A yellowing-resistant halogen-free flame-retardant reinforced PPA composite material and preparation method thereof

Abstract

The invention discloses a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, which is composed of the following raw materials, by mass percentage: 50%-70% of high-temperature nylon PPA, 18% of hypophosphite halogen-free flame retardant, 18%-22% of glass fiber, 5-15% of amorphous non-crystalline nylon PA6I, 0.2%-0.5% of lactone type main antioxidant, 0.2%-0.5% of auxiliary antioxidant, and 0.3%-0.5% of lubricant; the lactone type main antioxidant is benzofuranone; the auxiliary antioxidant is a spirophosphite auxiliary antioxidant; the PA6I can destroy the regularity of the high-temperature nylon PPA molecular chain, reduce the crystallinity, and lower the melt temperature to avoid the degradation of the hypophosphite halogen-free flame retardant during processing. The low melting temperature of PA6I can further improve the material's fluidity and yellowing resistance. The lactone-type primary antioxidant used can effectively protect the color stability of the material during processing. The spirophosphite secondary antioxidant used has a high phosphorus content and can quench hydrogen peroxide during the material's self-oxidation process, avoiding yellowing or discoloration problems caused by oxidative degradation of the composite material.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a yellowing-resistant, halogen-free, flame-retardant and reinforced PPA composite material and a preparation method thereof. Background Art

[0002] Polyphthalamide (PPA for short) is a semi-aromatic polyamide, which is produced by a series of processes using isophthalic acid or terephthalic acid as the main synthetic raw materials. Compared with some fully aromatic polyamides, the process treatment of PPA is relatively simple, and it is easier to blow mold, injection mold and extrusion mold. In addition, the mechanical properties, thermal conductivity, heat resistance and chemical corrosion resistance of PPA are superior to those of aliphatic polyamides. After being modified with carbon fiber, glass fiber and other fillers, it can also achieve very good mechanical properties, and can maintain its performance for a long time and a wide temperature range. Because PPA has the advantages of high hardness, high strength, good chemical resistance and low cost, it has very common application scenarios in various industries such as automobiles, electrical appliances, and electronics. In specific application scenarios, such as electronic and electrical, automotive parts, industrial equipment, etc., when flame retardant properties are required, it is necessary to select modified PPA materials to ensure that they can have good flame retardant properties under high temperature or other special environments, thereby improving safety.

[0003] Halogen-free flame retardants refer to flame retardants that do not contain halogen elements such as chlorine and bromine. Traditional bromine and chlorine flame retardants will release toxic halogenated gases when exposed to fire, posing potential risks to the environment and health. Under the conditions of existing industrial technology, halogen-free flame retardants are mainly metal hydroxides and intumescent flame retardants. These two types of flame retardants do not emit smoke and corrosive gases when burned, and are called "green" flame retardants. Due to its environmental protection and safety, halogen-free flame retardants have been widely used in electronic appliances, building materials and other fields.

[0004] Chinese patent application number CN201110318262.9 discloses a high-strength antistatic thermal conductive PPA material, which includes the following components in weight percentage: polyphthalamide PPA 35-55%, carbon fiber 15-25%, graphite 5-10%, aluminum nitride 10-20%, flame retardant 10-15%, heat stabilizer 0.5-1.0%, nucleating agent 0.1-0.3%, the flame retardant used is a halogen-free flame retardant, and the halogen-free flame retardant is hypophosphite. The invention also provides a method for preparing the high-strength antistatic thermal conductive PPA material, which selects raw materials according to the above weight percentages, and mixes polyphthalamide, graphite, aluminum nitride, flame retardant, heat stabilizer and nucleating agent evenly to obtain a mixed raw material; the mixed raw material is placed in a twin-screw extruder and mixed with carbon fiber, and melt-extruded and granulated to obtain the high-strength antistatic thermal conductive PPA material. The extrusion temperature of the PPA material in the invention is as high as 310°C, and the decomposition of the hypophosphite halogen-free flame retardant starts from 300°C. The hypophosphite halogen-free flame retardant will degrade during the processing, which will eventually affect the stability of the mechanical properties of the finished product. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material and a preparation method thereof.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The invention discloses a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, which is composed of the following raw materials by mass percentage: 50%-70% of high-temperature nylon PPA, 18% of hypophosphite halogen-free flame retardant, 18%-22% of short glass fiber, 5-15% of amorphous non-crystalline nylon PA6I, 0.4%-1% of compound antioxidant and 0.3%-0.5% of lubricant.

[0008] Furthermore, the compound antioxidant is compounded by a lactone type main antioxidant and an auxiliary antioxidant, wherein, by mass percentage, the lactone type main antioxidant is 0.2%-0.5%, and the auxiliary antioxidant is 0.2%-0.5%.

[0009] Furthermore, the lactone type primary antioxidant is benzofuranone.

[0010] Furthermore, the secondary antioxidant is a spirophosphite secondary antioxidant.

[0011] Furthermore, the lubricant is PE wax.

[0012] A method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material comprises the following steps:

[0013] S1: Add high temperature nylon PPA, amorphous nylon PA6I, compound antioxidant and lubricant into a high-speed mixer according to a set ratio, stir evenly to obtain a premix, and set aside;

[0014] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

[0015] Furthermore, in step S1, the rotation speed of the high-speed mixer is 100 r / min.

[0016] Furthermore, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 200-315°C.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention provides a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, to which a certain amount of amorphous non-crystalline nylon PA6I is added, which can destroy the regularity of the high-temperature nylon PPA molecular chain, reduce the crystallinity, and reduce the temperature of the melt to avoid degradation of the hypophosphite halogen-free flame retardant during processing. The amorphous non-crystalline nylon PA6I itself has a low melting point, and can further improve the fluidity of the material and improve the material's yellowing resistance. At the same time, due to the improvement in fluidity, it is more conducive to the uniform dispersion of glass fiber in the composite material system, and it is easier to be infiltrated by the PPA high-temperature nylon resin, thereby improving the mechanical properties of the composite material.

[0019] 2. The compound antioxidant in the present invention is compounded by a lactone type main antioxidant and an auxiliary antioxidant, wherein, by mass percentage, the lactone type main antioxidant is 0.2%-0.5%, and the auxiliary antioxidant is 0.2%-0.5%. The combination of the lactone type main antioxidant and the auxiliary antioxidant can produce a synergistic effect and enhance the antioxidant performance. The lactone type main antioxidant can effectively delay the aging process of the polymer, while the auxiliary antioxidant can provide additional protection and extend the service life of the material. By compounding the lactone type main antioxidant and the auxiliary antioxidant, the material can be fully protected from multiple aspects and its antioxidant performance can be improved.

[0020] 3. The lactone type primary antioxidant in the present invention is benzofuranone, which has a resonant structure, and can push the anti-aging effect to another level at a very low concentration. The structure has no steric hindrance and will not produce steric hindrance. It can quickly react with a large number of carbon free radicals generated in the composite material. The removal of carbon free radicals can immediately terminate the self-oxidation reaction, thereby effectively inhibiting the self-oxidation cycle of the material. The lactone structure can also provide an active hydrogen atom to combine with the free radicals in the system, and generate a stable free radical at the same time, and further capture other free radicals, which can effectively protect the color stability of the material during processing.

[0021] 4. The auxiliary antioxidant in the present invention is a spirophosphite auxiliary antioxidant, which has a higher phosphorus content than other phosphite auxiliary antioxidants and can quench hydrogen peroxide during the material's self-oxidation process, thereby avoiding yellowing or discoloration problems caused by oxidative degradation of the composite material.

[0022] 5. The lubricant in the present invention is PE wax. Compared with other lubricants, PE wax can reduce the melt viscosity of the polyamide composite material, which is beneficial to improving the processing properties of the material such as injection molding and extrusion molding. PE wax has good heat resistance and can remain stable under high temperature conditions, which is beneficial to improving the thermal stability of the composite material.

[0023] 6. The present invention provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material. Since the hypophosphite-based halogen-free flame retardant has good fluidity and is relatively slippery, it is easy to accumulate on the feeding screw during the feeding process, causing difficulty in feeding. In step S2 of the present invention, the hypophosphite flame retardant and short glass fiber are simultaneously fed into a parallel twin-screw extruder from the side feeding port, so that the hypophosphite flame retardant is not easily accumulated on the feeding screw under the traction of the glass fiber, thereby stabilizing the extrusion granulation process.

[0024] 7. In step S1 of the present invention, the rotation speed of the high-speed mixer is 100 r / min. Slow stirring can reduce shear damage to the raw materials, which is beneficial to maintaining the stability of material properties.

[0025] 8. The screw length-to-diameter ratio of the parallel twin-screw extruder in the present invention is 48:1, which can provide sufficient extrusion pressure to make the extrusion process more sufficient and stable; the processing temperature adopted is 200-315°C, which can better control the melting state of the material while avoiding the decomposition of the hypophosphite halogen-free flame retardant, which is beneficial to improve the process stability of extrusion molding and ensure product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart of a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material. DETAILED DESCRIPTION

[0027] The following is in conjunction with the preferred embodiment and with reference to the attached Figure 1 , the present invention is further described. The endpoints and any values ​​of the ranges disclosed in the present 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 each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein; the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels; the experimental methods in the following examples, unless otherwise specified, are all conventional methods.

[0028] Example 1

[0029] This embodiment provides a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, which is composed of the following raw materials in terms of mass percentage:

[0030] Table 1 Components of yellowing-resistant halogen-free flame-retardant reinforced PPA composite materials

[0031] High temperature nylon PPA 51.3％ Hypophosphite halogen-free flame retardant 18％ Short glass fiber 20％ Amorphous Nylon PA6I 10％ Lactone type primary antioxidant 0.2％ Secondary antioxidant 0.2％ PE wax 0.3％

[0032] In this embodiment, a certain amount of amorphous non-crystalline nylon PA6I is added, which can destroy the regularity of the high-temperature nylon PPA molecular chain, reduce the crystallinity, and reduce the temperature of the melt to avoid degradation of the hypophosphite halogen-free flame retardant during processing. The amorphous non-crystalline nylon PA6I itself has a low melting point, which can further improve the fluidity of the material and improve the material's yellowing resistance. At the same time, due to the improvement in fluidity, it is more conducive to the uniform dispersion of glass fibers in the composite material system, and it is easier to be infiltrated by the PPA high-temperature nylon resin, thereby improving the mechanical properties of the composite material.

[0033] Among them, the lactone type main antioxidant is benzofuranone, which has a resonant structure and can push the anti-aging effect to another level at a very low concentration. The structure has no steric barrier and will not produce steric hindrance. It can quickly react with a large number of carbon free radicals generated in the composite material. The removal of carbon free radicals can immediately terminate the self-oxidation reaction, thereby effectively inhibiting the self-oxidation cycle of the material. The lactone structure can also provide an active hydrogen atom to combine with the free radicals in the system, and at the same time generate a stable free radical, and further capture other free radicals, which can effectively protect the color stability of the material during processing.

[0034] Among them, the auxiliary antioxidant is a spirophosphite auxiliary antioxidant, which has a higher phosphorus content than other phosphite auxiliary antioxidants and can quench hydrogen peroxide during the material self-oxidation process, thereby avoiding yellowing or discoloration problems caused by oxidative degradation of the composite material.

[0035] This embodiment also provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0036] S1: Add high-temperature nylon PPA, amorphous non-crystalline nylon PA6I, lactone type primary antioxidant, spirophosphite type secondary antioxidant, and PE wax into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0037] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

[0038] In the present embodiment, considering that the hypophosphite-based halogen-free flame retardant has good fluidity and is relatively slippery, it is easy to accumulate on the feeding screw during the feeding process, causing difficulty in feeding. In step S2 of the present embodiment, the hypophosphite flame retardant and short glass fiber are simultaneously fed into the parallel twin-screw extruder from the side feeding port, so that the hypophosphite flame retardant is not easily accumulated on the feeding screw under the traction of the glass fiber, thereby stabilizing the extrusion granulation process.

[0039] Wherein, in step S1, the rotation speed of the high-speed mixer is 100r / min, at which the shear damage to the raw materials can be reduced and the stability of the material properties can be maintained. The screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 300°C.

[0040] Example 2

[0041] This embodiment provides a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, which is different from Embodiment 1 in that the raw material composition ratio is different. The PPA composite material is composed of the following raw materials in terms of mass percentage:

[0042] Table 2 Components of yellowing-resistant halogen-free flame-retardant reinforced PPA composite materials

[0043] High temperature nylon PPA 70％ Hypophosphite halogen-free flame retardant 18％ Short glass fiber 22％ Amorphous Nylon PA6I 15％ Lactone type primary antioxidant 0.5％ Secondary antioxidant 0.5％ PE wax 0.5％

[0044] Wherein, the lactone type primary antioxidant is benzofuranone.

[0045] Wherein, the auxiliary antioxidant is a spirophosphite auxiliary antioxidant.

[0046] This embodiment also provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0047] S1: Add high-temperature nylon PPA, amorphous non-crystalline nylon PA6I, lactone type primary antioxidant, spirophosphite type secondary antioxidant, and PE wax into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0048] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

[0049] Wherein, in step S1, the rotation speed of the high-speed mixer is 100 r / min, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 315°C.

[0050] Example 3

[0051] This embodiment provides a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, which is different from Embodiment 1 in that the raw material composition ratio is different. The PPA composite material is composed of the following raw materials in terms of mass percentage:

[0052] Table 3 Components of yellowing-resistant halogen-free flame-retardant reinforced PPA composite materials

[0053] High temperature nylon PPA 60％ Hypophosphite halogen-free flame retardant 18％ Short glass fiber 18％ Amorphous Nylon PA6I 5％ Lactone type primary antioxidant 0.3％ Secondary antioxidant 0.3％ PE wax 0.4％

[0054] Wherein, the lactone type primary antioxidant is benzofuranone.

[0055] Wherein, the auxiliary antioxidant is a spirophosphite auxiliary antioxidant.

[0056] This embodiment also provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0057] S1: Add high-temperature nylon PPA, amorphous non-crystalline nylon PA6I, lactone type primary antioxidant, spirophosphite type secondary antioxidant, and PE wax into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0058] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

[0059] Wherein, in step S1, the rotation speed of the high-speed mixer is 100 r / min, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 200°C.

[0060] Comparative Example 1

[0061] The difference from Example 1 is that the raw material composition and proportion are different. The PPA composite material is composed of the following raw materials in terms of mass percentage:

[0062] Table 4 PPA composite material components

[0063] High temperature nylon PPA 61.3％ Hypophosphite halogen-free flame retardant 18％ Short glass fiber 20％ Nitrogen-containing hindered phenol lactone type primary antioxidant 0.2％ Phosphite auxiliary antioxidant 0.2％ PE wax 0.3％

[0064] This comparative example also provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0065] S1: Add high-temperature nylon PPA, nitrogen-containing hindered phenol lactone type primary antioxidant, phosphite type secondary antioxidant, and PE wax into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0066] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

[0067] Wherein, in step S1, the rotation speed of the high-speed mixer is 100 r / min, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 300°C.

[0068] Comparative Example 2

[0069] The difference from Comparative Example 1 is that: the feeding port of the hypophosphite flame retardant is different;

[0070] This comparative example provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0071] S1: Add high-temperature nylon PPA, nitrogen-containing hindered phenol lactone type primary antioxidant, phosphite secondary antioxidant, PE wax, and hypophosphite flame retardant into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0072] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and short glass fibers are fed into the parallel twin-screw extruder from a side feed port for melt mixing and extrusion granulation to obtain a halogen-free flame retardant reinforced PPA composite material.

[0073] Wherein, in step S1, the rotation speed of the high-speed mixer is 100 r / min, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 300°C.

[0074] Comparative Example 3

[0075] The difference from Comparative Example 1 is that: the feeding port of the hypophosphite flame retardant is different;

[0076] This comparative example provides a method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material, comprising the following steps:

[0077] S1: Add high-temperature nylon PPA, nitrogen-containing hindered phenol lactone type primary antioxidant, phosphite type secondary antioxidant, and PE wax into a high-speed mixer according to a set ratio, stir evenly, and obtain a premix for standby use;

[0078] S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, the hypophosphite flame retardant is fed into the parallel twin-screw extruder from a first side feed port, and the short glass fiber is fed into the parallel twin-screw extruder from a second side feed port, melt-mixed, and extruded into granules to obtain a halogen-free flame-retardant reinforced PPA composite material.

[0079] Wherein, in step S1, the rotation speed of the high-speed mixer is 100 r / min, the screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 300°C.

[0080] Implementation effect evaluation

[0081] The halogen-free flame-retardant reinforced PPA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were made into test specimens using an injection molding machine. The injection molding temperatures are shown in the following table:

[0082] Table 5 Injection molding process conditions of halogen-free flame retardant reinforced PPA samples

[0083]

[0084] The excellent effect achieved by the present invention is further illustrated by conducting specific tests on the halogen-free flame retardant reinforced PPA samples prepared in Examples 1-3 and Comparative Examples 1-3:

[0085] Impact performance test: Tested in accordance with ISO179-1 standard;

[0086] Tensile strength test: Tested in accordance with ISO527-2 standard;

[0087] Combustion performance test: Plastic combustion performance vertical method is tested according to IEC60695 and UL94 standards;

[0088] Bending strength and bending modulus test: tested in accordance with ISO178 standard;

[0089] Particle Appearance:

[0090] The appearance of the halogen-free flame retardant reinforced PPA samples prepared in Example 1-3 and Comparative Example 1-3 was observed, and it was found that the particles of Example 1-3 were overall white in appearance without any yellow spots, while the particle surface of Comparative Example 1-3 was yellowish, with yellow spots and temperature intolerance. This indicates that the present invention can improve the material's yellowing resistance and prevent the plastic melt from decomposing and yellowing by introducing amorphous non-crystalline nylon PA6I, lactone-type primary antioxidants and spirophosphite-type secondary antioxidants.

[0091] The extrusion process of Examples 1-3 and Comparative Examples 1-3 was observed, and it was found that under the traction of short glass fiber, the flame retardant feeding of the hypophosphite flame retardant of Examples 1-3 and Comparative Example 1 was normal, there was no powder accumulation at the side feeding port, and the extrusion granulation process was stable; while Comparative Example 2 was prone to particle and powder stratification, resulting in unstable feeding, large torque fluctuation of the main engine, and powder accumulation at the main feeding port, which required regular tapping by a vibrating air hammer to ensure stable feeding; the hypophosphite halogen-free flame retardant of Comparative Example 3 was easily accumulated at the first side feeding port, causing feeding difficulties, indicating that the preparation method of a yellowing-resistant halogen-free flame retardant reinforced PPA composite material provided by the present invention can solve the problem of easy accumulation of hypophosphite halogen-free flame retardant during the feeding process.

[0092] The rest of the test results are shown in the table below:

[0093] Table 6 Test results statistics

[0094]

[0095]

[0096] It can be seen from the above test results that the yellowing-resistant halogen-free flame-retardant reinforced PPA composite material provided by the present invention has excellent tensile strength, flexural strength, flexural modulus, flame retardant properties and impact strength, and has excellent fluidity at 325°C, which is more conducive to the dispersion of various components in the composite material system.

[0097] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A yellowing-resistant, halogen-free, flame-retardant and reinforced PPA composite material, characterized in that: The composition is composed of the following raw materials by mass percentage: 50%-70% of high temperature nylon PPA, 18% of hypophosphite halogen-free flame retardant, 18%-22% of short glass fiber, 5%-15% of amorphous non-crystalline nylon PA6I, 0.4%-1% of compound antioxidant and 0.3%-0.5% of lubricant; The compound antioxidant is compounded by a lactone type main antioxidant and an auxiliary antioxidant, wherein, by mass percentage, the lactone type main antioxidant is 0.2%-0.5%, and the auxiliary antioxidant is 0.2%-0.5%; The lactone type primary antioxidant is benzofuranone; The auxiliary antioxidant is a spirophosphite auxiliary antioxidant; A method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material comprises the following steps: S1: Add high temperature nylon PPA, amorphous nylon PA6I, compound antioxidant and lubricant into a high-speed mixer according to a set ratio, stir evenly to obtain a premix, and set aside; S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are simultaneously fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

2. The yellowing-resistant halogen-free flame-retardant reinforced PPA composite material according to claim 1, characterized in that: The lubricant is PE wax.

3. The method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material according to claim 1 or 2, characterized in that: The following steps are involved: S1: Add high temperature nylon PPA, amorphous nylon PA6I, compound antioxidant and lubricant into a high-speed mixer according to a set ratio, stir evenly to obtain a premix, and set aside; S2: The premix is ​​fed into a parallel twin-screw extruder from a main feed port, and the hypophosphite flame retardant and short glass fiber are simultaneously fed into the parallel twin-screw extruder from a side feed port for melt mixing, and extrusion granulation is performed to obtain a halogen-free flame retardant reinforced PPA composite material.

4. The method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material according to claim 3, characterized in that: In step S1, the rotation speed of the high-speed mixer is 100 r / min.

5. The method for preparing a yellowing-resistant halogen-free flame-retardant reinforced PPA composite material according to claim 3, characterized in that: The screw length-to-diameter ratio of the parallel twin-screw extruder is 48:1, and the processing temperature is 315°C.

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