water effectively removes water generated during the reaction, preventing hydrolysis of the alkaline catalyst and avoiding side reactions caused by water. Weakly basic carbonates such as K₂CO₃, Na₂CO₃, and CaCO₃ activate phenolic hydroxyl groups without excessively inducing halogen substitution side reactions. Under these reaction conditions, the polymerization reaction is stable, the product molecular weight is controllable (20-50 kDa), and the purified resin has low residual metal ions, making it suitable for subsequent blending with PA66 to prepare high-performance 3D printing materials.

[0066] Secondly, the present invention provides a method for preparing a modified PA66 material, the method comprising the following steps: a) After thoroughly drying PA66, amorphous polyarylene ether resin and compatibilizer at 80-120 ℃, they are mixed according to the formula ratio to obtain a mixture; b) The mixture is fed into an extruder for melt blending and granulation, wherein the extruder is heated to 250-300°C, and after cooling, it is granulated to obtain blended granules; c) The blended granules are extruded and drawn into fibers using an extruder, wherein the extruder barrel temperature is 250-300 ℃, and then drawn and cooled by a traction machine to obtain the modified PA66 material.

[0067] In this invention, both PA66 and amorphous polyarylether resin are prone to absorbing water. Thorough drying at 80-120℃ can avoid hydrolytic degradation caused by moisture during high-temperature extrusion, thus ensuring the mechanical properties of the material.

[0068] As an alternative implementation, in step a), PA66, amorphous polyarylene ether resin and compatibilizer are thoroughly dried at, for example, 80°C, 90°C, 100°C, 110°C or 120°C.

[0069] As an optional implementation, in step b), the extruder heating temperature can be, for example, 250°C, 255°C, 260°C, 265°C, 270°C, 272°C, 275°C, 280°C, 285°C, 290°C, or 300°C.

[0070] As an optional implementation, in step c), the extruder barrel temperature can be, for example, 250°C, 255°C, 260°C, 265°C, 270°C, 272°C, 275°C, 280°C, 285°C, 290°C, or 300°C.

[0071] As an optional implementation, the extruder mentioned in step b) is a twin-screw extruder, the cooling method is air cooling, the screw speed of the extruder is 80-200 rpm, for example, 80 rpm, 100 rpm, 115 rpm, 120 rpm, 150 rpm, 180 rpm or 200 rpm, and the feeder speed is 10-30 rpm, for example, 10 rpm, 15 rpm, 15.5 rpm, 17 rpm, 20 rpm, 24 rpm, 25 rpm, 27 rpm or 30 rpm.

[0072] As an optional implementation, the extruder mentioned in step c) is a twin-screw extruder, the cooling method is air cooling, the screw speed of the extruder is 80-200 rpm, for example, 80 rpm, 100 rpm, 115 rpm, 120 rpm, 150 rpm, 180 rpm or 200 rpm, and the feeder speed is 10-30 rpm, for example, 10 rpm, 15 rpm, 15.5 rpm, 17 rpm, 20 rpm, 24 rpm, 25 rpm, 27 rpm or 30 rpm.

[0073] As an optional implementation, in step c), the speed of the traction machine is 50-100 rpm, for example, 50 rpm, 60 rpm, 67 rpm, 70 rpm, 80 rpm, 90 rpm or 100 rpm.

[0074] Compared to single-screw extruders, twin-screw extruders offer superior mixing and self-cleaning capabilities, making them particularly suitable for multi-component blending modifications. High shear force promotes reactive compatibilization between the compatibilizer and the two phases, refines the dispersed phase size, and improves material uniformity. Air cooling is used after filament extrusion to avoid water absorption on the filament surface (PA66 is highly hygroscopic), which can cause air bubbles and reduce interlayer bonding during printing. Air cooling also allows for slow cooling of the filament, reducing internal stress. In this invention, the extruder screw speed is 80-200 rpm, and the feeder speed is 10-30 rpm, ensuring uniform dispersion of all components in the molten state and maximizing the compatibilizer's effectiveness. The traction speed, combined with the extruder screw speed, determines the filament diameter to be 1.75±0.05 mm. Within the 50-100 rpm range, standard FDM filaments can be stably produced, ensuring stable filament feeding during printing.

[0075] The present invention will now be described in further detail with reference to specific embodiments and comparative examples.

[0076] Example 1 1. Preparation of amorphous polyarylene ether resins This embodiment provides an amorphous polyarylether resin having a structure as shown in Formula I (Formula I simultaneously includes four structural units: —A—, —B—, —C—, and —D—).

[0077]

[0078] Formula I Its preparation method is as follows: In a 2 L three-necked flask equipped with a mechanical stirrer, a water separator, and a nitrogen inlet, the following components were added sequentially: 120.87 g (0.375 mol) of the dihalogen monomer 1,4-bis(4-fluorobenzoyl)benzene (for introducing the -B- unit), 52.16 g (0.375 mol) of the dihalogen monomer 2,6-difluorobenzonitrile (for introducing the -C- unit), 107.21 g (0.45 mol) of the bisphenol monomer 4-(4-hydroxyphenyl)-2,3-diazanaphthyl-1-one (for introducing the -A- unit), 33.03 g (0.3 mol) of the bisphenol monomer hydroquinone (for introducing the -D- unit), 124.38 g (0.9 mol) of the alkaline catalyst K2CO3 (the molar ratio of the alkaline catalyst to the dihalogen monomer was 1.2:1), and 300 mL of the polymerization solvent sulfolane (approximately 378 g, totaling 313.27 g with the monomer). The mixture consists of 750 mL of xylene (the volume ratio of dehydrating agent to polymerization solvent is 2.5:1), and bisphenol monomer (both types combined) to dihalogen monomer (both types combined) in a molar ratio of (0.45+0.3):(0.375+0.375) = 0.75:0.75 = 1:1.

[0079] Under nitrogen protection, the mixture was heated to reflux with xylene (approximately 145°C) as a dehydrating agent and reacted for 3 hours to remove moisture. After the dehydrating agent was removed, the temperature was increased to 180°C and the reaction continued for 5 hours. The reaction was terminated when the viscosity of the system stabilized and no longer increased significantly. The resulting product was post-treated to obtain an amorphous polyarylene ether resin. Analysis showed that the resin had a number-average molecular weight of 21 kDa and exhibited an amorphous morphology.

[0080] 2. Preparation of modified PA66 materials This embodiment provides a modified PA66 material, comprising by weight percentage: 60% PA66 resin matrix, 30% of the above-mentioned amorphous polyarylether resin, and 10% compatibilizer (polyetherimide Ultem1000), which is produced by Saudi Basic Industries Corporation (SABIC).

[0081] Its preparation method is as follows: a) Dry PA66, amorphous polyarylene ether resin and compatibilizer (polyetherimide) thoroughly at 120°C for 6 hours, add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain a mixture.

[0082] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 250℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 260℃; the screw speed is 120 rpm; and the feeder speed is 27 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0083] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 260℃, 265℃, 270℃, 280℃, 285℃, 280℃, 270℃, and 260℃. The screw speed is 80 rpm, the feeder speed is 17 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm and cooled by air to obtain modified PA66 3D printing filament with an average diameter of 1.75 mm.

[0084] 3. Performance Testing The melt flow index of the modified PA66 material in this embodiment was measured to be 9.1 g / 10 min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the modified PA66 filament prepared above. The results showed that the tensile strength of the material was 62.8 MPa, the elongation at break was 13.7%, and the glass transition temperature (T0) was [not specified]. g The temperature is 97℃, and the coefficient of linear thermal expansion (CTE) is 99.69ppm / ℃. During the printing process, the material is extruded smoothly without nozzle clogging. The printed products have high dimensional accuracy, no obvious warping, and exhibit good mechanical properties, heat resistance, and low warping characteristics.

[0085] Example 2 1. Preparation of amorphous polyarylene ether resins This embodiment provides an amorphous polyarylene ether resin having a structure as shown in Formula II (Formula II contains three structural units: —A—, —B—, and —D—, but does not contain the —C— unit).

[0086]

[0087] Equation II, where x:y = 1:1.

[0088] Its preparation method is as follows: In a 2 L three-necked flask equipped with a mechanical stirrer, a water separator, and a nitrogen inlet, the following were added sequentially: 193.39 g (0.6 mol) of the dihalogen monomer 1,4-bis(4-fluorobenzoyl)benzene (for introducing the -B- unit), 85.77 g (0.36 mol) of the bisphenol monomer 4-(4-hydroxyphenyl)-2,3-diazanaphthyl-1-one (for introducing the -A- unit), 26.43 g (0.24 mol) of the bisphenol monomer hydroquinone (for introducing the -D- unit), 99.5 g (0.72 mol) of alkaline catalyst K2CO3 (the molar ratio of alkaline catalyst to dihalogen monomer was 1.2:1), 300 mL of polymerization solvent N-methylpyrrolidone (approximately 309 g, with a ratio to the total monomer mass of 305.59 g of approximately 1.01:1), and 750 mL of [unspecified solvent]. mL of dehydrating agent toluene (volume ratio of dehydrating agent to polymerization solvent is 750:300 = 2.5:1). The molar ratio of bisphenol monomer (both types combined) to dihalogen monomer is (0.36 + 0.24): 0.6 = 0.6: 0.6 = 1:1.

[0089] Under nitrogen protection, the temperature was raised to reflux with the dehydrating agent toluene (approximately 135°C) and reacted for 3 hours to remove moisture. After the dehydrating agent was removed, the temperature was further raised to 180°C and the reaction continued for 5.5 hours. The reaction was terminated when the viscosity of the system tended to stabilize and no longer increased significantly. The resulting product was post-processed to obtain an amorphous polyarylene ether resin. Analysis showed that the resin had a number-average molecular weight of 38 kDa and exhibited an amorphous morphology.

[0090] Preparation of modified PA66 materials This embodiment provides a modified PA66 material, comprising by weight percentage: 70% PA66 resin matrix, 20% of the above-mentioned amorphous polyarylene ether resin, and 10% compatibilizer (the same polyetherimide Ultem1000 as in Example 1).

[0091] Its preparation method is as follows: a) Dry PA66, amorphous polyarylene ether resin and compatibilizer (polyetherimide) thoroughly at 120°C for 6 hours, add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain a mixture.

[0092] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 255℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 265℃; the screw speed is 115 rpm; and the feeder speed is 24 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0093] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 265℃, 270℃, 280℃, 285℃, 285℃, 280℃, 272℃, and 265℃. The screw speed is 80 rpm, the feeder speed is 15.5 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm and cooled by air to obtain modified PA66 3D printing filament with an average diameter of 1.78 mm.

[0094] 3. Performance Testing The melt flow index of the modified PA66 material in this embodiment was measured to be 13.4 g / 10min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the modified PA66 filament prepared above. The results showed that the tensile strength of the material was 61.2 MPa, the elongation at break was 12.7%, and the glass transition temperature (T0) was [not specified]. g The temperature is 96℃, and the coefficient of linear thermal expansion (CTE) is 99.83 ppm / ℃. During the printing process, the material is extruded smoothly without nozzle clogging. The printed products have high dimensional accuracy, no obvious warping, and exhibit good mechanical properties, heat resistance, and low warping characteristics.

[0095] Example 3 This embodiment provides a modified PA66 material, which uses an amorphous polyarylene ether resin of Formula I, with maleic anhydride-grafted polystyrene (SMA) as a compatibilizer. By weight percentage, the PA66 resin matrix is ​​65%, the above-mentioned amorphous polyarylene ether resin is 30%, and the compatibilizer (SMA-700) is 5%. SMA-700 is produced by Jiaxing Huawen Chemical Co., Ltd.

[0096] 1. The amorphous polyarylether resin has the structure shown in Formula I, and its preparation method is the same as in Example 1.

[0097] 2. Preparation of modified PA66 materials Its preparation method is as follows: a) Dry PA66, amorphous polyarylene ether resin and compatibilizer (SMA) thoroughly at 120°C for 6 hours, add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain a mixture.

[0098] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 250℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 260℃; the screw speed is 120 rpm; and the feeder speed is 27 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0099] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 260℃, 265℃, 270℃, 280℃, 285℃, 280℃, 270℃, and 260℃. The screw speed is 80 rpm, the feeder speed is 17 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm and cooled by air to obtain modified PA66 3D printing filament with an average diameter of 1.80 mm.

[0100] The melt index of the modified PA66 material in this embodiment was measured to be 10.7 g / 10min at 280℃ and 1.2 kg load. The modified PA66 filament prepared above was tested using FDM 3D printing. The results showed that the tensile strength of the material was 59.4 MPa, the elongation at break was 11.2%, and the glass transition temperature (T0) was [not specified]. g The temperature is 96℃, and the coefficient of linear thermal expansion (CTE) is 101.86 ppm / ℃. During the printing process, the material is extruded smoothly without nozzle clogging. The printed products have high dimensional accuracy, no obvious warping, and exhibit good mechanical properties, heat resistance, and low warping characteristics.

[0101] Example 4 This embodiment provides a modified PA66 material, which uses an amorphous polyarylene ether resin of Formula II, maleic anhydride-grafted polystyrene (SMA) as a compatibilizer, and by weight percentage, PA66 resin matrix is ​​77%, the above-mentioned amorphous polyarylene ether resin is 20%, and compatibilizer (SMA-700, the same as in Example 3) is 3%.

[0102] 1. The amorphous polyarylene ether resin has the structure shown in Formula II, and its preparation method is the same as in Example 2.

[0103] 2. Preparation of modified PA66 materials Its preparation method is as follows: a) Dry PA66, amorphous polyarylene ether resin and compatibilizer (SMA) thoroughly at 120°C for 6 hours, add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain a mixture.

[0104] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 255℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 265℃; the screw speed is 115 rpm; and the feeder speed is 24 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0105] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 265℃, 270℃, 280℃, 285℃, 285℃, 280℃, 272℃, and 265℃. The screw speed is 80 rpm, the feeder speed is 15.5 rpm, and the filament is drawn by a traction machine at a speed of 60 rpm and cooled by air cooling to obtain modified PA66 3D printing filament with an average diameter of 1.70 mm.

[0106] The melt index of the modified PA66 material in this embodiment was measured to be 12.5 g / 10min at 280℃ and 1.2 kg load. The modified PA66 filament prepared above was tested using FDM 3D printing. The results showed that the tensile strength of the material was 60.3 MPa, the elongation at break was 12.2%, and the glass transition temperature (T0) was [not specified]. g The temperature is 96℃, and the coefficient of linear thermal expansion (CTE) is 100.12 ppm / ℃. During the printing process, the material is extruded smoothly without nozzle clogging. The printed products have high dimensional accuracy, no obvious warping, and exhibit good mechanical properties, heat resistance, and low warping characteristics.

[0107] Comparative Example 1 This comparative example provides an unmodified pure PA66 material.

[0108] Its preparation method is as follows: a) Dry PA66 thoroughly at 120°C for 6 hours.

[0109] b) The dried PA66 was fed into a twin-screw extruder for melt granulation: the extruder heating temperature was set to 250℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 260℃; the screw speed was 120 rpm; and the feeder speed was 27 rpm. After extrusion, the material was air-cooled and pelletized to obtain pure PA66 granules.

[0110] c) The pure PA66 granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 260℃, 265℃, 270℃, 280℃, 285℃, 280℃, 270℃, and 260℃. The screw speed is 80 rpm, the feeder speed is 17 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm. It is then cooled and shaped by air cooling to obtain pure PA66 3D printing filament with an average diameter of 1.75 mm.

[0111] The melt index of the pure PA66 material in this comparative example was measured to be 43.8 g / 10 min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the pure PA66 filament prepared above. The results showed that the tensile strength of the material was 46.9 MPa, the elongation at break was 12.6%, and the glass transition temperature (T0) was [not specified]. g The temperature was 82℃, and the coefficient of linear thermal expansion (CTE) was 125.45ppm / ℃. During the printing process, although the material extrusion was relatively smooth, the product showed obvious warping and deformation, poor dimensional accuracy, and insufficient interlayer bonding.

[0112] Comparative Example 2 This comparative example provides a modified PA66 material comprising, by weight percentage: 80% PA66 resin matrix, 20% amorphous polyarylene ether resin, and containing no compatibilizer.

[0113] 1. The amorphous polyarylene ether resin has the structure shown in Formula II, and its preparation method is the same as in Example 2.

[0114] 2. Preparation of modified PA66 materials a) Dry PA66 and amorphous polyarylene ether resin thoroughly at 120°C for 6 hours, then add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain the mixture.

[0115] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 255℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 265℃; the screw speed is 115 rpm; and the feeder speed is 24 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0116] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 265℃, 270℃, 280℃, 285℃, 285℃, 280℃, 272℃, and 265℃. The screw speed is 80 rpm, the feeder speed is 15.5 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm and cooled by air cooling to obtain modified PA66 3D printing filament with an average diameter of 1.60 mm.

[0117] The melt flow index of the modified PA66 material in this comparative example was measured to be 20.4 g / 10min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the modified PA66 filament prepared above. The results showed that the tensile strength of the material was 45.1 MPa, the elongation at break was 10.4%, and the glass transition temperature (T0) was [not specified]. gThe temperature was 92℃, and the coefficient of linear thermal expansion (CTE) was 111.21 ppm / ℃. During the printing process, the material extrusion stability was poor, and nozzle clogging occasionally occurred. The surface of the printed product was rough, the interlayer bonding was weak, and there was still slight warping.

[0118] Comparative Example 3 This comparative example provides a modified PA66 material comprising, by weight percentage: 85% PA66 resin matrix, 5% amorphous polyarylene ether resin, and 10% compatibilizer (polyetherimide).

[0119] 1. The amorphous polyarylene ether resin has the structure shown in Formula I, and its preparation method is the same as in Example 1.

[0120] 2. Preparation of modified PA66 materials a) Dry PA66, amorphous polyarylene ether resin and polyetherimide thoroughly at 120°C for 6 hours, add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain a mixture.

[0121] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 250℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 260℃; the screw speed is 120 rpm; and the feeder speed is 27 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0122] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 260℃, 265℃, 270℃, 280℃, 285℃, 280℃, 270℃, and 260℃. The screw speed is 80 rpm, the feeder speed is 17 rpm, and the filament is drawn by a traction machine at a speed of 67 rpm and cooled by air cooling to obtain modified PA66 3D printing filament with an average diameter of 1.65 mm.

[0123] The melt flow index of the modified PA66 material in this comparative example was measured to be 19.4 g / 10 min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the modified PA66 filament prepared above. The results showed that the tensile strength of the material was 48.3 MPa, the elongation at break was 9.7%, and the glass transition temperature (T0) was [not specified]. g The temperature was 90℃, and the coefficient of linear thermal expansion (CTE) was 109.96 ppm / ℃. During the printing process, the material extrusion was acceptable, but the warping of the printed product was more pronounced than in Example 1, and the interlayer bonding strength and tensile strength were generally poor.

[0124] Comparative Example 4 This comparative example provides a modified PA66 material comprising, by weight percentage: 77% PA66 resin matrix, 20% liquid crystal polymer (LCP-MT1300), and 3% compatibilizer (SMA), wherein LCP-MT1300 is manufactured by Celanese.

[0125] 1. Preparation of modified PA66 materials Its preparation method is as follows: a) Dry PA66, LCP and SMA thoroughly at 120°C for 6 hours, then add them to a high-speed mixer according to the above formula ratio and mix for 5 minutes to obtain the mixture.

[0126] b) The mixture is fed into a twin-screw extruder for melt blending and granulation: the extruder heating temperature is set to 255℃, 260℃, 265℃, 265℃, 270℃, 270℃, 265℃, and 265℃; the screw speed is 115 rpm; and the feeder speed is 24 rpm. After extrusion, the mixture is air-cooled and then pelletized to obtain blended granules.

[0127] c) The blended granules are extruded again through a twin-screw extruder. The extruder barrel temperature is set to 265℃, 270℃, 280℃, 285℃, 285℃, 280℃, 272℃, and 265℃. The screw speed is 80 rpm, the feeder speed is 15.5 rpm, and the filament is drawn by a traction machine at a speed of 60 rpm and cooled by air cooling to obtain modified PA66 3D printing filament with an average diameter of 1.85 mm.

[0128] The melt flow index of the modified PA66 material in this comparative example was measured to be 25.6 g / 10min at 280℃ and 1.2 kg load. FDM 3D printing tests were conducted using the modified PA66 filament prepared above. The results showed that the tensile strength of the material was 42.6 MPa, the elongation at break was 12.7%, and the glass transition temperature (T0) was [not specified]. g The temperature was 85℃, and the coefficient of linear thermal expansion (CTE) was 114.43 ppm / ℃. During the printing process, the material extrusion was relatively smooth, but the printed products still showed obvious warping, poor dimensional accuracy, and limited improvement in heat resistance.

[0129] The tensile strengths of Examples 1-4 were all between 59.4 and 62.8 MPa, significantly higher than those of Comparative Example 1 (pure PA66, 46.9 MPa) and Comparative Examples 2-4 (42.6-48.3 MPa). This indicates that the rigid structural units of the amorphous polyarylene ether resin (especially the triphenylene diketone structure) can effectively bear stress and improve the tensile strength of the material. Among them, Example 1 had the highest tensile strength (62.8 MPa), which is related to its higher polyarylene ether resin content (30%) and the use of compatibilizer. In terms of elongation at break, Examples 1-4 were between 11.2% and 13.7%, comparable to or slightly better than pure PA66 (12.6%), indicating that the modification did not significantly sacrifice the toughness of the material. This is due to the compatibilizer improving the interfacial bonding between the two phases and the flexibility provided by the arylene bonds in the polyarylene ether resin.

[0130] Glass transition temperatures (T) of Examples 1-4 g The temperatures of both samples were 96-97℃, significantly higher than the 82℃ of pure PA66, indicating that the introduction of amorphous polyarylether resin effectively improved the heat resistance of the material. Comparative Examples 2-4 showed T... g The temperatures were 92℃, 90℃, and 85℃, respectively, all significantly lower than those in the examples, further confirming the role of the polyarylene ether resin structure (especially the A unit containing the diazanaphthone heterocycle) in improving T... g Its key role.

[0131] The CTE of pure PA66 was as high as 125.45 ppm / ℃, resulting in severe printing warping. The CTE of Examples 1-4 decreased to 99.69-101.86 ppm / ℃, a reduction of approximately 20%, with no significant warping in the printed products and good dimensional accuracy. This indicates that the amorphous polyarylene ether resin effectively inhibited the crystallization behavior of PA66 and reduced the heat shrinkage rate. Comparative Example 2 (without compatibilizer) had a CTE of 111.21 ppm / ℃, Comparative Example 3 (polyarylene ether resin content only 5%) had a CTE of 109.96 ppm / ℃, and Comparative Example 4 (LCP substitution) had a CTE of 114.43 ppm / ℃, all higher than the examples, demonstrating that the synergistic effect of sufficient amorphous polyarylene ether resin and compatibilizer is crucial for suppressing warping.

[0132] The melt index of pure PA66 is 43.8 g / 10 min, which is too high and unfavorable for printing control. The melt indexes of Examples 1-4 are 9.1-13.4 g / 10 min, which is within the suitable printing range of 8-20 g / 10 min, indicating that the introduction of amorphous polyarylene ether resin effectively controls the melt viscosity and ensures the stability of filament extrusion and printing. The melt indexes of Comparative Examples 2-4 are all higher than those of Examples (19.4-25.6 g / 10 min), further illustrating the advantages of the formulation of this invention in terms of flowability control. Comparing Example 2 (with compatibilizer, tensile strength 61.2 MPa, CTE 99.83 ppm / ℃) with Comparative Example 2 (without compatibilizer, tensile strength 45.1 MPa, CTE 111.21 ppm / ℃), it can be seen that the compatibilizer significantly improves the mechanical properties and interfacial bonding quality, reduces the coefficient of thermal expansion, and improves the extrusion stability during the printing process, avoiding nozzle clogging. In Examples 1-4, the polyarylene ether resin content was 20%-30%, exhibiting excellent performance. In Comparative Example 3, the content was only 5%, resulting in lower tensile strength (48.3 MPa) and lower Tg. g The tensile strength (90℃) decreased significantly, and the warpage remained noticeable, indicating that a sufficient amount of amorphous polyarylene ether resin is required to effectively inhibit crystallization and improve heat resistance and mechanical properties. Comparative Example 4 used a liquid crystal polymer (LCP) instead of the amorphous polyarylene ether resin of this invention, and its tensile strength (42.6 MPa) and T... g Both the temperature (85°C) and CTE (114.43 ppm / °C) were inferior to the examples, and printing warpage was still significant. This indicates that the amorphous polyarylether resin (containing A, B, C, and D structural units) with the specific structure of this invention has unique advantages in inhibiting crystallization and improving heat resistance and mechanical properties, which are incomparable to general-purpose high-performance polymers.

[0133] The modified PA66 materials in Examples 1-4 exhibited good tensile strength (59.4-62.8 MPa) and heat resistance (T0.05). g The performance of PA66 in FDM 3D printing is significantly better than that of Comparative Examples 1-4 in terms of temperature resistance (96-97℃), low warpage characteristics (CTE 99.69-101.86 ppm / ℃), and suitable melt flow index for printing (9.1-13.4 g / 10 min). Among them, Example 1 exhibits the best overall performance. This invention successfully solves the problems of severe warpage and poor dimensional accuracy of PA66 in FDM 3D printing by introducing a specific structure of amorphous polyarylether resin and compatibilizer, while maintaining excellent mechanical and heat resistance properties, showing good prospects for industrial application.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified PA66 material, characterized in that, The modified PA66 material includes: PA66 resin matrix; amorphous polyarylene ether resin; and compatibilizer; The amorphous polyarylene ether resin includes structural units —A—, —B—, —C— and —D—. —A— is ; —B— is ; —C— is ; —D— is ; Where a, b, c, and d are the mole fractions of structural units —A—, —B—, —C—, and —D—, respectively, satisfying a+b+c+d=1, a>0, d>0, 0≤b<1, and 0≤c<1.

2. The modified PA66 material according to claim 1, characterized in that, The amorphous polyarylene ether resin has a structure as shown in Formula I or Formula II: Formula I Formula II, x: y= (0.2-1):

1.

3. The modified PA66 material according to claim 1 or 2, characterized in that The modified PA66 material comprises, by weight percentage: 60%-88% PA66, 10%-30% amorphous polyarylene ether resin, and 2%-10% compatibilizer, wherein the sum of the weight percentages of PA66, amorphous polyarylene ether resin, and compatibilizer is 100%. And / or, at 280°C and a load of 1.2 kg, the melt flow index of the modified PA66 material was measured to be 8-20 g / 10 min.

4. The modified PA66 material according to claim 1 or 2, characterized in that, The number-average molecular weight of the amorphous polyarylene ether resin is 20 kDa-50 kDa; And / or, the compatibilizer is selected from one or more of polyetherimide or maleic anhydride grafted compatibilizers.

5. The modified PA66 material according to claim 1, characterized in that, The preparation method of the amorphous polyarylene ether resin includes: adding bisphenol monomer, dihalogen monomer, alkaline catalyst and dehydrating agent to a polymerization solvent, heating to the point where the dehydrating agent is refluxed and reacting for 1-4 h under nitrogen protection; after the dehydrating agent is removed, continuing to heat to 180-200℃ and reacting for 4-6 h to obtain the amorphous polyarylene ether resin.

6. The modified PA66 material according to claim 5, characterized in that, The bisphenol monomers are 4-(4-hydroxyphenyl)-2,3-diazanaphth-1-one and hydroquinone; And / or, the dihalogenated monomer is one or both of difluorobenzonitrile and 1,4-bis(4-fluorobenzoyl)benzene; And / or, the molar ratio of the bisphenol monomer to the dihalo monomer is (0.8-1.2):

1.

7. The modified PA66 material according to claim 5, characterized in that, The polymerization solvent is selected from one or both of sulfolane and N-methylpyrrolidone; And / or, the mass ratio of the polymerization solvent to the total mass of bisphenol monomer and dihalogen monomer is (1-2.5):1; And / or, the dehydrating agent is selected from one or both of toluene and xylene; And / or, the volume ratio of the dehydrating agent to the polymerization solvent is (1.5-2.5):1; And / or, the alkaline catalyst is selected from one or more of K2CO3, Na2CO3 and CaCO3; And / or, the molar ratio of the alkaline catalyst to the dihalogen monomer is (1.1-1.7):

1.

8. A process for the preparation of a modified PA66 material, characterized in that, The preparation method includes the following steps: a) After thoroughly drying PA66, amorphous polyarylene ether resin and compatibilizer at 80-120 ℃, they are mixed according to the formula ratio to obtain a mixture; b) The mixture is fed into an extruder for melt blending and granulation, wherein the extruder is heated to 250-300 ℃, and after cooling, it is granulated to obtain blended granules; c) The blended granules are extruded and drawn into fibers using an extruder, wherein the extruder barrel temperature is 250-300 ℃, and then drawn and cooled by a traction machine to obtain the modified PA66 material.

9. The preparation method according to claim 8, characterized in that, The extruder described in step b) and / or step c) is a twin-screw extruder; The screw speed of the extruder described in step b) and / or step c) is 80-200 rpm, and the feeder speed is 10-30 rpm; The cooling method described in step b) and / or step c) is air cooling; In step c), the speed of the tractor is 50-100 rpm.

10. The application of a modified PA66 material according to any one of claims 1-7 or a modified PA66 material prepared by the preparation method according to claim 8 or 9 in 3D printing.

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