Hydrolysis-resistant polyamide molding material and method for its production and use
By adding modified glass fiber and modified polysulfone to the polyamide matrix and using Friedel-Crafts acylation reaction to form molecular-level interfacial bonding, the hydrolysis problem of polyamide in high-temperature coolant environment is solved, and the high-temperature hydrolysis resistance is improved, meeting the long-term use requirements of cooling circuits in new energy vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG ALDEX NEW MATERIAL CO LTD
- Filing Date
- 2026-04-07
- Publication Date
- 2026-05-29
AI Technical Summary
Traditional polyamides are prone to hydrolysis in high-temperature coolant environments, leading to molecular chain breakage and failing to meet the long-term lifespan requirements of cooling circuits in new energy vehicles. Existing improvement solutions are costly, have narrow process windows, and poor interface compatibility.
PA6T/PA66 copolyamide is used as the matrix, and modified short-cut glass fiber and modified polysulfone are added. Carbon-carbon double bonds and carbonyl groups are introduced into the side chain of polysulfone through Friedel-Crafts acylation reaction, forming a molecular-level interface bond with polyamide. Ethylene-maleic anhydride copolymer is added to improve compatibility and form a molecular-level cross-linked structure to block water molecule penetration.
After being stored at 130℃ in a 1:1 ethylene glycol/water mixture for 1000 hours, the fracture stress retention rate is ≥90%, and the material maintains structural stability under long-term high temperature and high humidity conditions, meeting the life requirements of the cooling circuit of new energy vehicles.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials technology, specifically relating to a hydrolysis-resistant polyamide molding material, its preparation method, and its application. Background Technology
[0002] Polyamide (PA), one of the five major engineering plastics, is widely used in high-end fields such as automobiles, electronics, and new energy due to its advantages such as high strength, wear resistance, chemical resistance, and ease of processing. However, the amide bonds in the traditional PA66 molecular chain readily form hydrogen bonds with water molecules, leading to reversible hydrolysis in a high-temperature coolant (ethylene glycol / water) environment, resulting in molecular chain breakage and a sharp drop in mechanical properties. Studies have shown that after aging in a 50% ethylene glycol solution at 120℃ for 1000 hours, the fracture stress retention rate of PA66 is often less than 40%, which cannot meet the 1000–1500 hour lifespan requirement of cooling circuits in new energy vehicles.
[0003] To delay hydrolysis, the industry commonly employs solutions such as carbodiimide hydrolysis stabilizers or blends with long-chain nylons, but these methods suffer from drawbacks such as high cost, narrow process window, and poor interfacial compatibility. Furthermore, existing technologies largely focus on short-term evaluations at 135°C for 72 hours, lacking long-term data support at 130°C and ≥1000 hours. Therefore, developing a molding compound with long-term high-temperature hydrolysis resistance has significant engineering value and industrial implications. Summary of the Invention
[0004] The purpose of this invention is to provide a hydrolysis-resistant polyamide molding material, its preparation method, and its application, which can solve the problem of poor long-term high-temperature hydrolysis resistance of polyamides in the prior art.
[0005] The objective of this invention can be achieved through the following technical solutions: A hydrolysis-resistant polyamide molding material, comprising the following raw materials by weight: 100 parts PA6T / PA66 copolyamide, 10-30 parts modified chopped glass fiber, 15-25 parts modified polysulfone, 1-5 parts ethylene-maleic anhydride copolymer, and 1-5 parts functional additives. The modified polysulfone is produced by Friedel-Crafts acylation of polysulfone with acryloyl chloride, which introduces carbon chains containing carbon-carbon double bonds and carbonyl groups by branching onto the side of the benzene ring.
[0006] Because glass fiber itself does not absorb moisture, it will not swell or decompose when exposed to water, maintaining high strength and mechanical properties even in humid and hot environments. Adding glass fiber to a polyamide matrix reduces hydrolytic weaknesses in the material. Treatment with a silane coupling agent creates a strong bond between the glass fiber and polyamide, improving hydrolysis resistance. However, simply modifying chopped glass fiber offers limited improvement in hydrolysis resistance. Under prolonged humid and hot conditions, although the glass fiber itself does not absorb moisture, moisture gradually penetrates into the polyamide matrix, disrupting the original interfacial adhesion between the fiber and matrix. This prevents effective stress transfer, leading to polyamide molecular chain breakage and a decline in the overall performance of the composite material.
[0007] This invention adds modified polysulfone along with modified chopped glass fiber. Polysulfone exhibits excellent hydrolysis resistance, with its molecular chain containing benzene rings, ether bonds, and sulfone groups. It possesses good stability at high temperatures and is difficult to hydrolyze. Adding it to a polyamide matrix can block the penetration and diffusion of water molecules. However, polysulfone has poor compatibility with polyamide; direct addition can lead to phase separation after processing. The modified polysulfone in this invention introduces carbon-carbon double bonds and carbonyl groups into its side chains. The introduced carbonyl groups can form hydrogen bonds with the amino or amide bonds at the polyamide chain ends, significantly improving compatibility. Polysulfone is uniformly dispersed in the matrix. Furthermore, the introduced carbon-carbon double bond groups are key active groups. During melt processing, thermally initiated addition reactions occur between the double bonds and the terminal amino groups of the polyamide, forming covalent bonds between the modified polysulfone and the polyamide, achieving molecular-level interfacial bonding. In addition, the simultaneous addition of ethylene-maleic anhydride copolymer enhances the thermodynamic affinity between the nonpolar ethylene segments and the main chain structure of the modified polysulfone. The maleic anhydride segments react with the terminal amino groups of the polyamide, exhibiting affinity for both modified polysulfone and polyamide at one end, thus bridging the gap between the two materials and promoting compatibility. The reaction of modified polysulfone and ethylene-maleic anhydride copolymer with the terminal amino groups of the polyamide weakens the interaction between the polar groups of the polyamide and water. Furthermore, the introduction of hydrolysis-resistant molecular chains at both ends of the polyamide molecular chain creates a covering and cross-linking effect, hindering water penetration and further improving the material's hydrolysis resistance. The molecular-level cross-linking structure ensures the material maintains structural stability under long-term high temperature and high humidity conditions.
[0008] Furthermore, according to ISO 527, the molding material retains ≥90% of its fracture stress after being stored at 130°C in a 1:1 weight ratio of ethylene glycol / water mixture for 1000 hours.
[0009] Furthermore, the molar ratio of 6T to 66 units in the PA6T / PA66 copolyamide is (6:4) to (8:2).
[0010] The PA6T / PA66 copolyamide used in this invention is a random copolymer obtained by melt polycondensation of terephthalic acid (6T) units, adipic acid (66) units, and hexamethylenediamine. It has a melting point of 295–315°C and a viscosity (VN) of 140–160 mL / g (ISO 307, 25°C) measured in 96% sulfuric acid. The molar ratio of 6T to 66 structural units is controlled between (6:4) and (8:2) to ensure sufficient aromatic ring density to inhibit water molecule penetration while retaining an appropriate amount of aliphatic segments to ensure melt flowability.
[0011] Furthermore, the modified chopped glass fibers have a diameter of 5–20 μm and a length of 2–50 mm.
[0012] Furthermore, the modified chopped glass fiber is a γ-aminopropyltriethoxysilane-modified chopped alkali-free glass fiber.
[0013] Furthermore, the preparation steps of the modified polysulfone are as follows: The dried polysulfone (PSU) was dispersed in dichloromethane, a Lewis acid catalyst was added, and the mixture was stirred until homogeneous. The mixture was placed in an ice bath, and acryloyl chloride was slowly added under a nitrogen atmosphere. The mixture was stirred for 4-6 hours, then removed from the ice bath and stirred at a constant temperature of 25-35°C for 3-8 hours. The mixture was washed with dilute hydrochloric acid, and after washing, ethanol was added as a precipitant to collect the precipitate. After purification and drying, the modified polysulfone was obtained.
[0014] In the above scheme, the Lewis acid catalyst forms a complex with the chlorine atom of acryloyl chloride. The dissociation of chlorine forms an acyl carbocation, which electrophilically attacks the aromatic ring, completing the grafting onto the benzene ring of polysulfone (PSU) via Friedel-Crafts acylation. A carbonyl group is attached to the benzene ring of the grafted polysulfone, with a double bond at the ortho position. Due to the strong electronegativity of the carbonyl group, it has a strong attraction for electrons, causing the electron cloud to be pulled towards the carbonyl oxygen atom, resulting in a partially positively charged double bond. Because the β-carbon is electron-deficient, nucleophilic addition readily occurs, promoting the reaction between the grafted double bond and the amino group on the polyamide, which is beneficial for the molecular-level bonding of the modified polysulfone to the polyamide matrix.
[0015] Furthermore, the Lewis acid catalyst is one of aluminum trichloride and tin tetrachloride; The molar ratio of the Lewis acid catalyst to acryloyl chloride is 1-1.2:1.
[0016] Furthermore, the acryloyl chloride is 4-16% of the mass of polysulfone (PSU). The grafting rate of the acryloyl chloride controls the compatibility of the modified polysulfone.
[0017] Furthermore, the functional additives include heat stabilizers, lubricants, and color masterbatches.
[0018] Furthermore, the heat stabilizer is at least one of a copper compound, an aromatic secondary amine, and a sterically hindered phenol; The heat stabilizer is 0.1-5% of the mass of PA6T / PA66 copolyamide.
[0019] Furthermore, the copper compound comprises CuI and KI in a molar ratio of 1:4, and is added at an amount of 0.25-0.35% of the mass of the PA6T / PA66 copolyamide.
[0020] It provides long-lasting thermo-oxidative stability and forms a Cu-amine complex with the PA6T / 66 end group, inhibiting high-temperature hydrolysis and chain breakage.
[0021] Furthermore, the aromatic secondary amine is 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, added at 0.35–0.45% of the mass of the PA6T / PA66 copolyamide. It exhibits a synergistic effect with the copper salt, capturing free radicals and regenerating phenolic hydroxyl groups.
[0022] Furthermore, the hindered phenol is antioxidant 1098, added at 0.2-0.3% of the mass of PA6T / PA66 copolyamide, for primary antioxidant use during the processing stage.
[0023] Furthermore, the lubricant is at least one of ethylene bis-stearamide and calcium lignite; the lubricant is 0.05-1 wt% of the mass of PA6T / PA66 copolyamide.
[0024] Reduce screw torque, improve melt flowability, and enhance demolding performance.
[0025] Furthermore, the color masterbatch is carbon black masterbatch, and the color masterbatch is 1.0-1.2% of the mass of PA6T / PA66 copolyamide.
[0026] This invention also provides a method for preparing a hydrolysis-resistant polyamide molding material, which includes the following steps: Prepare raw materials according to the proportions, premix the raw materials, and then melt-blend, extrude, injection mold, or compression mold at 220–340℃.
[0027] The present invention also provides an application of a hydrolysis-resistant polyamide molding material, wherein the hydrolysis-resistant polyamide molding material described above is used to prepare structural components that are in continuous contact with high-temperature coolant; The structural components include, but are not limited to, automotive engine cooling circuit components and new energy vehicle thermal management system components.
[0028] The beneficial effects of this invention are: This invention replaces traditional pure PA66 with PA6T / PA66 copolyamide. By increasing the benzene ring density in the copolymer, water molecule penetration is inhibited, and the optimized ratio ensures good processing flowability. Modified chopped glass fibers are added to the polyamide matrix. The modified, low-hygroscopic glass fibers are uniformly dispersed in the matrix, reducing hydrolytic weaknesses from a physical barrier perspective. Simultaneously, modified polysulfone is added. The modified polysulfone, through grafted carbonyl groups and double bonds, undergoes molecular-level bonding with the polyamide matrix during processing and melting. By forming chemical bonds with the terminal amino groups of the polyamide, hydrolysis-resistant molecular chains are introduced at both ends of the polyamide molecular chains, forming a covering and cross-linking effect that hinders water penetration, further improving the hydrolysis resistance of the molding material. The molecular-level cross-linking structure ensures structural stability under long-term high temperature and high humidity conditions, resulting in excellent long-term high-temperature hydrolysis resistance of the molding material. Detailed Implementation
[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0030] Example 1 Preparation of modified polysulfone: Polysulfone (PSU) was dried in a drying oven at 130°C for 10 hours. 100 g of the dried PSU was weighed and dissolved in 1 L of dichloromethane by ultrasonic dispersion. 15 g (0.11 mol) of aluminum trichloride was added to the solution and stirred for 3 minutes to make the material uniform. The solution was placed in an ice bath at 0-5°C and 9 g (0.1 mol) of acryloyl chloride was slowly added under a nitrogen atmosphere. The mixture was stirred for 5 hours and then removed from the ice bath. The mixture was stirred at 30°C for 6 hours. The product was washed with 1 mol / L dilute hydrochloric acid to remove residual catalyst. The polymer was then precipitated in ethanol. The precipitate was collected and washed with DMF and water sequentially to remove chloride ions. The product was then vacuum dried to obtain modified polysulfone.
[0031] A hydrolysis-resistant polyamide molding material, the raw materials are prepared according to the following parts by weight: 100 parts of PA6T / PA66 copolyamide (molar ratio of 6T to 66 structural units is 6:4), 20 parts of modified short-cut glass fiber (modified γ-aminopropyltriethoxysilane modified short-cut alkali-free glass fiber, diameter 5–20 μm, length 2–50 mm), 20 parts of modified polysulfone, 3 parts of ethylene-maleic anhydride copolymer, 0.3 parts of CuI and KI mixture (molar ratio of CuI and KI is 1:4), 0.4 parts of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 0.25 parts of antioxidant 1098, 0.5 parts of ethylene bis-stearamide, and 1 part of carbon black masterbatch (40 wt% carbon black + 60 wt% PA6 carrier).
[0032] The prepared raw materials are put into a high-speed mixer and premixed at 1000 rpm for 5 minutes. Then, they are put into a twin-screw extruder (screw length-to-diameter ratio L / D is 40, diameter is 26 mm). The temperatures of each section are set as follows: 260°C, 270°C, 275°C, 280°C, 275°C (die head), screw speed is 250 rpm, feed rate is 20 kg / h, vacuum degree is -0.085 MPa, melt blending and extrusion are performed, the melt is stretched through a 4 mm die head, cooled in a water bath to ≤40°C, and pelletized to 2.5 mm. The pellets are then fed into an injection molding machine (injection molding machine screw length-to-diameter ratio 20, equipped with a closed-loop PID mold temperature controller, oil temperature 80±2°C). The melt temperature is 280°C, the mold temperature is 80°C, the injection pressure is 80 MPa, the cooling time is 25 s, and the finished product is obtained by injection molding.
[0033] Example 2 The only difference from Example 1 is that, in preparing the modified polysulfone, the mass of acryloyl chloride was adjusted to 16g (0.18mol) and the mass of aluminum trichloride was adjusted to 26g (0.19mol), while other reaction conditions remained unchanged.
[0034] Example 3 The only difference from Example 1 is that, in preparing the modified polysulfone, the mass of acryloyl chloride was adjusted to 4 g (0.044 mol), and the mass of aluminum trichloride was adjusted to 6.5 g (0.049 mol), while other reaction conditions remained unchanged.
[0035] Example 4 The only difference from Example 1 is that the mass fraction of modified polysulfone in the hydrolysis-resistant polyamide molding material is adjusted to 15 parts.
[0036] Example 5 The only difference from Example 1 is that the mass fraction of modified polysulfone in the hydrolysis-resistant polyamide molding material is adjusted to 25 parts.
[0037] Examples 6-7 The only difference from Example 1 is that the proportion of raw materials in the hydrolysis-resistant polyamide molding material is different, as shown in Table 1.
[0038] Table 1
[0039] Comparative Example 1 The only difference from Example 1 is that butyryl chloride is used instead of acryl chloride when preparing the modified polysulfone.
[0040] Preparation of modified polysulfone: Polysulfone (PSU) was dried in a drying oven at 130°C for 10 hours. 100 g of the dried PSU was weighed and dissolved in 1 L of dichloromethane by ultrasonic dispersion. 15 g (0.11 mol) of aluminum trichloride was added to the solution and stirred for 3 minutes to make the material uniform. The solution was placed in an ice bath at 0-5°C and 10.6 g (0.1 mol) of butyryl chloride was slowly added under a nitrogen atmosphere. The mixture was stirred for 5 hours and then removed from the ice bath. The mixture was stirred at 30°C for 6 hours. The product was washed with 1 mol / L dilute hydrochloric acid to remove residual catalyst. The polymer was then precipitated in ethanol. The precipitate was collected and washed with DMF and water sequentially to remove chloride ions. The product was then vacuum dried to obtain modified polysulfone.
[0041] A hydrolysis-resistant polyamide molding material, the raw materials are prepared according to the following parts by weight: 100 parts of PA6T / PA66 copolyamide (molar ratio of 6T to 66 structural units is 6:4), 20 parts of modified short-cut glass fiber (modified γ-aminopropyltriethoxysilane modified short-cut alkali-free glass fiber, diameter 5–20 μm, length 2–50 mm), 20 parts of modified polysulfone, 3 parts of ethylene-maleic anhydride copolymer, 0.3 parts of CuI and KI mixture (molar ratio of CuI and KI is 1:4), 0.4 parts of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 0.25 parts of antioxidant 1098, 0.5 parts of ethylene bis-stearamide, and 1 part of carbon black masterbatch (40 wt% carbon black + 60 wt% PA6 carrier).
[0042] The prepared raw materials are put into a high-speed mixer and premixed at 1000 rpm for 5 minutes. Then, they are put into a twin-screw extruder (screw length-to-diameter ratio L / D is 40, diameter is 26 mm). The temperatures of each section are set as follows: 260°C, 270°C, 275°C, 280°C, 275°C (die head), screw speed is 250 rpm, feed rate is 20 kg / h, vacuum degree is -0.085 MPa, melt blending and extrusion are performed, the melt is stretched through a 4 mm die head, cooled in a water bath to ≤40°C, and pelletized to 2.5 mm. The pellets are then fed into an injection molding machine (injection molding machine screw length-to-diameter ratio 20, equipped with a closed-loop PID mold temperature controller, oil temperature 80±2°C). The melt temperature is 280°C, the mold temperature is 80°C, the injection pressure is 80 MPa, the cooling time is 25 s, and the finished product is obtained by injection molding.
[0043] Comparative Example 2 The only difference from Example 1 is that in the hydrolysis-resistant polyamide molding material, polysulfone PSU is directly used instead of modified polysulfone.
[0044] A hydrolysis-resistant polyamide molding material, the raw materials are prepared according to the following parts by weight: 100 parts of PA6T / PA66 copolyamide (molar ratio of 6T to 66 structural units is 6:4), 20 parts of modified short-cut glass fiber (gamma-aminopropyltriethoxysilane modified short-cut alkali-free glass fiber, diameter 5–20 μm, length 2–50 mm), 20 parts of polysulfone PSU, 3 parts of ethylene-maleic anhydride copolymer, 0.3 parts of CuI and KI mixture (molar ratio of CuI and KI is 1:4), 0.4 parts of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 0.25 parts of antioxidant 1098, 0.5 parts of ethylene bis-stearamide, and 1 part of carbon black masterbatch (40 wt% carbon black + 60 wt% PA6 carrier).
[0045] The prepared raw materials are put into a high-speed mixer and premixed at 1000 rpm for 5 minutes. Then, they are put into a twin-screw extruder (screw length-to-diameter ratio L / D is 40, diameter is 26 mm). The temperatures of each section are set as follows: 260°C, 270°C, 275°C, 280°C, 275°C (die head), screw speed is 250 rpm, feed rate is 20 kg / h, vacuum degree is -0.085 MPa, melt blending and extrusion are performed, the melt is stretched through a 4 mm die head, cooled in a water bath to ≤40°C, and pelletized to 2.5 mm. The pellets are then fed into an injection molding machine (injection molding machine screw length-to-diameter ratio 20, equipped with a closed-loop PID mold temperature controller, oil temperature 80±2°C). The melt temperature is 280°C, the mold temperature is 80°C, the injection pressure is 80 MPa, the cooling time is 25 s, and the finished product is obtained by injection molding.
[0046] Comparative Example 3 The only difference from Example 1 is that no modified polysulfone is added to the hydrolysis-resistant polyamide molding material.
[0047] A hydrolysis-resistant polyamide molding material, the raw materials are prepared according to the following parts by weight: 100 parts of PA6T / PA66 copolyamide (molar ratio of 6T to 66 structural units is 6:4), 20 parts of modified short-cut glass fiber (short-cut alkali-free glass fiber modified with γ-aminopropyltriethoxysilane, diameter 5–20 μm, length 2–50 mm), 3 parts of ethylene-maleic anhydride copolymer, 0.3 parts of CuI and KI mixture (molar ratio of CuI and KI is 1:4), 0.4 parts of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 0.25 parts of antioxidant 1098, 0.5 parts of ethylene bis-stearamide, and 1 part of carbon black masterbatch (40 wt% carbon black + 60 wt% PA6 carrier).
[0048] The prepared raw materials are put into a high-speed mixer and premixed at 1000 rpm for 5 minutes. Then, they are put into a twin-screw extruder (screw length-to-diameter ratio L / D is 40, diameter is 26 mm). The temperatures of each section are set as follows: 260°C, 270°C, 275°C, 280°C, 275°C (die head), screw speed is 250 rpm, feed rate is 20 kg / h, vacuum degree is -0.085 MPa, melt blending and extrusion are performed, the melt is stretched through a 4 mm die head, cooled in a water bath to ≤40°C, and pelletized to 2.5 mm. The pellets are then fed into an injection molding machine (injection molding machine screw length-to-diameter ratio 20, equipped with a closed-loop PID mold temperature controller, oil temperature 80±2°C). The melt temperature is 280°C, the mold temperature is 80°C, the injection pressure is 80 MPa, the cooling time is 25 s, and the finished product is obtained by injection molding.
[0049] The hydrolytic aging performance of the finished products prepared in Examples 1-7 and Comparative Examples 1-3 was tested. The finished products were suspended in a 1:1 mass ratio of ethylene glycol / deionized water mixture and refluxed at 130±2℃ and atmospheric pressure for 1000h. After aging, they were removed, dried, and conditioned at 23℃ and 50%RH for 24h before testing. The tensile strength test was performed according to standard ISO 527-1:2019, using type 1A specimens, with a tensile rate of 5mm·min. -1 The bending performance test references ISO 178:2019, with a specimen size of 80×10×4mm, a span of 64mm, and a speed of 2mm·min. -1 The unnotched impact strength test referenced the standard ISO 179-1:2019, 1eU type, with a pendulum energy of 4J. The retention rate was calculated as strength after aging / initial strength. The surface of the finished product after hydrolysis aging was evaluated, and the silver streaks and bubbles were visually inspected. The results are shown in Table 2.
[0050] Table 2
[0051] As can be seen from Table 1, the addition of modified polysulfone to polyamide molding materials, in combination with other raw materials, is beneficial to improving the hydrolysis resistance of the materials. Combined with the results of Comparative Examples 1, 2 and 3, it can be seen that the modified polysulfone, through the introduction of double bonds and carbonyl groups by grafting, can promote compatibility with the matrix, reduce hydrolysis weak points in the material, inhibit water penetration, and slow down the hydrolysis process.
[0052] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A hydrolysis-resistant polyamide molding material, characterized in that, By weight, it includes the following raw materials: 100 parts PA6T / PA66 copolyamide, 10-30 parts modified chopped glass fiber, 15-25 parts modified polysulfone, 1-5 parts ethylene-maleic anhydride copolymer, and 1-5 parts functional additives. The modified polysulfone is produced by Friedel-Crafts acylation of polysulfone with acryloyl chloride, which introduces carbon chains containing carbon-carbon double bonds and carbonyl groups by branching onto the side of the benzene ring.
2. The hydrolysis-resistant polyamide molding material according to claim 1, characterized in that, According to ISO 527, the molding material retains ≥90% of its fracture stress after being stored at 130°C in a 1:1 weight ratio of ethylene glycol / water mixture for 1000 hours.
3. The hydrolysis-resistant polyamide molding material according to claim 1, characterized in that, The molar ratio of 6T to 66 units in the PA6T / PA66 copolyamide is (6:4) to (8:2).
4. The hydrolysis-resistant polyamide molding material according to claim 1, characterized in that, The modified chopped glass fiber is a γ-aminopropyltriethoxysilane-modified chopped alkali-free glass fiber.
5. The hydrolysis-resistant polyamide molding material according to claim 1, characterized in that, The preparation steps of the modified polysulfone are as follows: The dried polysulfone (PSU) was dispersed in dichloromethane, a Lewis acid catalyst was added, and the mixture was stirred until homogeneous. The mixture was placed in an ice bath, and acryloyl chloride was slowly added under a nitrogen atmosphere. The mixture was stirred for 4-6 hours, then removed from the ice bath and stirred at a constant temperature of 25-35°C for 3-8 hours. Sodium hydroxide solution was added, the precipitate was collected, purified, and dried to obtain the modified polysulfone.
6. The hydrolysis-resistant polyamide molding material according to claim 5, characterized in that, The Lewis acid catalyst is one of aluminum trichloride and tin tetrachloride; The molar ratio of the Lewis acid catalyst to acryloyl chloride is 1-1.2:
1.
7. The hydrolysis-resistant polyamide molding material according to claim 5, characterized in that, The acryloyl chloride is 4-16% of the mass of polysulfone (PSU).
8. The hydrolysis-resistant polyamide molding material according to claim 1, characterized in that, The functional additives include heat stabilizers, lubricants, and color masterbatches; The heat stabilizer is at least one of copper compound, aromatic secondary amine and hindered phenol; The heat stabilizer is 0.1-5% of the mass of PA6T / PA66 copolyamide.
9. A method for preparing a hydrolysis-resistant polyamide molding material, characterized in that, The preparation of the hydrolysis-resistant polyamide molding material as described in any one of claims 1-8 includes the following steps: Prepare raw materials according to the proportions, premix the raw materials, and then melt-blend, extrude, injection mold, or compression mold at 220–340℃.
10. An application of a hydrolysis-resistant polyamide molding material, characterized in that, The hydrolysis-resistant polyamide molding material according to any one of claims 1-8 is used to prepare structural components that are in continuous contact with high-temperature coolant.