High-strength long-glass-fiber-reinforced polyamide composite material and method for producing same

Abstract

The application discloses a high-strength long-glass-fiber reinforced polyamide composite material and a preparation method thereof, and belongs to the field of high polymer composite materials. The high-strength long-glass-fiber reinforced polyamide composite material comprises the following raw materials in parts by mass: polyamide resin 31-54.5 parts, high-modulus alkali-free glass fiber 30-60 parts, graphene oxide master batch 4-10 parts, compatilizer 1-3 parts, chain extender master batch 0.5-3 parts and processing aid 0.5-2 parts. The graphene oxide master batch is formed by cross-linking and attaching graphene oxide on polyamide resin PA6. The dispersibility of graphene oxide in the polyamide resin is solved, and under the action of the cross-linking agent, the nylon molecular chain is cross-linked and combined with the surface hydroxyl groups of the graphene oxide, the nylon molecules are effectively grafted on the graphene oxide sheet layer, the synergistic reinforcing effect of the graphene oxide and the glass fiber is achieved, the mechanical properties of the long-glass-fiber reinforced polyamide composite material are greatly improved, and the composite material is also endowed with good conductivity.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of high polymer composite materials, and particularly relates to a high-strength long-glass-fiber reinforced polyamide composite material and a preparation method thereof. BACKGROUND

[0002] Polyamide is one of commonly used engineering plastics due to its excellent flowability, heat resistance, chemical corrosion resistance, self-lubrication, high mechanical properties, good processing performance and many other advantages, and is widely applied in the fields of automobile, household appliance, electronic appliance, electric tool, medical equipment, building, etc. In order to further improve the mechanical properties, heat resistance, fatigue resistance, creep resistance and other properties in the application process, the polyamide is usually reinforced and filled with other reinforcing fillers such as glass fiber, and the material cost can also be reduced.

[0003] Due to the differences in processing methods and product characteristics, the personnel in this technical field distinguish long-glass-fiber reinforced nylon materials from short-glass-fiber reinforced nylon materials, and the long-glass-fiber reinforced polyamide material has higher strength, modulus, impact strength, fatigue resistance, creep resistance and other outstanding characteristics. In order to further improve the mechanical properties and other functionalities of the long-glass-fiber reinforced polyamide material, it needs to be synergistically reinforced and modified, and the graphene material can endow the long-glass-fiber reinforced polyamide material with better mechanical properties and conductivity and other functionalities due to its unique physical structure. However, the graphene is prone to agglomeration due to its microstructure, which causes uneven dispersion and cannot exert its potential value.

[0004] Therefore, a graphene dispersion problem is effectively solved, and the graphene is applied in the long-glass-fiber reinforced polyamide composite material to greatly improve the mechanical properties of the composite material and meet greater market demand. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a high-strength long-glass-fiber reinforced polyamide composite material and a preparation method thereof, which solve the problems in the prior art.

[0006] The purpose of the present application can be achieved by the following technical solutions.

[0007] A polyamide composite material comprises the following raw materials by mass:

[0008]

[0009] The graphene oxide master batch is formed by cross-linking and attaching the graphene oxide on the polyamide resin PA6.

[0010] Further, the polyamide resin is one or more of aliphatic polyamide resin PA6, PA46, PA56, PA66, PA11, PA12, PA610, PA1010, PA1012, PA612, PA1212.

[0011] Further, the high modulus alkali-free glass fiber has a filament diameter of 15-20 um and a linear density of 1200 tex, 2400 tex or 3600 tex.

[0012] Further, the chain extender master batch is an epoxy-based chain extender.

[0013] Further, the processing aid is at least one of an antioxidant, a weathering agent, a lubricant and a pigment.

[0014] Further, the preparation steps of the graphene oxide master batch are as follows:

[0015] Step 1: uniformly mix polyamide PA6 resin and graphene oxide at a ratio of 3 / 1, and place them in a ball mill, and perform ball milling process treatment on them under liquid nitrogen atmosphere to obtain a mixed powder;

[0016] Step 2: uniformly mix the mixed powder with a compatibilizer, a crosslinking agent, an antioxidant, a lubricant and a pigment at a ratio of 96:3:0.2:0.4:0.4 using a high-speed mixer, and place them in a twin-screw extruder for extrusion and granulation to obtain a graphene oxide master batch.

[0017] Further, the graphene oxide has a particle size D50≤5 um; and the crosslinking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide and tert-butyl peroxybenzoate.

[0018] Further, the compatibilizer is at least one of POE-g-MAH, SEBS-g-MAH and PP-g-MAH; the antioxidant is a mixture of a primary antioxidant and a secondary antioxidant at a ratio of 1 / 2, the primary antioxidant is a hindered phenolic antioxidant 1098, and the secondary antioxidant is a phosphite antioxidant 9228; and the lubricant is one or more of OP wax, polyester wax and ethylene-acrylic acid copolymer.

[0019] The above-mentioned method for preparing a polyamide composite material, characterized in that it comprises the following steps:

[0020] Polyamide resin, high modulus alkali-free glass fiber, graphene oxide master batch, compatibilizer and other processing aids are added into a stirring pot and mixed uniformly, then placed into a feeding port of a double screw extruder, and a chain extender master batch is added from a side feeding port; after the material is sheared and plasticized by the double screw, it is injected into an LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passes through the surface coating resin in the impregnation mold, and the polyamide composite material is obtained through water tank cooling, air drying and granulation.

[0021] The polyamide composite material is applied to the preparation of an automobile plastic part.

[0022] The polyamide composite material has the following beneficial effects:

[0023] 1. The graphene oxide master batch is prepared in a specific way, the polyamide resin is modified by blending, and a high-strength long glass fiber reinforced polyamide composite material is prepared, which not only solves the dispersibility problem of graphene oxide in the polyamide resin, but also, under the action of the crosslinking agent, the nylon molecular chain is crosslinked and combined with the hydroxyl groups on the surface of the graphene oxide, the nylon molecules are effectively grafted on the graphene oxide sheet, and the synergistic reinforcement of the graphene oxide and the glass fiber greatly improves the mechanical properties of the long glass fiber reinforced polyamide composite material, and also endows the composite material with good electrical conductivity.

[0024] 2. The chain extender is used in the preparation of the polyamide material, the PA6 molecules grafted on the surface of the graphene oxide are gradually expanded and the molecular weight is increased in the chain extension process, the entanglement between the chains is increased, the molecular chain is combined more closely with the glass fiber, and the graphene oxide is uniformly attached to the surface of the continuous glass fiber, thereby further effectively improving the mechanical properties of the composite material.

[0025] 3. The process route used in the patent to solve the dispersion problem of graphene oxide has obvious advantages compared with the preparation of GE / PA6 composite particles by in-situ polymerization in the prior art, the in-situ polymerization preparation of GE / PA6 composite particles needs to use a high-temperature reaction kettle, the reaction conditions are harsh, and the operation process is very complex; and the functionalized graphene oxide master batch can be prepared by using a double screw extruder, the operation process is simple, and the functionalized graphene oxide master batch has good practical application effect. DETAILED DESCRIPTION

[0026] The technical solutions of the present application will be described clearly and completely below with reference to the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] A high-strength long-glass-fiber reinforced polyamide composite material comprises the following raw materials in mass parts:

[0028]

[0029] The polyamide resin is one or more of aliphatic polyamide resins PA6, PA46, PA56, PA66, PA11, PA12, PA610, PA1010, PA1012, PA612, and PA1212.

[0030] The high-modulus alkali-free glass fiber has a filament diameter of 15-20 um and a linear density of 1200 tex, 2400 tex, or 3600 tex.

[0031] The chain extender master batch is an epoxy-based chain extender, specifically styrene-glycidyl methacrylate, and the matrix resin is PA6.

[0032] The processing aid is at least one of an antioxidant, a weathering agent, a lubricant, and a pigment.

[0033] The graphene oxide master batch is formed by cross-linking graphene to polyamide resin PA6; the specific steps are as follows: polyamide PA6 resin and graphene oxide are mixed in a ratio of 3 / 1, and are placed in a ball mill, and the two are subjected to ball milling process treatment under a liquid nitrogen atmosphere, and the mixed powder obtained after ball milling is mixed uniformly with a compatibilizer, a cross-linking agent, an antioxidant, a lubricant, and a pigment at a ratio of 96:3:0.2:0.4:0.4 using a high-speed mixer, and is placed in a twin-screw extruder for extrusion and granulation to obtain the graphene oxide master batch, and the processing temperatures of the extruder are 210℃, 230℃, 240℃, 240℃, 230℃, 230℃, 230℃, 220℃, 230℃, and 240℃, and the screw rotation speed is 400 r / min.

[0034] The particle size D50 of the graphene oxide is ≤5 um.

[0035] The compatibilizer is at least one of POE-g-MAH, SEBS-g-MAH, and PP-g-MAH.

[0036] The cross-linking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide, and tert-butyl peroxybenzoate.

[0037] The antioxidant is a mixture of a primary antioxidant and a secondary antioxidant compounded at a ratio of 1 / 2, the primary antioxidant is a hindered phenolic antioxidant 1098, and the secondary antioxidant is a phosphite antioxidant 9228.

[0038] The lubricant is one or more of OP wax, polyester wax, and ethylene-acrylic acid copolymer.

[0039] The preparation process of high-strength long glass fiber reinforced polyamide composite is illustrated below by the following examples, wherein the parts mentioned in the examples and comparative examples are all parts. Moreover, the raw reagents used in the examples and comparative examples of the present application are conventional purchased raw reagents, which are as follows:

[0040] Polyamide PA6: viscosity 2.4, brand BE3250, Jiangsu Hongsheng;

[0041] High modulus alkali-free glass fiber: continuous glass fiber with linear density 2400tex, brand SE4595, Owens Corning;

[0042] Compatibilizer: POE-g-MAH, brand CMG5805-L, Jia Yirong;

[0043] Graphene oxide: brand NO-C-068-1, Shanghai Nao Nano Technology Co., Ltd.;

[0044] Crosslinking agent, dicumyl peroxide (DCP), Akzo;

[0045] Chain extender masterbatch, brand REGRANYL MB-25, Xingbeida Chemical Industry;

[0046] Antioxidant 1098, BASF;

[0047] Antioxidant 9228, American Du Fort;

[0048] Lubricant, brand licowax op, Clariant;

[0049] Black masterbatch, brand BK-1032PAMB, Dongguan Zhi Chuang New Material Co., Ltd.

[0050] Example 1

[0051] The preparation process of high-strength long glass fiber reinforced polyamide composite is as follows:

[0052] S1, preparation of graphene oxide masterbatch; polyamide PA6 resin and graphene oxide are mixed uniformly at a ratio of 2 / 1, and are placed in a ball mill. In a liquid nitrogen atmosphere, the two are subjected to ball milling process treatment, and the mixed powder obtained after ball milling is mixed uniformly with compatibilizer, crosslinking agent, antioxidant, lubricant at a ratio of 96:3:0.2:0.4:0.4 using a high-speed mixer, and is placed in a twin-screw extruder for extrusion and granulation to obtain graphene oxide masterbatch; wherein the extruder processing temperature is 210℃, 230℃, 240℃, 240℃, 230℃, 230℃, 230℃, 220℃, 230℃, 240℃, and the screw rotation speed is 400r / min.

[0053] S2, 54.5 parts of polyamide resin, 30 parts of high modulus alkali-free glass fiber, 10 parts of graphene oxide master batch, 1 part of compatibilizer, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 9228, 0.2 parts of lubricant and 0.8 parts of black master batch were added into a stirring pot and mixed uniformly, then placed into the discharge port of a twin-screw extruder, 3 parts of chain extender master batch was added from the side feeding port, the material was sheared and plasticized by the twin-screw, then injected into the LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passed through the surface coating resin in the impregnation mold, and finally the high strength long glass fiber reinforced polyamide composite material was obtained after water tank cooling, air drying and granulation. The impregnation mold temperature was 300°C; the temperature of the twin-screw extruder from zone 1 to zone 10 was 210°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 290°C, 290°C, and the screw speed was 400 r / min.

[0054] Example 2

[0055] The preparation process of the high strength long glass fiber reinforced polyamide composite material is as follows:

[0056] S1, graphene oxide master batch preparation; polyamide PA6 resin and graphene oxide were mixed uniformly at a ratio of 2 / 1, and were placed in a ball mill, and were subjected to ball milling process treatment under liquid nitrogen atmosphere, and the mixed powder obtained after ball milling was mixed uniformly with compatibilizer, crosslinking agent, antioxidant, lubricant at a ratio of 96:3:0.2:0.4:0.4 using a high-speed mixer, and was placed in a twin-screw extruder for extrusion and granulation to obtain a graphene oxide master batch; wherein the extruder processing temperature was 210°C, 230°C, 240°C, 240°C, 230°C, 230°C, 230°C, 220°C, 230°C, 240°C, and the screw speed was 400 r / min.

[0057] S2, 54.5 parts of polyamide resin, 30 parts of high modulus alkali-free glass fiber, 10 parts of graphene oxide master batch, 1 part of compatibilizer, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 9228, 0.2 parts of lubricant and 0.8 parts of black master batch were added into a stirring pot and mixed uniformly, then placed into the discharge port of a twin-screw extruder, 3 parts of chain extender master batch was added from the side feeding port, the material was sheared and plasticized by the twin-screw, then injected into the LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passed through the surface coating resin in the impregnation mold, and finally the high strength long glass fiber reinforced polyamide composite material was obtained after water tank cooling, air drying and granulation. The impregnation mold temperature was 300°C; the temperature of the twin-screw extruder from zone 1 to zone 10 was 210°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 290°C, 290°C, and the screw speed was 400 r / min.

[0058] Example 3

[0059] The preparation process of the high-strength long-glass-fiber reinforced polyamide composite material is as follows:

[0060] S1, graphene oxide master batch preparation; take polyamide PA6 resin and graphene oxide in a ratio of 2 / 1, mix uniformly, and place in a ball mill. Under the atmosphere of liquid nitrogen, the two are subjected to ball milling process treatment. The mixed powder obtained after ball milling is mixed uniformly with a compatibilizer, a crosslinking agent, an antioxidant, a lubricant, and a high-speed mixer at a ratio of 96:3:0.2:0.4:0.4, and is placed in a twin-screw extruder for extrusion and granulation to obtain a graphene oxide master batch. The processing temperatures of the extruder are 210℃, 230℃, 240℃, 240℃, 230℃, 230℃, 230℃, 220℃, 230℃, and 240℃, respectively, and the screw speed is 400 r / min.

[0061] S2, 38 parts of polyamide resin, 50 parts of high-modulus alkali-free glass fiber, 6 parts of graphene oxide master batch, 3 parts of compatibilizer, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 9228, 0.5 parts of lubricant, and 1 part of black masterbatch are added to a stirring pot and mixed uniformly. Then, it is placed in the discharge port of a twin-screw extruder, and 1 part of a chain extender masterbatch is added from the side feeding port. After the material is subjected to shearing and plasticizing by the twin-screw, it is injected into an LFT-G impregnation mold at a constant conveying rate. The high-modulus alkali-free glass fiber passes through the surface of the resin in the impregnation mold, and is finally obtained after being cooled in a water tank, air-dried, and cut into particles. The temperature of the impregnation mold is 300℃, and the temperature of the twin-screw extruder from zone 1 to zone 10 is 210℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 290℃, and 290℃, respectively, and the screw speed is 400 r / min.

[0062] Example 4

[0063] The preparation process of the high-strength long-glass-fiber reinforced polyamide composite material is as follows:

[0064] S1, graphene oxide master batch preparation; take polyamide PA6 resin and graphene oxide in a ratio of 2 / 1, mix uniformly, and place in a ball mill. Under the atmosphere of liquid nitrogen, the two are subjected to ball milling process treatment. The mixed powder obtained after ball milling is mixed uniformly with a compatibilizer, a crosslinking agent, an antioxidant, a lubricant, and a high-speed mixer at a ratio of 96:3:0.2:0.4:0.4, and is placed in a twin-screw extruder for extrusion and granulation to obtain a graphene oxide master batch. The processing temperatures of the extruder are 210℃, 230℃, 240℃, 240℃, 230℃, 230℃, 230℃, 220℃, 230℃, and 240℃, respectively, and the screw speed is 400 r / min.

[0065] S2, 31 parts of polyamide resin, 60 parts of high modulus alkali-free glass fiber, 4 parts of graphene oxide masterbatch, 3 parts of compatibilizer, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 9228, 0.2 parts of lubricant and 0.8 parts of black masterbatch were added into a stirring pot and uniformly mixed, and then placed into a feeding port of a twin-screw extruder, 0.5 parts of chain extender masterbatch was added from a side feeding port, and the material was sheared and plasticized by the twin-screw, and then injected into an LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passed through the surface coating resin in the impregnation mold, and finally the high strength long glass fiber reinforced polyamide composite material was obtained after water tank cooling, air drying and granulation. The temperature of the impregnation mold was 300°C; the temperature of the twin-screw extruder from zone 1 to zone 10 was 210°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 290°C, 290°C, and the screw speed was 400 r / min.

[0066] Comparative Example 1

[0067] The preparation process of the polyamide composite material is as follows:

[0068] The preparation process of the polyamide composite material is as follows:

[0069] Comparative Example 2

[0070] The preparation process of the polyamide composite material is as follows:

[0071] S1, the graphene oxide masterbatch was prepared according to the step S1 of Example 1;

[0072] S2, 57.5 parts of polyamide resin, 30 parts of high modulus alkali-free glass fiber, 10 parts of graphene oxide master batch, 1 part of compatibilizer, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 9228, 0.2 parts of lubricant and 0.8 parts of color master are added to a stirring pot and mixed uniformly, then placed in the discharge port of a double screw extruder, the material is sheared and plasticized by the double screw, and then injected into the LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passes through the surface of the resin in the impregnation mold, and finally the high strength long glass fiber reinforced polyamide composite material is obtained after water cooling, air drying and granulation. The temperature of the impregnation mold is 300°C; the temperature of the double screw extruder from zone 1 to zone 10 is 210°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 290°C, 290°C, and the screw speed is 400 r / min.

[0073] The amounts of raw materials used in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1 below:

[0074] Table 1 Amounts of raw materials used in Examples 1-4 and Comparative Examples 1-2

[0075] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 PA6 54.5 47.5 38 31 62 57.5 Continuous glass fiber 30 40 50 60 30 30 Graphene oxide masterbatch 10 8 6 4 / 10 Graphene oxide / / / / 2.5 / Compatibilizer 1 2 3 3 1 1 Chain extender masterbatch 3 2 1 0.5 3 / Antioxidant 1098 0.2 0.2 0.2 0.2 0.2 0.2 Antioxidant 9228 0.3 0.3 0.3 0.3 0.3 0.3 Lubricant 0.2 / 0.5 0.2 0.2 0.2 Color masterbatch 0.8 / 1 0.8 0.8 0.8

[0076] The materials prepared in Examples 1-4 and Comparative Examples 1-2 were tested for performance, and the test standards and test data are shown in Table 2 below:

[0077] Table 2 Performance test results of materials prepared in Examples 1-4 and Comparative Examples 1-2

[0078]

[0079]

[0080] The graphene oxide master batch prepared in Examples 1-4 was used to blend modify the polyamide resin to prepare a high strength long glass fiber reinforced polyamide composite material. The polyamide PA6 resin and graphene oxide were mixed uniformly in a certain proportion, then placed in a ball mill, and treated by ball milling under liquid nitrogen atmosphere to obtain a mixed powder. The mixed powder, compatibilizer, crosslinking agent, antioxidant and lubricant were mixed uniformly at high speed and then extruded and granulated in a double screw extruder to obtain the graphene oxide master batch. The prepared graphene oxide master batch not only solves the dispersion problem of graphene oxide, but also under the action of the crosslinking agent, the nylon molecular chain and the hydroxyl group on the surface of graphene are crosslinked and combined, the nylon molecules are effectively grafted on the graphene layer, and the synergistic reinforcement effect of graphene and glass fiber greatly improves the mechanical properties of the long glass fiber reinforced polyamide composite material, and also endows the composite material with good electrical conductivity.

[0081] It can be seen from the results of Table 2 that the introduction of graphene oxide significantly improves the mechanical properties of long glass fiber reinforced polyamide composites and effectively reduces the resistance and improves the electrical conductivity. Referring to Example 1 and Comparative Example 1, it can be clearly observed that when graphene oxide is directly added to the composite system, the mechanical properties of the prepared composite generally show a significant decline, and the volume resistivity is significantly higher, which is due to the fact that graphene oxide cannot be fully dispersed in the resin system, thereby failing to exert its benefits. Referring to Example 1 and Comparative Example 2, it can be observed that when no chain extender masterbatch is added to the system, the mechanical properties of the obtained composite are low, which is due to the use of chain extender. On the one hand, it can react with the functional groups on the polymer chain to expand the molecular chain, increase the molecular weight, and increase the entanglement between the chains, making it difficult for the molecular chain to slip, thereby improving the mechanical properties. On the other hand, the PA6 molecules grafted on the surface of graphene oxide can be more closely combined with glass fibers during the chain extension process, and graphene oxide is uniformly attached to the surface of the continuous glass fiber, thereby further effectively improving the mechanical properties of the composite.

[0082] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0083] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A polyamide composite, characterized in that, The following quality parts of raw materials are included: Polyamide resin 31~54.5 parts; High modulus alkali-free glass fiber 30~60 parts; Graphene oxide masterbatch 4-10 parts; Compatibilizer 1~3 parts; Chain extender masterbatch 0.5~3 parts; Processing aid 0.5~2 parts; The graphene oxide masterbatch is formed by cross-linking graphene oxide attached to polyamide resin PA6; The preparation steps of the graphene oxide masterbatch are as follows: Step 1: Take polyamide PA6 resin and graphene oxide with a ratio of 3 / 1, mix uniformly, and place in a ball mill. Under the atmosphere of liquid nitrogen, the two are subjected to ball milling process treatment to obtain a mixed powder; Step 2: Mix the mixed powder with compatibilizer, crosslinking agent, antioxidant, lubricant at a ratio of 96:3:0.2:0.4:0.4 using a high-speed mixer, and place in a twin-screw extruder for extrusion and granulation to obtain the graphene oxide masterbatch; The particle size D50 of the graphene oxide is ≤5um; the crosslinking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide, and tert-butyl peroxybenzoate; The chain extender masterbatch is an epoxy chain extender.

2. A polyamide composite according to claim 1, characterized in that The polyamide resin is one or more of aliphatic polyamide resins PA6, PA46, PA56, PA66, PA11, PA12, PA610, PA1010, PA1012, PA612, and PA1212.

3. A polyamide composite according to claim 1, characterized in that The single filament diameter of the high modulus alkali-free glass fiber is 15~20um, and the linear density is 1200tex, 2400tex or 3600tex.

4. A polyamide composite according to claim 1, characterized in that The processing aid is at least one of an antioxidant, a lubricant, and a pigment.

5. A polyamide composite according to claim 4, characterized in that The compatibilizer is at least one of POE-g-MAH, SEBS-g-MAH, and PP-g-MAH; the antioxidant is a mixture of main antioxidant and auxiliary antioxidant compounded at a ratio of 1 / 2, the main antioxidant is hindered phenolic antioxidant 1098, and the auxiliary antioxidant is phosphite antioxidant 9228; the lubricant is one or more of OP wax, polyester wax, and ethylene-acrylic acid copolymer.

6. A process for the production of a polyamide composite according to any one of claims 1 to 5, characterized in that The following steps are included: Add polyamide resin, graphene oxide masterbatch, compatibilizer, and processing aid to a stirring pot and mix uniformly, then place in the discharge port of a twin-screw extruder, add chain extender masterbatch from the side feed port, and after the material is sheared and plasticized by the twin-screw, inject it into the LFT-G impregnation mold at a constant conveying rate, the high modulus alkali-free glass fiber passes through the surface of the resin in the impregnation mold, and after cooling in a water tank, air drying, and granulation, a polyamide composite material is obtained.

7. Use of the polyamide composite material of any one of claims 1-5 in the preparation of an automobile plastic part.

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