High-temperature-resistant PPS material for automobile parts and preparation method of high-temperature-resistant PPS material

Abstract

The invention discloses a high-temperature-resistant PPS material for automobile parts and a preparation method thereof.The high-temperature-resistant PPS material is prepared from, by weight, 50-70 parts of PPS resin, 15-25 parts of modified PEEK resin, 12-16 parts of modified carbon fibers, 2-4 parts of modified nano molybdenum disulfide, 1-3 parts of a flame retardant and 0.5-1.5 parts of a lubrication.The modified PEEK resin is used for conducting blending modification on the PPS resin, so that the flame retardance of the PPS resin is improved; meanwhile, the modified carbon fiber and the modified nano molybdenum disulfide are added to reinforce the material, so that the thermal oxidation stability and the mechanical property are remarkably improved while the processability of the PPS resin is maintained, and the PPS resin is particularly suitable for being applied to various high-temperature working conditions of automobile parts.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a high-temperature resistant PPS material for automotive parts and a preparation method thereof. Background Art

[0002] Polyphenylene sulfide (PPS), also known as polyphenyl sulfide, is a high-performance thermoplastic resin. As a special engineering plastic, PPS has excellent flame retardancy, with an oxygen index of over 44%, and is classified as a high flame retardant material. In addition, PPS also has good chemical corrosion resistance, showing high stability to a variety of acids, esters, ketones, phenols and hydrocarbon compounds. The mechanical properties of PPS are also excellent, especially its rigidity and wear resistance. The mechanical properties of PPS resin are good. Pure PPS has good creep resistance under load, and its hardness and wear resistance are very high. Due to its unique properties and characteristics, PPS has been widely used in engineering fields such as automotive, aviation and aerospace.

[0003] However, sulfur atoms in the PPS molecular chain exist in a divalent state, and the outermost electrons are unstable and easily form different valence states. At the same time, the bond energy of the C-S bond in the PPS molecular chain is relatively low, and it is easy to break to generate free radicals in a thermal oxygen environment, resulting in easy oxidation of PPS and loss of strength. High-temperature use environments can easily cause oxidation of PPS, causing damage to PPS materials and shortening their service life. Therefore, antioxidant modification of PPS resin and products has become an urgent problem to be solved. Adding hindered phenol antioxidants can improve the stability of polymers by absorbing free radicals generated during polymer degradation. However, low-molecular-weight antioxidants are prone to physical losses such as volatilization, migration and water extraction, resulting in loss of polymer stability. In addition, in order to meet the high impact resistance application scenarios of automotive parts, it is often necessary to further improve its mechanical strength and rigidity through reinforcement modification. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-temperature resistant PPS material for automotive parts and a preparation method thereof. The PPS resin is blended and modified with a modified PEEK resin, and at the same time, modified carbon fiber and modified nano-molybdenum disulfide are added to enhance the material, significantly improving the thermal oxygen stability and mechanical properties of the material.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A high-temperature resistant PPS material for automotive parts, comprising the following components in parts by weight: 50 - 70 parts of PPS resin, 15 - 25 parts of modified PEEK resin, 12 - 16 parts of modified carbon fiber, 2 - 4 parts of modified nano-molybdenum disulfide, 1 - 3 parts of flame retardant, and 0.5 - 1.5 parts of lubricant;

[0007] The modified PEEK resin is a PEEK resin with carboxylated surface;

[0008] The modified carbon fiber is a carbon fiber with aminated surface;

[0009] The modified nano-molybdenum disulfide is obtained by surface modification of nano-molybdenum disulfide with a silane coupling agent and then in-situ polymerization grafting of a hindered phenol antioxidant. The hindered phenol antioxidant is a triazine ring hindered phenol antioxidant, and its structural formula is as follows:

[0010]

[0011] Preferably, the flame retardant is a mixture of magnesium hydroxide and zinc borate in a mass ratio of 3:1.

[0012] Preferably, the lubricant is a mixture of polytetrafluoroethylene micropowder and silicone complex in a mass ratio of 4:1.

[0013] Preferably, the modified PEEK resin is prepared by chemical oxidation method, plasma treatment method, ultraviolet ozone treatment method or bio-enzyme catalysis method.

[0014] Preferably, the modified carbon fiber is prepared by surface modification with γ-aminopropyltriethoxysilane.

[0015] Preferably, the preparation method of the hindered phenol antioxidant comprises the following steps:

[0016] A1. Under nitrogen protection, cyanuric chloride reacts with 3,5-di-tert-butyl-4-hydroxybenzoic acid in tetrahydrofuran, adding Na2CO3 as an acid-binding agent, reacting at 55-70 °C for 10-12 h to obtain intermediate A;

[0017] A2. Phosphorus pentoxide is added to isooctanol with stirring at room temperature, controlling the temperature not exceeding 50 °C. After adding, the temperature is raised to 70-80 °C and reacted for 2-3 h, then cooled to 45-50 °C, neutralized with sodium hydroxide solution to pH 7-8, adding n-hexane, extracting and separating, collecting the organic phase, and acidifying and recovering to obtain diisooctyl phosphate;

[0018] A3. Intermediate A and diisooctyl phosphate are refluxed in toluene, adding 4-dimethylaminopyridine as a catalyst, refluxing at 120 °C for 4-8 h, introducing a phosphate group through an ester exchange reaction;

[0019] A4. Using gradient crystallization method, first removing the unreacted substances with n-hexane, and then recrystallizing with 90Vol% ethanol solution to obtain white needle-like crystals, namely the hindered phenol antioxidant.

[0020] Preferably, the molar ratio of cyanuric chloride to 3,5-di-tert-butyl-4-hydroxybenzoic acid in step A1 is 1:3.

[0021] Preferably, the molar ratio of intermediate A to diisooctyl phosphate in step A3 is 1:1.2.

[0022] Preferably, the preparation method of the modified nano-molybdenum disulfide comprises the following steps:

[0023] B1. Disperse the molybdenum disulfide nanosheets in a 95 Vol% ethanol solution, ultrasonically treat for 1 - 2 h, add γ-aminopropyltriethoxysilane, reflux at 80 °C for 4 - 8 h, centrifuge and wash with ethanol 3 - 5 times, and vacuum dry at 60 °C to obtain amino-functionalized nano-molybdenum disulfide;

[0024] B2. Ultrasonically disperse the amino-functionalized nano-molybdenum disulfide in N,N-dimethylformamide for 20 - 40 min to form a stable suspension, then add a hindered phenol antioxidant and N,N'-dicyclohexylcarbodiimide, heat up to 60 °C under nitrogen protection, and magnetically stir and react for 20 - 24 h in the dark. After the reaction is completed, wash with N,N-dimethylformamide, tetrahydrofuran, and methanol 3 - 5 times respectively, and vacuum dry at 50 °C to obtain the modified nano-molybdenum disulfide.

[0025] A preparation method of a high-temperature resistant PPS material for automotive parts comprises the following steps:

[0026] S1. First, vacuum dry PPS and the modified PEEK resin at 120 °C for 4 - 6 h respectively, then add the PPS resin and the modified PEEK resin into a mixer and knead at 280 °C for 5 - 10 min;

[0027] S2. Add the modified carbon fiber and the modified nano-molybdenum disulfide, knead at 290 °C for 5 - 10 min, and finally add the flame retardant and the lubricant, knead at 240 °C for 2 - 4 min to obtain a mixture;

[0028] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is: zone 1 at 280 °C, zone 2 at 300 °C, zone 3 at 300 °C, zone 4 at 310 °C, zone 5 at 310 °C, zone 6 at 305 °C, the screw speed is 200 rpm, and the shear rate is 1500 s -1 ;

[0029] S4. Extrude the melt-blended material through a twin-screw extruder, injection mold, control the mold temperature at 140 °C, the injection pressure at 80 - 100 MPa, the holding pressure time at 15 s / mm, then press-mold, preheat at 290 °C for 8 - 10 min first, hot press at 310 °C and 10 MPa for 6 - 8 min, and finally cold press to room temperature at 100 °C and 15 MPa to obtain the high-temperature resistant PPS material for automotive parts.

[0030] The beneficial effects of the present invention:

[0031] The present invention uses modified PEEK resin to blend and modify PPS resin, and at the same time adds modified carbon fiber and modified nano-molybdenum disulfide to enhance the material. While maintaining the processing performance of PPS, the thermal oxygen stability and mechanical properties are significantly improved, which is particularly suitable for various high-temperature working conditions applications of new energy vehicle components.

[0032] Among them, the glass transition temperature of the amorphous region of PEEK resin is high, and its heat resistance is the most excellent among thermoplastic resins. At the same time, it also has excellent comprehensive mechanical properties. The introduction of PEEK resin can improve the toughness and heat resistance of PPS resin.

[0033] The modified carbon fiber is treated with a silane coupling agent, which can improve the compatibility between the surface of the carbon fiber and PPS resin. Moreover, the amino-functionalized carbon fiber forms a hydrogen bond network with the hydroxyl group of the modified PEEK resin, further improving the mechanical properties of the material.

[0034] The modified nano-molybdenum disulfide is graft-modified with a hindered phenol antioxidant. Nano-molybdenum disulfide itself can endow polymer materials with wear resistance and self-lubrication properties. Utilizing the nano-synergistic effect, the migration rate of the hindered phenol antioxidant is reduced, and a slow-release effect can be achieved, enabling the material to have a lasting thermal oxidation resistance ability. The hindered phenol antioxidant provides a rigid planar structure with a triazine core to inhibit molecular thermal motion. The antioxidant efficiency of the multi-site hindered phenol structure is higher than that of traditional antioxidants. The phosphate ester group can capture the free radicals generated by the degradation of PPS, further improving the antioxidant effect. The isooctyl side chain is used to improve the compatibility with PPS.

[0035] In addition, the hindered phenol antioxidant of the present invention is rich in N and P elements, which can decompose to produce phosphate esters and gases at high temperatures, promote the dehydration and carbonization of the polymer, and at the same time form a carbonaceous protective layer. The non-combustible gases generated by decomposition also have a gas-phase flame retardant effect, while the nano-molybdenum disulfide lamellae can block the oxygen diffusion path. Therefore, the modified nano-molybdenum disulfide also has a certain flame retardant effect.

[0036] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. Brief Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 It is the infrared spectrum of the hindered phenol antioxidant prepared in Example 1. Detailed Embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0040] Example 1

[0041] A preparation method of a hindered phenol antioxidant includes the following steps:

[0042] A1. Under nitrogen protection, 3.68 g of cyanuric chloride and 15.02 g of 3,5 - di - tert - butyl - 4 - hydroxybenzoic acid are reacted in 100 ml of tetrahydrofuran, 1.04 g of Na2CO3 is added as an acid - binding agent, and the reaction is carried out at 60 °C for 12 h to obtain intermediate A;

[0043] A2. At room temperature, 2.8 g of phosphorus pentoxide is added to 30 ml of isooctanol while stirring, the temperature is controlled not to exceed 50 °C, after adding, the temperature is raised to 75 °C and reacted for 3 h, then cooled to 50 °C, neutralized with sodium hydroxide solution to a pH value of 7 - 8, n - hexane is added, after extraction and liquid separation, the organic phase is collected, and di - isooctyl phosphate is obtained by acidification and recovery;

[0044] A3. 8.3 g of intermediate A and 2.3 g of di - isooctyl phosphate are refluxed in 50 ml of toluene, 0.5 g of 4 - dimethylaminopyridine is added as a catalyst, and the reflux reaction is carried out at 120 °C for 8 h to introduce a phosphate group through transesterification reaction;

[0045] A4. Using the gradient crystallization method, first remove the unreacted substances with n - hexane, and then recrystallize with a 90Vol% ethanol solution to obtain white needle - shaped crystals, that is, the hindered phenol antioxidant.

[0046] The prepared hindered phenol antioxidant is analyzed by infrared spectroscopy, and the infrared spectrum of the hindered phenol antioxidant is as Figure 1 shown. The stretching vibration of the free phenolic hydroxyl O - H is at 3650 cm -1 , the broad peak of the hydrogen - bonded O - H is at 3350 cm -1 , the stretching vibration of the tert - butyl C - H is at 2960 - 2870 cm -1 , the characteristic peak of the triazine ring C = N is at 1590 cm -1 , the strong absorption of the phosphate P = O is at 1230 cm -1 , the out - of - plane bending vibration of the triazine ring is at 885 cm -1 . It can be seen that a triazine - ring hindered phenol antioxidant with a phosphate group is successfully synthesized.

[0047] Example 2

[0048] A preparation method of modified nano molybdenum disulfide, comprising the following steps:

[0049] B1. Disperse 5.6 g of molybdenum disulfide nanosheets in 100 ml of 95Vol% ethanol solution, ultrasonically treat for 1 - 2 h, add 10 ml of γ-aminopropyltriethoxysilane, reflux at 80 °C for 6 h, centrifuge and wash with ethanol 3 - 5 times, and vacuum dry at 60 °C to obtain amino-functionalized nano molybdenum disulfide;

[0050] B2. Ultrasonically disperse 4.5 g of amino-functionalized nano molybdenum disulfide in 100 ml of N,N-dimethylformamide for 20 - 40 min to form a stable suspension, then add 7.8 g of the hindered phenol antioxidant prepared in Example 1 and 0.5 g of N,N'-dicyclohexylcarbodiimide, heat to 60 °C under nitrogen protection, and magnetically stir and react for 24 h in the dark. After the reaction is completed, wash with N,N-dimethylformamide, tetrahydrofuran, and methanol 3 - 5 times in sequence, and vacuum dry at 50 °C to obtain modified nano molybdenum disulfide.

[0051] Example 3

[0052] A high-temperature resistant PPS material for automotive parts, comprising the following components by weight: 70 parts of PPS resin, 15 parts of modified PEEK resin, 16 parts of modified carbon fiber, 2 parts of modified nano molybdenum disulfide, 2.25 parts of magnesium hydroxide, 0.75 part of zinc borate, 0.4 part of polytetrafluoroethylene micropowder, 0.1 part of silicone composite; the modified PEEK resin is a PEEK resin with surface carboxylation treatment; the modified carbon fiber is a carbon fiber with surface amino-functionalization treatment; the modified nano molybdenum disulfide is prepared in Example 2.

[0053] The preparation method of the above high-temperature resistant PPS material for automotive parts, comprising the following steps:

[0054] S1. First, vacuum dry PPS and the modified PEEK resin at 120 °C for 6 h respectively, then add the PPS resin and the modified PEEK resin into a kneader, and knead at 280 °C for 5 min;

[0055] S2. Add the modified carbon fiber and the modified nano molybdenum disulfide, knead at 290 °C for 10 min, and finally add magnesium hydroxide, zinc borate, polytetrafluoroethylene micropowder, and silicone composite, knead at 240 °C for 2 min to obtain a mixture;

[0056] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is: zone 1 at 280 °C, zone 2 at 300 °C, zone 3 at 300 °C, zone 4 at 310 °C, zone 5 at 310 °C, zone 6 at 305 °C, the screw speed is 200 rpm, and the shear rate is 1500 s -1 ;

[0057] S4. Extrude the melt-blended material through a twin-screw extruder, perform injection molding, control the mold temperature at 140 °C, the injection pressure at 100 MPa, the holding pressure time at 15 s / mm, and then perform compression molding. First, preheat at 290 °C for 10 min, hot press at 310 °C and 10 MPa for 8 min, and finally cold press to room temperature at 100 °C and 15 MPa to obtain the high-temperature resistant PPS material for automotive parts.

[0058] Example 4

[0059] A high-temperature resistant PPS material for automotive parts, comprising the following components in parts by weight: 60 parts of PPS resin, 20 parts of modified PEEK resin, 14 parts of modified carbon fiber, 3 parts of modified nano-molybdenum disulfide, 1.5 parts of magnesium hydroxide, 0.5 part of zinc borate, 0.8 part of polytetrafluoroethylene micropowder, and 0.2 part of silicone composite; the modified PEEK resin is a PEEK resin with surface carboxylation treatment; the modified carbon fiber is a carbon fiber with surface amination treatment; the modified nano-molybdenum disulfide is prepared in Example 2.

[0060] The preparation method of the above high-temperature resistant PPS material for automotive parts comprises the following steps:

[0061] S1. First, vacuum-dry PPS and the modified PEEK resin at 120 °C for 5 h respectively, and then add the PPS resin and the modified PEEK resin into a mixer and knead at 280 °C for 8 min;

[0062] S2. Add the modified carbon fiber and the modified nano-molybdenum disulfide, knead at 290 °C for 8 min, and finally add magnesium hydroxide, zinc borate, polytetrafluoroethylene micropowder and silicone composite, and knead at 240 °C for 3 min to obtain a mixture;

[0063] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is: zone 1 at 280 °C, zone 2 at 300 °C, zone 3 at 300 °C, zone 4 at 310 °C, zone 5 at 310 °C, zone 6 at 305 °C, the screw speed is 200 rpm, and the shear rate is 1500 s -1 ;

[0064] S4. Extrude the melt-blended material through a twin-screw extruder, perform injection molding, control the mold temperature at 140 °C, the injection pressure at 90 MPa, the holding pressure time at 15 s / mm, and then perform compression molding. First, preheat at 290 °C for 10 min, hot press at 310 °C and 10 MPa for 8 min, and finally cold press to room temperature at 100 °C and 15 MPa to obtain the high-temperature resistant PPS material for automotive parts.

[0065] Example 5

[0066] A high-temperature resistant PPS material for automotive parts, comprising the following components in parts by weight: 50 parts of PPS resin, 25 parts of modified PEEK resin, 12 parts of modified carbon fiber, 4 parts of modified nano-molybdenum disulfide, 0.75 part of magnesium hydroxide, 0.25 part of zinc borate, 1.2 parts of polytetrafluoroethylene micropowder, and 0.3 part of silicone composite; the modified PEEK resin is a PEEK resin with surface carboxylation treatment; the modified carbon fiber is a carbon fiber with surface amination treatment; the modified nano-molybdenum disulfide is prepared in Example 2.

[0067] The preparation method of the above high-temperature resistant PPS material for automotive parts comprises the following steps:

[0068] S1. First, dry PPS and the modified PEEK resin in vacuum at 120°C for 4 h respectively, then add the PPS resin and the modified PEEK resin into a mixer and knead at 280°C for 10 min;

[0069] S2. Add the modified carbon fiber and the modified nano-molybdenum disulfide, knead at 290°C for 5 min, and finally add magnesium hydroxide, zinc borate, polytetrafluoroethylene micropowder and silicone composite, knead at 240°C for 4 min to obtain a mixture;

[0070] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is: zone 1 at 280°C, zone 2 at 300°C, zone 3 at 300°C, zone 4 at 310°C, zone 5 at 310°C, zone 6 at 305°C, the screw speed is 200 rpm, and the shear rate is 1500 s -1 ;

[0071] S4. Extrude the melt-blended material through the twin-screw extruder, inject and mold, control the mold temperature at 140°C, the injection pressure at 80 MPa, the holding pressure time at 15 s / mm, then press and mold, preheat at 290°C for 10 min first, hot press at 310°C and 10 MPa for 8 min, and finally cold press to room temperature at 100°C and 15 MPa to obtain the above high-temperature resistant PPS material for automotive parts.

[0072] Comparative Example 1

[0073] A high-temperature resistant PPS material for automotive parts, comprising the following components in parts by weight: 60 parts of PPS resin, 20 parts of modified PEEK resin, 3 parts of modified nano-molybdenum disulfide, 1.5 parts of magnesium hydroxide, 0.5 part of zinc borate, 0.8 part of polytetrafluoroethylene micropowder, and 0.2 part of silicone composite; the modified PEEK resin is a PEEK resin with surface carboxylation treatment; the modified nano-molybdenum disulfide is prepared in Example 2.

[0074] The preparation method of the above high-temperature resistant PPS material for automotive parts comprises the following steps:

[0075] S1. First, vacuum-dry PPS and modified PEEK resin at 120°C for 5 h respectively. Then, add the PPS resin and modified PEEK resin into a mixer and knead at 280°C for 8 min;

[0076] S2. Add modified nano-molybdenum disulfide and knead at 290°C for 8 min. Finally, add magnesium hydroxide, zinc borate, polytetrafluoroethylene micropowder and silicone complex and knead at 240°C for 3 min to obtain a mixture;

[0077] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is as follows: zone 1: 280°C, zone 2: 300°C, zone 3: 300°C, zone 4: 310°C, zone 5: 310°C, zone 6: 305°C. The screw speed is 200 rpm and the shear rate is 1500 s -1 ;

[0078] S4. Extrude the melt-blended material through the twin-screw extruder, injection mold it, control the mold temperature at 140°C, the injection pressure at 90 MPa, and the holding pressure time at 15 s / mm. Then, press it into shape. First, preheat it at 290°C for 10 min, hot press it at 310°C and 10 MPa for 8 min, and finally cold press it to room temperature at 100°C and 15 MPa to obtain the high-temperature resistant PPS material for automotive parts.

[0079] Comparative Example 2

[0080] A high-temperature resistant PPS material for automotive parts, comprising the following components in parts by weight: 60 parts of PPS resin, 20 parts of modified PEEK resin, 14 parts of modified carbon fiber, 1.5 parts of magnesium hydroxide, 0.5 part of zinc borate, 0.8 part of polytetrafluoroethylene micropowder, and 0.2 part of silicone complex; the modified PEEK resin is PEEK resin with surface carboxylation treatment; the modified carbon fiber is carbon fiber with surface amination treatment.

[0081] The preparation method of the above high-temperature resistant PPS material for automotive parts comprises the following steps:

[0082] S1. First, vacuum-dry PPS and modified PEEK resin at 120°C for 5 h respectively. Then, add the PPS resin and modified PEEK resin into a mixer and knead at 280°C for 8 min;

[0083] S2. Add modified carbon fiber and knead at 290°C for 8 min. Finally, add magnesium hydroxide, zinc borate, polytetrafluoroethylene micropowder and silicone complex and knead at 240°C for 3 min to obtain a mixture;

[0084] S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is as follows: Zone 1: 280 °C, Zone 2: 300 °C, Zone 3: 300 °C, Zone 4: 310 °C, Zone 5: 310 °C, Zone 6: 305 °C. The screw speed is 200 rpm, and the shear rate is 1500 s -1 ;

[0085] S4. Extrude the melt-blended material through the twin-screw extruder and perform injection molding. Control the mold temperature at 140 °C, the injection pressure at 90 MPa, and the holding pressure time at 15 s / mm. Then, perform compression molding. First, preheat at 290 °C for 10 min, hot press at 310 °C and 10 MPa for 8 min, and finally cold press at 100 °C and 15 MPa to room temperature to obtain the high-temperature resistant PPS material for automotive parts.

[0086] Performance Testing

[0087] I. Mechanical Property Testing

[0088] Cut the high-temperature resistant PPS materials for automotive parts in Examples 3 - 5 and Comparative Examples 1 - 2 into test specimens, and use a universal testing machine to conduct mechanical property tests. Refer to GB / T528 - 2009 to test the tensile strength of the material, refer to GB / T9341 - 2008 to test the flexural strength of the material, and refer to GB / T1043.1 - 2008 to test the impact strength of the material. The test results are shown in Table 1:

[0089] Table 1 Test Results of Mechanical Properties of High-Temperature Resistant PPS Materials for Automotive Parts

[0090]

[0091]

[0092] It can be seen from the data in Table 1 that the mechanical properties of Comparative Example 1 are significantly lower than those of other groups. Modified carbon fiber was not added in Comparative Example 1. It can be seen that the addition of modified carbon fiber significantly improves the strength of the material. The tensile strength of pure PPS resin can reach 60 - 90 MPa, the flexural strength is 90 - 140 MPa, and the notch-free impact strength is 1.1×10 2 ~9.5×10 2 kJ / m 2 . Although the mechanical properties in Comparative Example 1 are not as good as those of other groups, they are still higher than those of pure PPS resin. It can be seen that the addition of modified PEEK resin and modified nano-molybdenum disulfide also has a certain improvement effect on the mechanical properties of PPS resin.

[0093] II. Thermal Stability Performance Testing

[0094] The high-temperature resistant PPS materials for automotive parts prepared in Examples 3 to 5 and Comparative Examples 1 to 2 were aged at 200 °C for 24 h, 48 h, and 72 h respectively, and then their tensile strengths were tested. The tensile strength test was carried out with reference to GB / T 528-2009. The molded specimens were cut into dumbbell-shaped tensile splines with a size of 25 mm × 4 mm, and the tensile rate was 20 mm / min. The tensile strength retention rate was calculated by comparing with the initial tensile strength, and the data obtained are shown in Table 2.

[0095] Table 2 Test results of thermal stability of high-temperature resistant PPS materials for automotive parts

[0096]

[0097]

[0098] It can be seen from the data in Table 2 that the thermal stability of the high-temperature resistant PPS material for automotive parts prepared in Comparative Example 2 is worse than that of other groups. Modified nano-molybdenum disulfide was not added in Comparative Example 2. The modified nano-molybdenum disulfide in the present invention is graft-modified with a hindered phenol antioxidant. Nano-molybdenum disulfide itself can endow the polymer material with wear resistance and self-lubricity. By using the nano-synergistic effect, the migration rate of the hindered phenol antioxidant is reduced, and a slow-release effect can be achieved, so that the material has a lasting anti-thermal oxidation ability. The hindered phenol antioxidant provides a rigid planar structure with a triazine core to inhibit molecular thermal motion. The antioxidant efficiency of the multi-site hindered phenol structure is higher than that of traditional antioxidants. The phosphate group can capture the free radicals generated by the degradation of PPS, further improving the antioxidant effect.

[0099] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0100] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A high-temperature resistant PPS material for automotive parts, characterized in that, It comprises the following components in parts by weight: 50 - 70 parts of PPS resin, 15 - 25 parts of modified PEEK resin, 12 - 16 parts of modified carbon fiber, 2 - 4 parts of modified nano molybdenum disulfide, 1 - 3 parts of flame retardant, and 0.5 - 1.5 parts of lubricant; The modified PEEK resin is a PEEK resin with surface carboxylation treatment; The modified carbon fiber is a carbon fiber with surface amination treatment; The modified nano molybdenum disulfide is nano molybdenum disulfide surface modified by a silane coupling agent and then grafted with a hindered phenol antioxidant through in-situ polymerization. The hindered phenol antioxidant is a triazine ring hindered phenol antioxidant, and its structural formula is as follows:

2. The high-temperature resistant PPS material for automotive parts according to claim 1, characterized in that, The flame retardant is a mixture of magnesium hydroxide and zinc borate in a mass ratio of 3:

1.

3. The high-temperature resistant PPS material for automotive parts according to claim 1, characterized in that, The lubricant is a mixture of polytetrafluoroethylene micropowder and silicone complex in a mass ratio of 4:

1.

4. The high-temperature resistant PPS material for automotive parts according to claim 1, characterized in that, The modified PEEK resin is prepared by a chemical oxidation method, a plasma treatment method, an ultraviolet ozone treatment method or a bioenzyme catalysis method.

5. A high-temperature resistant PPS material for automotive parts according to claim 1, characterized in that, The modified carbon fiber is prepared by surface modification with γ-aminopropyltriethoxysilane.

6. The high-temperature resistant PPS material for automotive parts according to claim 1, characterized in that, The preparation method of the hindered phenol antioxidant comprises the following steps: A1. Under nitrogen protection, cyanuric chloride and 3,5-di-tert-butyl-4-hydroxybenzoic acid are reacted in tetrahydrofuran, and Na2CO3 is added as an acid-binding agent, and the reaction is carried out at 55 - 70 °C for 10 - 12 h to obtain intermediate A; A2. Phosphorus pentoxide is added to isooctanol with stirring at room temperature, and the temperature is controlled not to exceed 50 °C. After adding, the temperature is raised to 70 - 80 °C and the reaction is carried out for 2 - 3 h, then the temperature is lowered to 45 - 50 °C, and it is neutralized to pH 7 - 8 with sodium hydroxide solution. N-hexane is added, and the organic phase is collected after extraction and separation, and diisooctyl phosphate is obtained by acidification and recovery; A3. Intermediate A and diisooctyl phosphate are refluxed in toluene, and 4-dimethylaminopyridine is added as a catalyst, and the reflux reaction is carried out at 120 °C for 4 - 8 h to introduce a phosphate group through an ester exchange reaction; A4. The gradient crystallization method is adopted. First, the unreacted substances are removed with n-hexane, and then recrystallized with a 90Vol% ethanol solution to obtain white needle-like crystals, that is, the hindered phenol antioxidant.

7. The high-temperature resistant PPS material for automotive parts according to claim 6, wherein In step A1, the molar ratio of cyanuric chloride to 3,5-di-tert-butyl-4-hydroxybenzoic acid is 1:

3.

8. The high-temperature resistant PPS material for automotive parts according to claim 6, wherein In step A3, the molar ratio of intermediate A to diisooctyl phosphate is 1:1.

2.

9. The high-temperature resistant PPS material for automotive parts according to claim 1, wherein The preparation method of the modified nano molybdenum disulfide comprises the following steps: B1. Molybdenum disulfide nanosheets are dispersed in a 95Vol% ethanol solution, ultrasonically treated for 1 - 2 h, γ-aminopropyltriethoxysilane is added, and the reflux reaction is carried out at 80 °C for 4 - 8 h. After centrifugation, it is washed with ethanol 3 - 5 times and vacuum dried at 60 °C to obtain aminated nano molybdenum disulfide; B2. The aminated nano molybdenum disulfide is ultrasonically dispersed in N,N-dimethylformamide for 20 - 40 min to form a stable suspension, and then the hindered phenol antioxidant and N,N'-dicyclohexylcarbodiimide are added. Under nitrogen protection, the temperature is raised to 60 °C, and the magnetic stirring reaction is carried out for 20 - 24 h in the dark. After the reaction is completed, it is washed with N,N-dimethylformamide, tetrahydrofuran, and methanol 3 - 5 times respectively, and vacuum dried at 50 °C to obtain the modified nano molybdenum disulfide.

10. A preparation method of a high-temperature resistant PPS material for automotive parts as described in any one of claims 1 to 9, characterized in that, It comprises the following steps: S1. First, dry PPS and modified PEEK resin in vacuum at 120°C for 4 - 6 h respectively. Then, add PPS resin and modified PEEK resin into a mixer and knead at 280°C for 5 - 10 min; S2. Add modified carbon fiber and modified nano - molybdenum disulfide, knead at 290°C for 5 - 10 min. Finally, add a flame retardant and a lubricant, knead at 240°C for 2 - 4 min to obtain a mixture; S3. Add the mixture into a twin-screw extruder for melt blending. The temperature gradient of the twin-screw extruder is as follows: zone 1: 280 °C, zone 2: 300 °C, zone 3: 300 °C, zone 4: 310 °C, zone 5: 310 °C, zone 6: 305 °C. The screw speed is 200 rpm and the shear rate is 1500 s -1 ; S4. Extrude the melt - blended material through a twin - screw extruder, inject - mold it, control the mold temperature at 140°C, injection pressure at 80 - 100 MPa, holding pressure time at 15 s / mm. Then, press - mold it. First, pre - heat at 290°C for 8 - 10 min, hot - press at 310°C and 10 MPa for 6 - 8 min, and finally cold - press to room temperature at 100°C and 15 MPa to obtain the high - temperature - resistant PPS material for automotive parts.

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