Semi-aromatic polyamide composite material as well as preparation method and application thereof

Abstract

The invention discloses a semi-aromatic polyamide composite material which comprises the following components in parts by weight: 79-101 parts of semi-aromatic polyamide; 5 to 30 parts of a maleic anhydride grafted toughening agent; 4-8 parts of an amine electrolyte-resistant modifier; and 2-5 parts of an ethylene-vinyl alcohol copolymer. The semi-aromatic polyamide composite material disclosed by the invention has the advantages of good cooling liquid resistance and electrolyte resistance, has the elongation at break of more than 150%, and is suitable for preparing a liquid cooling pipeline of a new energy vehicle.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a semi-aromatic polyamide composite material and a preparation method and application thereof. Background Art

[0002] The fundamental changes in the power systems of new energy vehicles, especially pure electric vehicles, are reshaping the thermal management system architecture of vehicles. Compared with traditional fuel vehicles, electric vehicles need to further improve thermal management efficiency. The cooling system of new energy vehicles can be divided into air cooling, liquid cooling and phase change materials according to the cooling medium. Liquid cooling is currently the main cooling method for new energy vehicles, including water cooling and oil cooling. As an important component of new energy vehicles, the coolant pipeline needs to meet multiple requirements such as hydrolysis resistance, oil resistance, high temperature resistance, and lightweight. In particular, when the battery leaks, the coolant pipeline needs to have electrolyte resistance, which can effectively suppress battery short circuits and fires caused by electrolyte leakage.

[0003] In the prior art, rubber hoses are rarely used due to their poor environmental adaptability or low cooling efficiency. For example, silicone hoses have low cooling efficiency, high weight, and are easy to age. Nylon tubes and other materials have gradually become the main materials used for coolant pipelines due to their light weight and simple processing technology. The nylons used in coolant pipelines mainly include aliphatic and aromatic nylons. Aliphatic nylons are represented by PA11, PA12, and PA612, and aromatic nylons are represented by PA9T and PA11T. Nylon plastic pipes can be used in the motor compartment, chassis, and battery pack. According to the different requirements of temperature, pressure, and assembly at different locations, select nylon materials and structural types with corresponding temperature resistance grades. However, these aliphatic nylons are not tolerant to coolants and electrolytes and often need to be prepared into multi-layer structures. For example, PA11 and PA12 materials need to be prepared into three-layer or five-layer pipes with barrier materials such as EVOH, ETFE, and EFEP to meet the requirements of long-term use. PA612 can only be used as a cost-reduction solution for PA11 and PA12 because of its poorer resistance to hydrolysis and alcoholysis, and is currently less used.

[0004] At the same time, for the cooling pipes used in new energy electric vehicles, the elongation at break is a key indicator of the pipe material, and is closely related to the elongation test, burst test, and dynamic fatigue test performance of the pipe after molding. It is generally believed in the industry that the elongation at break of the material > 150% can meet the requirements of the elongation test, burst test, and dynamic fatigue test of the pipe and prepare qualified pipes; and when the elongation at break of the material is < 20%, the service life of the material has reached its limit. Therefore, by testing the initial elongation at break and after resistance to coolant, it can be shown whether the polyamide composition is suitable for the pipe.

[0005] Patent CN118063957A discloses a flexible hydrolysis-resistant extruded polyamide material, which mainly includes 20-52% polyamide resin, 20-50% polyphenylene ether resin, 3-7% compatibilizer, 8-14% toughening agent, 10-14% composite plasticizer, 0.3-0.6% antioxidant and 0.4-0.7% lubricant. The patent mainly uses aliphatic polyamide PA6, PA612 and other resin matrices, which have poor electrolyte resistance. Summary of the invention

[0006] The object of the present invention is to provide a semi-aromatic polyamide composite material with good resistance to coolant and electrolyte and high elongation at break, and a preparation method and application thereof.

[0007] The present invention is achieved through the following technical solutions: A semi-aromatic polyamide composite material, characterized in that it comprises the following components in parts by weight: 79-101 parts of semi-aromatic polyamide; 5-30 parts of maleic anhydride grafted toughening agent; 4-8 parts of amine electrolyte resistance modifier; 2-5 parts of ethylene-vinyl alcohol copolymer; The semi-aromatic polyamide is derived from the following units, measured in mole percentage: The diacid units are derived from terephthalic acid and a straight-chain diacid containing at least 10 carbon atoms, wherein terephthalic acid accounts for 55-85 mol% of the molar content of the diacid units, and the straight-chain diacid containing at least 10 carbon atoms is selected from at least one of 1,10-decanedioic acid, 1,12-dodecanedioic acid, and 1,18-octadecandioic acid, wherein 1,10-decanedioic acid accounts for 50-100 mol% of the total molar percentage content of the straight-chain diacid containing at least 10 carbon atoms; The diamine units are derived from 1,10-decanediamine and 1,12-dodecanediamine, wherein 1,10-decanediamine accounts for 50-100 mol% of the total molar percentage content of the diamine units; The amine electrolyte-resistant modifier is selected from at least one of N-ethyl-p-toluenesulfonamide, dendritic polyamidoamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), N,N'-di(2,6-diisopropylphenyl)carbodiimide and diethyltoluenediamine.

[0008] In the semi-aromatic polyamide composite material of the present invention, the content of the semi-aromatic polyamide can be 79 parts, 81 parts, 83 parts, 85 parts, 87 parts, 89 parts, 91 parts, 93 parts, 95 parts, 97 parts, 99 parts, 101 parts; the content of the maleic anhydride grafted toughening agent can be 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, 30 parts, etc.; the content of the amine electrolyte resistance modifier can be 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, etc.; the content of the ethylene-vinyl alcohol copolymer can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0009] The molar content of ethylene in the ethylene-vinyl alcohol copolymer of the present invention may be in the range of 20-45 mol%.

[0010] In the semi-aromatic polyamide composite material of the present invention, the semi-aromatic polyamide accounts for no less than 60wt% of the total weight percentage.

[0011] Preferably, terephthalic acid accounts for 65-75 mol% of the molar content of diacid units.

[0012] Preferably, the amine electrolyte resistance modifier is selected from at least one of N-ethyl p-toluenesulfonamide and dendritic polyamidoamine.

[0013] More preferably, the amine electrolyte resistance modifier is selected from dendritic polyamidoamine.

[0014] The maleic anhydride grafted toughening agent is selected from at least one of maleic anhydride grafted POE, maleic anhydride grafted SEBS and maleic anhydride grafted EPDM.

[0015] In the maleic anhydride grafted toughening agent, the grafting rate of maleic anhydride is 1-5wt%.

[0016] Preferably, in the maleic anhydride grafted toughening agent, the grafting rate of maleic anhydride is 2-3wt%.

[0017] The maleic anhydride grafted toughening agent can be a commercially available product or can be obtained by self-production, and the self-production method includes but is not limited to: mixing the initiator (dicumyl peroxide, dibenzoyl peroxide), the unmodified toughening agent, and maleic anhydride according to the designed proportion, and mixing them in a mixer at 180-220°C to obtain the obtained product.

[0018] The test method for the content of maleic anhydride can be: acid-base titration. The specific operation method is: put the copolymer into xylene and heat it under reflux to dissolve, after cooling, add a certain amount of 0.05mol / L potassium hydroxide-ethanol solution, and then heat it under reflux for 8h, use 0.1% phenolphthalein solution as an indicator, and titrate to the end point with 0.05mol / L HCl-isopropanol solution while it is hot. The weight content G is calculated using the following formula: G = (N1 × Vl - N2 × V2) × M ÷ w ÷ 10 Where: N1: KOH-ethanol solution equivalent concentration, N; V1: volume of KOH-ethanol solution, ml; N2: HCl-isopropanol solution equivalent concentration, N; V2: volume of HCl-isopropanol solution, ml; M: equivalent mass of maleic anhydride, g; w: weight of the dried sample after extraction, g.

[0019] The relative viscosity of the semi-aromatic polyamide is in the range of 2.4-3.2. The test method is: refer to GB12006.1-89, polyamide viscosity determination method; the specific test method is: measure the relative viscosity ηr of polyamide with a concentration of 0.25 g / dl in 98% concentrated sulfuric acid at 25±0.01°C.

[0020] The semi-aromatic polyamide of the present invention can be a commercially available product or can be obtained by self-production. The self-production method includes but is not limited to: adding reaction monomers, benzoic acid, sodium hypophosphite and deionized water into a pressure autoclave; the amount of benzoic acid substance is 1-3% of the total amount of diamine and diacid substances, the weight of sodium hypophosphite is 0.05-0.15% of the total weight of other materials except deionized water, and the weight of deionized water is 20-40% of the total weight of the materials; vacuuming and filling with high-purity nitrogen as a protective gas, heating to 190-210° C. within 1.5-2.5 hours under stirring, stirring the reaction mixture at 190-210° C. for 0.5-1.5 hours, and then raising the temperature of the reactants to 260-280° C. under stirring; reacting at a temperature of 260-280° C. and a constant pressure of 3.0-3.4 MPa for 1-3 hours, keeping the pressure constant by removing the formed water, and then gradually reducing the pressure to normal pressure, discharging the material after the reaction is completed to obtain a polyamide resin. Whether to add 0-3 parts of auxiliary agent can be selected according to actual needs, and the auxiliary agent is selected from at least one of UV stabilizer, heat stabilizer and pigment.

[0021] The melting point range of the semi-aromatic polyamide of the present invention is 250-290° C. The test is performed using a differential scanning calorimeter (DSC) in accordance with ISO 11357-3-2018 standard.

[0022] The preparation method of the semi-aromatic polyamide composite material of the present invention comprises the following steps: mixing the components uniformly according to the proportion, and extruding and granulating through a twin-screw extruder to obtain the semi-aromatic polyamide composite material.

[0023] The semi-aromatic polyamide composite material of the invention is used for preparing liquid cooling pipelines.

[0024] The present invention has the following beneficial effects: First, the present invention copolymerizes diacid monomers with aromatic benzene rings with diacids and diamine monomers with long carbon chains, and controls the molar ratio to adjust the ratio of diamine and diacid units, thereby obtaining a long carbon chain semi-aromatic polyamide with a specific structure. The long carbon chain structure in the molecular chain is used to provide the resin with high toughness and easy processing characteristics; at the same time, the benzene ring structure in the molecular chain is used to provide the material with excellent chemical resistance.

[0025] Second, in the present invention, by using an amine electrolyte-resistant modifier, it is found that the toughness and chemical resistance of the composite material are further increased. This is because the amine electrolyte-resistant modifier can, on the one hand, combine with the amino groups on the polyamide molecular chain to form hydrogen bonds, thereby reducing the interaction between the molecular chains, improving the mobility of the molecular chains, improving the flexibility and thus the toughness of the material; on the other hand, the amine electrolyte-resistant modifier can combine with the acidic substances in the electrolyte immersed in the material, thereby reducing the acid decomposition caused by the carboxyl group attacking the polyamide molecular chain, so that the electrolyte resistance of the material is improved.

[0026] Third, the present invention increases the penetration path of the electrolyte by adding ethylene-vinyl alcohol copolymer, utilizing the good chemical resistance of ethylene-vinyl alcohol copolymer itself, and orienting the barrier layer inside the material to form a barrier layer, thereby weakening the attack of the electrolyte on the molecular chains inside the material, and further improving the electrolyte resistance of the material. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0028] The sources of raw materials used in the present invention are as follows: The following polyamide resins were obtained by home-made methods: A-1 A-2 A-3 A-4 A-5 A-6 A-7 Terephthalic acid mol 5.5 6.5 7.0 7.5 8.5 5.0 9.0 1,10-Decanedioic acid mol 4.5 3.5 3.0 2.5 1.5 5.0 1.0 1,10-Decanediamine mol 10 10 10 10 10 10 10 Melting point, °C 258 263 265 273 286 252 292 Relative viscosity 2.5 2.6 2.6 2.7 2.5 2.6 2.6 B-1 B-2 B-3 B-4 B-5 B-6 Terephthalic acid mol 7.0 7.0 5.5 7.0 7.0 5.5 1,10-Decanedioic acid mol 1.5 1.5 3.0 1.0 1.5 3.0 1,12-Dodecanedioic acid mol 1.5 1.5 2.0 1.5 1.5 1,18-Octadecanedioic acid mol 1.5 1,10-Decanediamine mol 5.0 5.0 7.0 5.0 3.0 1,12-Dodecanediamine mol 5.0 5.0 3.0 5.0 7.0 10 Melting point, °C 260 258 253 259 252 250 Relative viscosity 2.6 2.6 2.6 2.5 2.6 2.7 N-ethyl-p-toluenesulfonamide: NEO / PTSA, Shouguang Nuomo Chemical Co., Ltd.; Dendritic polyamidoamine: CYD-120C, Weihai Chenyuan Molecular New Materials Co., Ltd.; 4,4'-Methylenebis(3-chloro-2,6-diethylaniline): MCDEA, Jinwotai Chemical Co., Ltd.; N,N'-bis(2,6-diisopropylphenyl)carbodiimide: BCM-011, Zhejiang Pukang Chemical Co., Ltd.; Diethyltoluenediamine: E-100, Shandong Tonglan Chemical Co., Ltd.; Ethylene-vinyl alcohol copolymer A: EVOH F101B, Kuraray Co., Ltd., Japan; Ethylene-vinyl alcohol copolymer B: OHBX-228, DuPont, USA; Maleic anhydride grafted POE-1: The maleic anhydride grafting rate is 1wt%, and it is made by mixing; Maleic anhydride grafted POE-2: The maleic anhydride grafting rate is 2wt%, and it is made by mixing; Maleic anhydride grafted POE-3: The maleic anhydride grafting rate is 3wt%, and it is made by mixing; Maleic anhydride grafted POE-4: The maleic anhydride grafting rate is 5wt%, which is made by mixing; The above maleic anhydride grafted POE is derived from POE DF640, Mitsui Chemicals, Singapore.

[0029] Maleic anhydride grafted SEBS: The maleic anhydride grafting rate is 2.5wt%, which is self-made by mixing. SEBS comes from Kraton G1652, Shell Company, USA; Maleic anhydride grafted EPDM: The maleic anhydride grafting rate is 2.5wt%. The maleic anhydride grafting rate is increased by mixing and kneading. The maleic anhydride grafted EPDM before further modification comes from FUSABOND N416, DuPont, USA; GMA grafted POE: POG-2821, Guangzhou Dongjin Plastic Technology Co., Ltd.; GMA grafted SEBS: KT-2511, Shenyang Ketong Company; POE: POE DF640, Mitsui Chemicals, Singapore.

[0030] Antioxidant: RIANOX 1098, Rianlon Corporation; Carbon black: M717, Cabot Corporation; Various test methods: (1) Coolant resistance: First test the initial elongation at break. Heat and melt the semi-aromatic polyamide composition at 260-300°C and injection mold it into tensile specimens A and B. Test specimen A for tensile properties according to international standard ISO 527-2019 to obtain the initial elongation at break. Place specimen B in an autoclave, mix ethylene glycol and deionized water in a volume ratio of 1:1, pour into the autoclave until the tensile specimen is completely immersed; then place the autoclave in a 135°C high-temperature oven for 2000 hours and take it out. Test the tensile properties of the aged tensile specimen according to international standard ISO 527-2019 to obtain the elongation at break after aging. The calculation method for the coolant resistance retention rate is: elongation at break after coolant test / initial elongation at break × 100%.

[0031] (2) Tolerance to electrolyte: First test the initial elongation at break, heat and melt the semi-aromatic polyamide composition at 260-300°C, and injection mold it into tensile specimens A and B. Specimen A is subjected to tensile performance test in accordance with international standard ISO 527-2019 to obtain the initial elongation at break. Specimen B is placed in a sealed glass container, and the electrolyte (EC / EMC / DMC (volume ratio 1:1:1) mixed solvent system, electrolyte is LiPF6, concentration is 1.5 mol / L) is poured into the container until the tensile specimen is completely immersed; then the container is placed in a high-temperature oven at 85°C for 2000 hours and then taken out. The tensile performance of the aged tensile specimen is tested in accordance with international standard ISO 527-2019 to obtain the elongation at break after aging. The calculation method for the electrolyte resistance retention rate is: elongation at break after electrolyte test / initial elongation at break × 100%.

[0032] Table 1: Content of each component and test results of semi-aromatic polyamide composite materials of Examples 1-6 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyamide resin A-1 80 90 100 90 90 90 Maleic anhydride grafted POE-1 5 15 30 Maleic anhydride grafted POE-2 15 Maleic anhydride grafted POE-3 15 Maleic anhydride grafted POE-4 15 N-Ethyl p-toluenesulfonamide 4 6 8 6 6 6 Ethylene-vinyl alcohol copolymer A 2 3 5 3 3 3 Antioxidants 0.5 Carbon Black 0.4 Initial elongation at break % 158 182 196 192 199 196 Coolant resistance retention rate% 39 39 42 43 43 38 Electrolyte resistance retention rate% 27 30 30 32 30 28 It can be seen from Examples 2 / 4-6 that the preferred maleic anhydride content can maintain higher resistance to coolant and electrolyte.

[0033] Table 2: Content of each component and test results of semi-aromatic polyamide composite materials of Examples 7-12 Example 7 Example 8 Example 9 Example 10 Embodiment 11 Example 12 Polyamide resin number A-1 A-1 A-2 A-3 A-4 A-5 Polyamide resin content 90 90 90 90 90 90 Maleic anhydride grafted POE-1 15 15 15 15 Maleic Anhydride Grafted SEBS 15 Maleic Anhydride Grafted EPDM 15 N-Ethyl p-toluenesulfonamide 6 6 6 6 6 6 Ethylene-vinyl alcohol copolymer A 3 3 3 3 3 3 Initial elongation at break % 173 172 176 168 159 152 Coolant resistance retention rate% 36 38 42 44 45 47 Electrolyte resistance retention rate% 28 28 32 34 35 36 It can be seen from Examples 2 / 9-12 that as the benzene ring content increases, the coolant resistance and electrolyte resistance increase. Combined with the initial elongation at break, it is preferred that the molar content of terephthalic acid in the diacid unit is 65-75 mol%.

[0034] Table 3: Content of each component and test results of semi-aromatic polyamide composite materials of Examples 13-16 Example 13 Embodiment 14 Embodiment 15 Example 16 Polyamide resin number B-1 B-2 B-3 A-1 Polyamide resin content 90 90 90 90 Maleic anhydride grafted POE-1 15 15 15 15 N-Ethyl p-toluenesulfonamide 6 6 6 6 Ethylene-vinyl alcohol copolymer A 3 3 3 Ethylene-vinyl alcohol copolymer B 3 Initial elongation at break % 172 175 192 180 Coolant resistance retention rate% 42 41 38 38 Electrolyte resistance retention rate% 30 30 28 29 Table 4: Content of each component and test results of semi-aromatic polyamide composite materials of Examples 17-20 Embodiment 17 Embodiment 18 Embodiment 19 Embodiment 20 Polyamide resin A-1 90 90 90 90 Maleic anhydride grafted POE-1 15 15 15 15 Dendritic polyamidoamine 6 4,4'-Methylenebis(3-chloro-2,6-diethylaniline) 6 N,N'-Bis(2,6-diisopropylphenyl)carbodiimide 6 Diethyltoluenediamine 6 Ethylene-vinyl alcohol copolymer A 3 3 3 3 Initial elongation at break % 177 175 177 178 Coolant resistance retention rate% 42 35 36 37 Electrolyte resistance retention rate% 34 26 27 29 It can be seen from Examples 2 / 17-20 that the preferred amine electrolyte resistance modifier has better coolant resistance retention rate and electrolyte resistance retention rate.

[0035] It can be seen from the above examples that the initial elongation at break of the semi-aromatic polyamide composite material of the present invention is greater than 150%, the elongation at break after aging in a coolant for 2000 hours is greater than 34%, and the elongation at break after aging in an electrolyte for 2000 hours is greater than 25%.

[0036] Table 5: Content of each component and test results of the semi-aromatic polyamide composite materials of Comparative Examples 1-5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polyamide resin number A-1 A-1 A-1 A-1 A-1 Polyamide resin content 90 90 90 90 90 Maleic anhydride grafted POE-1 15 15 GMA grafted POE 15 GMA Grafted SEBS 15 POE 15 N-Ethyl p-toluenesulfonamide 6 6 6 2 10 Ethylene-vinyl alcohol copolymer A 3 3 3 3 3 Initial elongation at break % 122 105 110 163 205 Coolant resistance retention rate% 27 26 22 31 35 Electrolyte resistance retention rate% 17 15 17 22 23 It can be seen from Comparative Examples 1-3 that, although the GMA-grafted toughening agent can also react with the end groups of polyamide compared to the non-grafted toughening agent, the effect of improving the resistance to coolants and electrolytes is not significant enough.

[0037] It can be seen from Comparative Examples 4 / 5 that when the content of the amine electrolyte resistance modifier is too low or too high, it is impossible to simultaneously have excellent coolant resistance and electrolyte resistance performance.

[0038] Table 6: Content of each component and test results of semi-aromatic polyamide composite materials of comparative examples 6-12 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Polyamide resin number A-1 A-5 A-6 A-7 B-4 B-5 B-6 Polyamide resin content 90 90 90 90 90 90 90 Maleic anhydride grafted POE-1 15 15 15 15 15 15 15 N-Ethyl p-toluenesulfonamide 6 6 6 6 6 6 6 Ethylene-vinyl alcohol copolymer A 0 10 3 3 3 3 3 Initial elongation at break % 188 136 192 126 187 195 198 Coolant resistance retention rate% 36 43 33 50 34 35 32 Electrolyte resistance retention rate% 20 32 24 38 24 21 22 It can be seen from Comparative Example 6 that the electrolyte resistance is insufficient when the ethylene-vinyl alcohol copolymer is not contained.

[0039] It can be seen from Comparative Example 7 that when the content of ethylene-vinyl alcohol copolymer is too high, the initial elongation at break is too low.

[0040] It can be seen from Comparative Example 8 that when the terephthalic acid content in the polyamide resin is too low, the retention rates of resistance to coolant and electrolyte are low.

[0041] It can be seen from Comparative Example 9 that when the terephthalic acid content in the polyamide resin is too high, the initial elongation at break is too low and it is not suitable for manufacturing pipelines.

[0042] It can be seen from Comparative Example 10 that even if the terephthalic acid content in the polyamide resin is within the specified range, when the proportion of 1,10-sebacic acid is too low, the coolant resistance and electrolyte resistance retention rates are low.

[0043] It can be seen from Comparative Examples 11 / 12 that when the content of decanediamine is too low or even no decanediamine is contained, the electrolyte resistance retention rate is low.

Claims

1. A semi-aromatic polyamide composite material, characterized in that: By weight, it includes the following components: 79-101 parts of semi-aromatic polyamide; 5-30 parts of maleic anhydride grafted toughening agent; 4-8 parts of amine electrolyte resistance modifier; 2-5 parts of ethylene-vinyl alcohol copolymer; The semi-aromatic polyamide is derived from the following units, measured in mole percentage: The diacid units are derived from terephthalic acid and a straight-chain diacid containing at least 10 carbon atoms, wherein terephthalic acid accounts for 55-85 mol% of the molar content of the diacid units, and the straight-chain diacid containing at least 10 carbon atoms is selected from at least one of 1,10-decanedioic acid, 1,12-dodecanedioic acid, and 1,18-octadecandioic acid, wherein 1,10-decanedioic acid accounts for 50-100 mol% of the total molar percentage content of the straight-chain diacid containing at least 10 carbon atoms; The diamine units are derived from 1,10-decanediamine and 1,12-dodecanediamine, wherein 1,10-decanediamine accounts for 50-100 mol% of the total molar percentage content of the diamine units; The amine electrolyte-resistant modifier is selected from at least one of N-ethyl-p-toluenesulfonamide, dendritic polyamidoamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), N,N'-di(2,6-diisopropylphenyl)carbodiimide and diethyltoluenediamine.

2. The semi-aromatic polyamide composite material according to claim 1, characterized in that: The amine electrolyte resistance modifier is selected from at least one of N-ethyl p-toluenesulfonamide and dendritic polyamide amine; more preferably, the amine electrolyte resistance modifier is selected from dendritic polyamide amine.

3. The semi-aromatic polyamide composite material according to claim 2, characterized in that: The molar content of terephthalic acid in diacid units is 65-75 mol%.

4. The semi-aromatic polyamide composite material according to claim 1, characterized in that: The maleic anhydride grafted toughening agent is selected from at least one of maleic anhydride grafted POE, maleic anhydride grafted SEBS and maleic anhydride grafted EPDM.

5. The semi-aromatic polyamide composite material according to claim 1, characterized in that: In the maleic anhydride grafted toughening agent, the grafting rate of maleic anhydride is 1-5wt%; preferably, in the maleic anhydride grafted toughening agent, the grafting rate of maleic anhydride is 2-3wt%.

6. The semi-aromatic polyamide composite material according to claim 1, characterized in that: The relative viscosity of the semi-aromatic polyamide is in the range of 2.4-3.

2.

7. The semi-aromatic polyamide composite material according to claim 1, characterized in that: By weight, the invention further comprises 0-3 parts of auxiliary agents, wherein the auxiliary agents are selected from at least one of UV stabilizers, heat stabilizers and pigments.

8. The method for preparing the semi-aromatic polyamide composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the components uniformly according to the proportion, extruding and granulating through a twin-screw extruder to obtain a semi-aromatic polyamide composite material.

9. Use of the semi-aromatic polyamide composite material according to any one of claims 1 to 7, characterized in that: Used to prepare liquid cooling lines.

10. A pipe prepared using the semi-aromatic polyamide composite material according to any one of claims 1 to 7.