Flame-retardant reinforced nylon material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and discloses a flame-retardant reinforced nylon material and a preparation method thereof. The flame-retardant reinforced nylon material comprises synergistically modified PA66, a small organic molecule function regulating agent, a flame retardant, a reinforcing filler, an antioxidant and a lubricant, wherein the synergistically modified PA66 is obtained by synergistically modifying phytic acid, diethylenetriaminepentaacetic acid and octa (3-aminopropyl) silsesquioxane through ionic association, chelating coordination and silicon oxygen cage structure confinement under the action of PA66 molecular chain terminal amino groups; the organic small molecule function regulating agent is 2, 6-diamino-anthraquinone. According to the invention, a synergetic modified PA66 structure is constructed and small organic molecules with a fused ring aromatic structure are introduced, so that the material can form a stable and compact carbon layer structure in the combustion process, thereby effectively improving the flame retardant property of the material and improving the mechanical property and structural stability of the material. The preparation method is simple and suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a flame-retardant reinforced nylon material and its preparation method. Background Technology

[0002] Nylon is an important class of engineering plastics. PA66, in particular, is widely used in automotive parts, electronic and electrical structural components, mechanical equipment parts, and industrial engineering materials due to its high crystallinity, excellent mechanical strength, wear resistance, heat resistance, and good dimensional stability. Especially in the electronics and automotive industries, PA66 is often used to manufacture connectors, wire harness sheaths, switch components, and structural supports. However, the PA66 molecular structure contains a large number of amide bonds, which are prone to thermal decomposition under high temperatures or flames, producing flammable gases and giving the material a certain degree of flammability. Furthermore, it is prone to dripping during combustion, increasing the risk of fire. Therefore, in many applications requiring high flame retardancy, PA66 materials must be modified for flame retardancy.

[0003] Currently, common flame-retardant nylon materials are typically achieved by adding phosphorus-based, nitrogen-based, or inorganic flame retardants, such as ammonium polyphosphate and phosphinate flame retardants, to PA66. While these flame retardants can improve the flame-retardant properties of the material to some extent, simply adding flame retardants often disrupts the continuous structure of the PA66 matrix, affecting the material's mechanical properties, toughness, and processing performance. Furthermore, the interfacial compatibility between the flame retardant and the nylon matrix is ​​poor, easily leading to uneven dispersion or insufficient interfacial bonding during processing and use, thus affecting the overall performance of the material.

[0004] To address these issues, some studies have enhanced interfacial bonding by adding coupling agents or surface-treating fillers. However, most existing technologies only address physical dispersion or simple surface modification, failing to construct stable synergistic structures at the molecular level. A good balance between flame retardant efficiency and mechanical properties remains elusive. Therefore, developing a flame-retardant reinforced nylon material capable of synergistically modifying the PA66 matrix structure and forming a stable structure at the molecular level, thereby simultaneously improving flame retardant properties, mechanical properties, and interfacial compatibility, holds significant research value and application prospects. Summary of the Invention

[0005] To overcome the problems of limited flame retardant efficiency, poor interfacial compatibility between the flame retardant and the nylon matrix, and easy degradation of mechanical properties in existing technologies that modify nylon materials with a single flame retardant, the present invention aims to provide a flame-retardant reinforced nylon material and its preparation method. This invention involves synergistic structural modification of PA66 by introducing phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane under the action of the terminal amino groups of the PA66 molecular chain. Through ion association, chelation coordination, and the confinement of the silica cage structure, PA66 is synergistically modified to construct a synergistically modified PA66 with a stable structure. Simultaneously, the organic small molecule functional regulator 2,6-diaminoanthraquinone is introduced into the system, working in conjunction with flame retardants, reinforcing fillers, antioxidants, and lubricants to obtain a flame-retardant reinforced nylon material. This invention, through the synergistic modification of PA66 by ion association, chelation coordination, and the confinement of the silica cage structure, significantly improves the flame retardant performance while maintaining good mechanical properties.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A flame-retardant reinforced nylon material, comprising the following raw materials in parts by weight: 60-85 parts of synergistically modified PA66; 1-8 parts of organic small molecule functional regulator; 8-20 parts of flame retardant; 5-25 parts of reinforcing filler; 0.1-1 parts of antioxidant; and 0.2-2 parts of lubricant. The synergistically modified PA66 is obtained by synergistic modification of PA66 by phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane under the action of the terminal amino group of the PA66 molecular chain, through ion association, chelate coordination, and confinement of the siloxane cage structure. The organic small molecule functional regulator is 2,6-diaminoanthraquinone.

[0008] Optionally, the synergistic modification of PA66 includes the following raw materials in parts by weight: 70-95 parts PA66; 0.5-4 parts phytic acid; 0.2-3 parts diethylenetriaminepentaacetic acid; and 0.5-5 parts octa(3-aminopropyl)silsesquioxane.

[0009] Optionally, the preparation method of synergistically modified PA66 includes the following steps:

[0010] (1) PA66 was mixed with phytic acid and reacted to obtain pre-modified PA66;

[0011] (2) Add diethylenetriaminepentaacetic acid to pre-modified PA66 to react and obtain secondary modified PA66;

[0012] (3) Add octa(3-aminopropyl)silsesquioxane to the secondary modified PA66 for reaction, then cool and dry to obtain synergistically modified PA66.

[0013] Optionally, the reaction conditions in step (1) are: stirring at 300-500 rpm for 20-40 min at 60-80°C.

[0014] Optionally, the reaction conditions in step (2) are: stirring at 300-500 rpm for 30-60 min at 80-100℃.

[0015] Optionally, the reaction conditions in step (3) are: stirring at 300-500 rpm for 40-90 min at 100-120 °C, followed by drying at 80-100 °C for 2-4 h.

[0016] Optionally, the flame retardant is a mixture of ammonium polyphosphate and aluminum diethylphosphinate in a mass ratio of (2-6):(1-3); the reinforcing filler is a mixture of glass fiber and talc in a mass ratio of (2-8):(1-4); the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of (1-3):(1-2); and the lubricant is a mixture of ethylene bis-stearamide and zinc stearate in a mass ratio of (1-4):(1-2).

[0017] Optionally, a method for preparing a flame-retardant reinforced nylon material includes the following steps:

[0018] S1, organic small molecule functional regulators, flame retardants, reinforcing fillers, antioxidants and lubricants are mixed according to the formula to obtain an additive mixture;

[0019] S2, the synergistically modified PA66 is mixed with the additive mixture and melt blended to obtain a blended melt;

[0020] S3 involves extruding, cooling, and granulating the blended melt to obtain flame-retardant reinforced nylon material.

[0021] Optionally, the reaction conditions for step S1 are: stirring and mixing at a speed of 300-600 rpm for 10-30 minutes at room temperature; the reaction conditions for step S2 are: melt blending using a twin-screw extruder at a temperature of 220-260°C, with a screw speed of 150-300 rpm.

[0022] Optionally, the reaction conditions for step S3 are as follows: the extrudate is cooled with water, pelletized, and dried at 80–100°C for 2–4 hours.

[0023] The beneficial effects of this invention are:

[0024] This invention modifies PA66 by introducing phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane into the terminal amino groups of the PA66 molecular chain. This modification involves ion association, chelation coordination, and siloxane cage confinement, creating a stable multi-site structure within the PA66 molecular chain. This allows the modified PA66 to more easily form a continuous and dense char layer during heating or combustion, effectively suppressing the release of combustible gases and reducing heat transfer. Simultaneously, the cage-like structure formed by octa(3-aminopropyl)silsesquioxane provides spatial confinement and structural support for the PA66 molecular chain, improving the material's thermal and structural stability. The multi-site interaction structure formed by phytic acid and diethylenetriaminepentaacetic acid enhances the interfacial bonding within the system. Furthermore, the introduction of 2,6-diaminoanthraquinone, with its fused-ring aromatic structure, further enhances the material's char-forming ability and promotes char layer densification. This significantly improves the flame-retardant efficiency of the material under the action of flame retardants, enabling the material to maintain high mechanical strength and structural stability while achieving excellent flame-retardant properties. Attached Figure Description

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Figure 1 The infrared spectra of PA66 and synergistically modified PA66 are compared.

[0027] Figure 2 This is a comparison chart of the flame retardant performance test results for samples with different formulation ratios. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0029] Example 1: This example verifies that when the components and process conditions are taken to their lower limits, the flame-retardant reinforced nylon material of the present invention can still form a stable synergistic modified structure and have basic flame-retardant properties.

[0030] S1, Preparation of Synergistically Modified PA66

[0031] 70 parts of PA66 were added to a high-speed mixer and preheated and stirred at 60°C. Then, 0.5 parts of phytic acid were added and stirred at 300 rpm for 20 min to allow ionic association between phytic acid and the terminal amino groups of PA66 molecular chains, resulting in pre-modified PA66. Subsequently, 0.2 parts of diethylenetriaminepentaacetic acid were added to the system and stirred at 300 rpm at 80°C for 30 min to allow diethylenetriaminepentaacetic acid to form a chelate coordination structure with phytic acid, resulting in secondary modified PA66. Then, 0.5 parts of octa(3-aminopropyl)silsesquioxane were added and stirred at 300 rpm at 100°C for 40 min. Finally, the mixture was dried at 80°C for 2 h to obtain synergistically modified PA66.

[0032] S2, blending modification

[0033] One part of 2,6-diaminoanthraquinone, eight parts of flame retardant, five parts of reinforcing filler, 0.1 parts of antioxidant, and 0.2 parts of lubricant were added to a mixer and mixed at 300 rpm for 10 minutes at room temperature to obtain an additive mixture. Then, 60 parts of synergistically modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 220°C with a screw speed of 150 rpm to obtain a blended melt.

[0034] S3, Granulation

[0035] The blended melt was extruded, cooled with water, and pelletized. Then it was dried at 80°C for 2 hours to obtain flame-retardant reinforced nylon material.

[0036] Example 2: This example verifies that when the average values ​​of each component and reaction condition are taken, the flame-retardant reinforced nylon material of the present invention can achieve good comprehensive performance between flame retardant properties and mechanical properties.

[0037] S1, Preparation of Synergistically Modified PA66

[0038] 82 parts of PA66 were added to a high-speed mixer and preheated and stirred at 70°C. Then, 2 parts of phytic acid were added and stirred at 400 rpm for 30 min to allow ionic association between phytic acid and the terminal amino groups of PA66 molecules, resulting in pre-modified PA66. Subsequently, 1.5 parts of diethylenetriaminepentaacetic acid were added and stirred at 400 rpm for 45 min at 90°C to form a chelated coordination structure, resulting in secondary modified PA66. Then, 2.5 parts of octa(3-aminopropyl)silsesquioxane were added and stirred at 400 rpm for 65 min at 110°C, followed by drying at 90°C for 3 h to obtain synergistically modified PA66. Figure 1 The infrared spectrum comparison shows that the unmodified PA66 has a wavelength of 3310 cm⁻¹. -1A distinct absorption peak appears at 1635 cm⁻¹, corresponding to the stretching vibration of the N–H in the amide group. -1 and 1540cm -1 The locations are respectively the amide I band (C=O stretching vibration) and the amide II band (N–H bending vibration), both at 2935 cm⁻¹. -1 and 2860cm -1 The presence of the –CH2– stretching vibration characteristic peak at 1225 cm⁻¹ indicates that the material possesses typical PA66 structural characteristics; compared to the unmodified material, the synergistically modified PA66 exhibits a higher peak at 1225 cm⁻¹. -1 and 1050cm -1 A distinct absorption peak appears at 1110 cm⁻¹, corresponding to the P=O and P–O structural vibrations, respectively, indicating that phytic acid has been successfully introduced into the PA66 system; simultaneously, an absorption peak appears at 1110 cm⁻¹. -1 and 810cm -1 The appearance of Si–O–Si and Si–C vibration peaks indicates that octa(3-aminopropyl)silsesquioxane participates in the reaction and is introduced into the material structure; the slight shift of amide I and amide II bands indicates that ion association and chelate coordination structures are formed in the system, thereby achieving synergistic modification of PA66;

[0039] S2, blending modification

[0040] Four parts of 2,6-diaminoanthraquinone, 14 parts of flame retardant, 15 parts of reinforcing filler, 0.5 parts of antioxidant, and 1 part of lubricant were added to a mixer and mixed at 450 rpm for 20 minutes at room temperature to obtain an additive mixture. Then, 72 parts of synergistically modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 240°C with a screw speed of 220 rpm to obtain a blended melt.

[0041] S3, Granulation

[0042] The blended melt was extruded, cooled with water, pelletized, and then dried at 90°C for 3 hours to obtain flame-retardant reinforced nylon material.

[0043] Example 3: This example verifies that when the upper limits of each component and reaction conditions are taken, the flame-retardant reinforced nylon material of the present invention can still maintain good processing performance and further improve the flame-retardant performance of the material.

[0044] S1, Preparation of Synergistically Modified PA66

[0045] 95 parts of PA66 were added to a high-speed mixer and preheated and stirred at 80°C. Then, 4 parts of phytic acid were added and stirred at 500 rpm for 40 min to allow ionic association between phytic acid and the terminal amino groups of PA66 molecules, resulting in pre-modified PA66. Subsequently, 3 parts of diethylenetriaminepentaacetic acid were added and stirred at 500 rpm for 60 min at 100°C to form a chelated coordination structure, resulting in secondary modified PA66. Then, 5 parts of octa(3-aminopropyl)silsesquioxane were added and stirred at 500 rpm for 90 min at 120°C, followed by drying at 100°C for 4 h to obtain synergistically modified PA66.

[0046] S2, blending modification

[0047] Eight parts of 2,6-diaminoanthraquinone, 20 parts of flame retardant, 25 parts of reinforcing filler, 1 part of antioxidant, and 2 parts of lubricant were added to a mixer and mixed at 600 rpm for 30 minutes at room temperature to obtain an additive mixture. Then, 85 parts of synergistically modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 260°C with a screw speed of 300 rpm to obtain a blended melt.

[0048] S3, Granulation

[0049] The blended melt was extruded, cooled with water, pelletized, and then dried at 100°C for 4 hours to obtain flame-retardant reinforced nylon material.

[0050] Comparative Example 1: This comparative example is used to verify that when PA66 is modified with only phytic acid without the introduction of diethylenetriaminepentaacetic acid and octa(3-aminopropyl)silsesquioxane, the material is difficult to form the ion association, chelate coordination and siloxane cage confined synergistic structure as in Example 2, thereby verifying the important role of synergistic modification in improving flame retardant and mechanical properties.

[0051] S1, Preparation of PA66 modified with phytic acid alone

[0052] 82 parts of PA66 were added to a high-speed mixer and preheated and stirred at 70°C. Then, 2 parts of phytic acid were added and stirred at 400 rpm for 30 min to allow phytic acid to undergo ionic association with the amino groups at the ends of the PA66 molecular chain. The mixture was then dried at 90°C for 3 h to obtain phytic acid-modified PA66.

[0053] S2, blending modification

[0054] Four parts of 2,6-diaminoanthraquinone, 14 parts of flame retardant, 15 parts of reinforcing filler, 0.5 parts of antioxidant, and 1 part of lubricant were added to a mixer and mixed at 450 rpm for 20 minutes at room temperature to obtain an additive mixture. Then, 72 parts of phytic acid-modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 240°C with a screw speed of 220 rpm to obtain a blended melt.

[0055] S3, Granulation

[0056] The blended melt was extruded, cooled with water, pelletized, and then dried at 90°C for 3 hours to obtain flame-retardant reinforced nylon material.

[0057] Comparative Example 2: This comparative example is used to verify that when PA66 is modified with only octa(3-aminopropyl)silsesquioxane without introducing phytic acid and diethylenetriaminepentaacetic acid, the material is difficult to form the multi-active site synergistic structure in Example 2, thereby verifying the role of synergistic modification in improving interface stability and overall performance.

[0058] Preparation of S1, octa(3-aminopropyl)silsesquioxane-modified PA66

[0059] 82 parts of PA66 were added to a high-speed mixer and preheated and stirred at 110°C. Then 2.5 parts of octa(3-aminopropyl)silsesquioxane were added and stirred at 400 rpm for 65 min. After that, the mixture was dried at 90°C for 3 h to obtain octa(3-aminopropyl)silsesquioxane-modified PA66.

[0060] S2, blending modification

[0061] Four parts of 2,6-diaminoanthraquinone, 14 parts of flame retardant, 15 parts of reinforcing filler, 0.5 parts of antioxidant, and 1 part of lubricant were added to a mixer and mixed at 450 rpm for 20 minutes at room temperature to obtain an additive mixture. Then, 72 parts of octa(3-aminopropyl)silsesquioxane-modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 240°C with a screw speed of 220 rpm to obtain a blended melt.

[0062] S3, Granulation

[0063] The blended melt was extruded, cooled with water, pelletized, and then dried at 90°C for 3 hours to obtain flame-retardant reinforced nylon material.

[0064] Comparative Example 3: This comparative example is used to verify that, under the condition of keeping the synergistically modified PA66 structure unchanged in Example 2, the char-forming promoting effect of the material is weakened after removing the organic small molecule functional regulator 2,6-diaminoanthraquinone, thereby verifying the effect of the organic small molecule on improving flame retardant performance and overall performance.

[0065] S1, Preparation of Synergistically Modified PA66

[0066] 82 parts of PA66 were added to a high-speed mixer and preheated and stirred at 70°C. Then, 2 parts of phytic acid were added and stirred at 400 rpm for 30 min to allow ionic association between phytic acid and the terminal amino groups of PA66 molecules, resulting in pre-modified PA66. Subsequently, 1.5 parts of diethylenetriaminepentaacetic acid were added and stirred at 400 rpm for 45 min at 90°C to form a chelated coordination structure, resulting in secondary modified PA66. Then, 2.5 parts of octa(3-aminopropyl)silsesquioxane were added and stirred at 400 rpm for 65 min at 110°C, followed by drying at 90°C for 3 h to obtain synergistically modified PA66.

[0067] S2, blending modification

[0068] 14 parts of flame retardant, 15 parts of reinforcing filler, 0.5 parts of antioxidant and 1 part of lubricant were added to a mixer and mixed at 450 rpm for 20 min at room temperature to obtain an additive mixture; then 72 parts of synergistically modified PA66 and the additive mixture were added to a twin-screw extruder and melt-blended at 240°C with a screw speed of 220 rpm to obtain a blended melt.

[0069] S3, Granulation

[0070] The blended melt was extruded, cooled with water, pelletized, and then dried at 90°C for 3 hours to obtain flame-retardant reinforced nylon material.

[0071] Performance testing:

[0072] 1. Flame retardant performance test method

[0073] The flame-retardant reinforced nylon materials prepared in the examples and comparative examples were injection molded into standard specimens using an injection molding machine. Before testing, the specimens were conditioned in an environment with a temperature of 23°C and a relative humidity of 50% for 48 hours. Then, the flame-retardant performance was tested according to the limiting oxygen index (LOI) test method. During the test, the specimens were placed vertically in a combustion device, and the oxygen concentration was gradually adjusted under a mixed oxygen and nitrogen atmosphere. The minimum oxygen volume fraction required to maintain continuous combustion of the specimen was recorded as the limiting oxygen index value of the material. The flame-retardant performance of the material was evaluated using this method.

[0074] 2. Tensile property test method

[0075] The flame-retardant reinforced nylon materials prepared in the examples and comparative examples were used to prepare standard tensile specimens. After conditioning in an environment with a temperature of 23°C and a relative humidity of 50% for 48 hours, the specimens were tested. Tensile properties were tested using an electronic universal testing machine. The specimens were fixed between tensile clamps and stretched at a constant tensile rate until fracture. The maximum stress and fracture condition of the specimens during the tensile process were recorded. Tensile strength and elongation at break were used as important indicators for evaluating the mechanical properties of the materials.

[0076] 3. Bending performance test method

[0077] The flame-retardant reinforced nylon materials prepared in the examples and comparative examples were used to prepare standard bending specimens. After being placed in an environment with a temperature of 23°C and a relative humidity of 50% for 48 hours, bending performance tests were conducted. The three-point bending test method was used, in which the specimen was placed horizontally between two supports of the bending test device, and a bending load was applied to the specimen under a constant loading rate. The maximum bending stress and deformation of the specimen during the bending process were recorded, and the bending strength and bending modulus were used as important indicators for evaluating the rigidity and load-bearing capacity of the material.

[0078] 4. Impact Performance Test Method

[0079] The flame-retardant reinforced nylon materials prepared in the examples and comparative examples were used to prepare standard impact specimens. After conditioning in an environment with a temperature of 23°C and a relative humidity of 50% for 48 hours, impact performance tests were conducted. Notched impact tests were performed on the specimens using a pendulum impact testing machine. An instantaneous impact load was applied to the specimens under specified impact energy conditions. The impact strength of the material was calculated by recording the impact energy consumed when the specimen fractured, thereby evaluating the toughness and impact resistance of the material.

[0080] Table 1. Performance test results of flame-retardant reinforced nylon materials

[0081] sample Limiting Oxygen Index (LOI, %) Tensile strength (MPa) Bending strength (MPa) Notched impact strength (kJ / m²) Example 1 30.5 83 118 6.9 Example 2 34.2 92 132 8.1 Example 3 32.6 88 126 7.5 Comparative Example 1 27.1 74 105 5.8 Comparative Example 2 26.5 72 101 5.6 Comparative Example 3 28.3 79 111 6.3

[0082] As shown in Table 1, the flame-retardant reinforced nylon materials prepared in the embodiments of the present invention and the comparative examples show significant differences in performance indicators such as limiting oxygen index, tensile strength, flexural strength, and notched impact strength. Overall, the performance of the embodiments of the present invention is significantly better than that of the comparative examples, with Example 2 showing the best performance in all performance indicators. This indicates that by synergistically modifying PA66 and introducing organic small molecule functional regulators, the flame-retardant and mechanical properties of the material can be significantly improved.

[0083] In terms of flame retardant performance Figure 2The limiting oxygen indices (LOIs) of Examples 1, 2, and 3 were 30.5%, 34.2%, and 32.6%, respectively, all significantly higher than those of Comparative Examples 1, 2, and 3 (27.1%, 26.5%, and 28.3%, respectively). Example 2 exhibited the highest LIO, indicating that the synergistic modification of PA66 by phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane, combined with the organic small molecule 2,6-diaminoanthraquinone, can promote the formation of a more stable and dense char layer structure during combustion, thereby effectively improving the flame retardant performance of the material. Comparative Examples 1 and 2, employing only a single modification method and failing to form a synergistic structure, showed significantly reduced flame retardant performance. Comparative Example 3, lacking the addition of an organic small molecule functional regulator, exhibited a weakened char-promoting effect, resulting in lower flame retardant performance compared to the Examples.

[0084] In terms of tensile properties, the tensile strength of the materials in the examples was higher than that of the comparative examples. Specifically, the tensile strength of Example 2 reached 92 MPa, while that of Comparative Examples 1 and 2 was only 74 MPa and 72 MPa, respectively. This indicates that the synergistic modification structure can enhance the interaction forces between PA66 molecular chains, improve the structural stability of the material, and thus enable the material to withstand greater stress. Simultaneously, the introduction of the small organic molecule 2,6-diaminoanthraquinone further enhances the structural stability of the system, allowing the material to maintain high mechanical strength while retaining flame retardant properties.

[0085] In terms of bending performance, the bending strength of the materials in the examples was significantly higher than that of the comparative examples, with Example 2 reaching a bending strength of 132 MPa. This is because octa(3-aminopropyl)silsesquioxane has a cage-like structure, which forms a spatial support structure within the material system, confining the PA66 molecular chains and thus improving the material's rigidity and structural stability. In contrast, the comparative examples, lacking a synergistic modified structure, exhibited poor internal structural stability, resulting in a significant decrease in bending strength.

[0086] In terms of impact performance, the notched impact strength of the materials in the examples was higher than that of the comparative examples, with Example 2 achieving a notched impact strength of 8.1 kJ / m², exhibiting better toughness. This indicates that the stable structure formed through multi-component synergistic modification can effectively disperse stress under external force, thereby improving the impact resistance of the material. In contrast, the comparative examples, due to the single modification method or lack of organic small molecule regulation, had a more fragile internal structure, resulting in lower impact performance.

[0087] In summary, by synergistically modifying PA66 with phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane, and introducing the organic small molecule functional regulator 2,6-diaminoanthraquinone, this invention can significantly improve the mechanical properties of the material while enhancing its flame retardant properties, thus achieving a synergistic improvement in both flame retardant and structural properties. The material achieves optimal overall performance when the median values ​​of each component and reaction condition are taken.

Claims

1. A flame-retardant reinforced nylon material, characterized in that, The flame-retardant reinforced nylon material comprises the following raw materials in parts by weight: 60-85 parts of synergistically modified PA66; 1-8 parts of organic small molecule functional regulator; 8-20 parts of flame retardant; 5-25 parts of reinforcing filler; 0.1-1 parts of antioxidant; and 0.2-2 parts of lubricant. The synergistically modified PA66 is obtained by synergistic modification of PA66 by phytic acid, diethylenetriaminepentaacetic acid, and octa(3-aminopropyl)silsesquioxane under the action of the terminal amino group of PA66 molecular chain through ion association, chelation coordination, and confinement of the siloxane cage structure. The organic small molecule functional regulator is 2,6-diaminoanthraquinone.

2. The flame-retardant reinforced nylon material according to claim 1, characterized in that, The synergistically modified PA66 comprises the following raw materials in parts by weight: 70-95 parts PA66; 0.5-4 parts phytic acid; 0.2-3 parts diethylenetriaminepentaacetic acid; and 0.5-5 parts octa(3-aminopropyl)silsesquioxane.

3. A flame-retardant reinforced nylon material according to claim 1 or 2, characterized in that, The preparation method of the synergistically modified PA66 includes the following steps: (1) PA66 was mixed with phytic acid and reacted to obtain pre-modified PA66; (2) Add diethylenetriaminepentaacetic acid to pre-modified PA66 to react and obtain secondary modified PA66; (3) Add octa(3-aminopropyl)silsesquioxane to the secondary modified PA66 for reaction, then cool and dry to obtain synergistically modified PA66.

4. The flame-retardant reinforced nylon material according to claim 3, characterized in that, The reaction conditions for step (1) are: stirring at 300-500 rpm for 20-40 minutes at 60-80°C.

5. The flame-retardant reinforced nylon material according to claim 3, characterized in that, The reaction conditions for step (2) are: stirring at 300-500 rpm for 30-60 minutes at 80-100℃.

6. The flame-retardant reinforced nylon material according to claim 3, characterized in that, The reaction conditions for step (3) are: stirring at 300-500 rpm for 40-90 min at 100-120℃, followed by drying at 80-100℃ for 2-4 h.

7. The flame-retardant reinforced nylon material according to claim 1, characterized in that, The flame retardant is a mixture of ammonium polyphosphate and aluminum diethylphosphonate in a mass ratio of (2-6):(1-3); the reinforcing filler is a mixture of glass fiber and talc in a mass ratio of (2-8):(1-4); the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of (1-3):(1-2); and the lubricant is a mixture of ethylene bis-stearamide and zinc stearate in a mass ratio of (1-4):(1-2).

8. A method for preparing a flame-retardant reinforced nylon material, characterized in that, The preparation method includes the following steps: S1, organic small molecule functional regulators, flame retardants, reinforcing fillers, antioxidants and lubricants are mixed according to the formula to obtain an additive mixture; S2, the synergistically modified PA66 is mixed with the additive mixture and melt blended to obtain a blended melt; S3 involves extruding, cooling, and granulating the blended melt to obtain flame-retardant reinforced nylon material.

9. The method for preparing a flame-retardant reinforced nylon material according to claim 8, characterized in that, The reaction conditions for step S1 are: stirring and mixing at 300-600 rpm for 10-30 minutes at room temperature; the reaction conditions for step S2 are: melt blending using a twin-screw extruder at 220-260℃ with a screw speed of 150-300 rpm.

10. The method for preparing a flame-retardant reinforced nylon material according to claim 8, characterized in that, The reaction conditions for step S3 are as follows: the extrudate is cooled with water, granulated, and dried at 80-100°C for 2-4 hours.

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