High-heat-resistance PPS protective material and preparation process thereof

Abstract

The invention relates to a high-heat-resistance PPS protective material and a preparation process thereof. The protection material is prepared from the following components in parts by weight: PPS resin, modified glass fiber, surface modified boron nitride, element doped modified silicon carbide, an ABS-g-MAH and POE-g-MAH compound, nano aluminum oxide, an antioxidant, an interface modifier and a synergistic stabilizer in a specific proportion. Wherein the modified glass fiber is prepared by reacting glass fiber with an ethanol solution, potassium hydroxide and the like; the surface modified boron nitride is obtained by treating nano boron nitride, a sodium hydroxide solution and the like; the element-doped modified silicon carbide is prepared by reacting silicon carbide powder with nano titanium powder and the like. The preparation process sequentially comprises the following steps: carrying out ultrasonic pretreatment and vacuum drying to obtain a mixture 1, mixing by a high-speed mixer to obtain a mixture 2, carrying out extrusion granulation and vacuum devolatilization by a twin-screw extruder, carrying out water-cooling granulation, drying to obtain granules, preparing a standard sample through injection molding, testing the performance and the like, wherein each step has corresponding specific parameters. The material has high heat resistance, the heat distortion temperature can reach 280 DEG C or above, and the material can be used as a protection material in the field needing high heat resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a high-heat-resistant polyphenylene sulfide (PPS) protective material and a preparation method thereof. Background Art

[0002] Polyphenylene sulfide (PPS) is a high-performance thermoplastic resin with excellent high-temperature resistance, chemical resistance, flame retardancy, and dimensional stability. However, pure PPS materials suffer from insufficient rigidity and low impact toughness, which limit their application in extreme environments. Existing technologies can partially improve performance by adding glass fiber, inorganic fillers, or elastomer modifications, but the improvement in heat resistance is limited, and insufficient interfacial compatibility between the material and the matrix can easily lead to performance degradation. Traditional PPS materials still have certain limitations in high-temperature environments, such as insufficient thermal stability and decreased mechanical properties. Therefore, the development of a highly heat-resistant PPS protective material is of great practical significance. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a high-heat-resistant PPS protective material and its preparation process. Through component optimization and process improvement, the stability, mechanical strength and chemical corrosion resistance of the material in high-temperature environments are significantly improved, making it suitable for protection and insulation under extreme working conditions.

[0004] Technical solution: A high-heat-resistant PPS protective material, comprising, by weight: 60-70 parts of PPS resin, 15-20 parts of modified glass fiber, 10-15 parts of surface-modified boron nitride, 2-3 parts of element-doped modified silicon carbide, 3-5 parts of ABS-g-MAH and POE-g-MAH compound, 3-5 parts of nano-alumina, 0.5-1.5 parts of antioxidant, 0.5-1 part of interface modifier, and 3-4 parts of synergistic stabilizer; The preparation method of the modified glass fiber comprises the following steps: adding glass fiber to a reaction bottle, adding an ethanol solution twice the weight of the glass fiber, adding potassium hydroxide 0.2 times the weight of the ethanol under stirring, heating and refluxing for 0.5 h, filtering, rinsing with ethanol, drying under vacuum at 50° C. to constant weight, adding nano-calcium carbonate 0.2 times the weight of the glass fiber, stirring and mixing uniformly, and obtaining the modified glass fiber; The surface-modified boron nitride is prepared by adding nano-boron nitride to a 10M sodium hydroxide solution having a weight that is 10 times that of the nano-boron nitride, heating and refluxing for 5 hours, filtering, heating the filter cake to 800°C at a rate of 10°C / min under argon protection and maintaining the temperature for 3 hours, then introducing a mixed gas of ammonia vapor and argon at a ratio of 1:10 (V / V) at a flow rate of 1 ml / min, cooling the temperature to 500°C at a rate of 2°C / min, and then naturally cooling the filter cake to room temperature. The preparation method of the element-doped modified silicon carbide is as follows: silicon carbide powder is mixed with nano-titanium powder whose weight is 5% of the weight of the silicon carbide powder, and then placed in a crucible, heated to 900°C and reacted under vacuum conditions for 3 hours, then air is introduced and heated to 1000°C and reacted for 2 hours, cooled to room temperature, and mixed with copper nitride whose weight is 3% of the weight of the silicon carbide powder in a three-dimensional mixer for 30 minutes to obtain the obtained product.

[0005] Preferably, the mass ratio of ABS-g-MAH to POE-g-MAH in the compound of ABS-g-MAH and POE-g-MAH is 2:1.

[0006] Preferably, the antioxidant is a compound of triphenyl phosphite and pentaerythritol tetrakis-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and the mass ratio of triphenyl phosphite to pentaerythritol tetrakis-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 1:1.

[0007] Preferably, the interface modifier is any one of silane coupling agent KH-550 or titanate coupling agent.

[0008] Preferably, the synergistic stabilizer is 2-5 parts of cerium oxide and 1-5 parts of polytetrafluoroethylene (PTFE) powder.

[0009] A preparation process of a high heat-resistant PPS protective material comprises the following steps: (1) The modified glass fiber, surface-modified boron nitride, element-doped modified silicon carbide, nano-aluminum oxide and interface modifier are ultrasonically pretreated in an ethanol solution, filtered and vacuum-dried to obtain a mixture 1; (2) adding the mixture 1 obtained in step (1) and the PPS resin, antioxidant, interfacial modifier, and synergistic stabilizer into a high-speed mixer to obtain a mixture 2; (3) The mixture 2 obtained in step (2) is extruded into granules through a twin-screw extruder and vacuum devolatilized; (4) After water cooling and pelletizing, vacuum drying was performed at 80°C for 4 hours to obtain pellets.

[0010] Preferably, in step (1), the weight of ethanol is twice the total weight of the modified glass fiber, surface-modified boron nitride, element-doped modified silicon carbide, and nano-alumina, the ultrasonic frequency is 40 kHz, the ultrasonic time is 20 min, and the product is dried at 40° C. in a vacuum oven.

[0011] Preferably, in step (2), the mixing in the high-speed mixer is carried out at 110-120° C. for 10-15 minutes.

[0012] Preferably, in step (3), the extrusion granulation parameters of the twin-screw extruder are: zone 1 180-200°C, zone 2 200-210°C, zone 3 210-220°C, zone 4 220-230°C, screw speed 300-400 rpm, vacuum devolatilization degree of -0.095±0.003MPa, and devolatilization time 30s. Beneficial effects

[0013] 1. The glass fiber reacts with potassium hydroxide to generate potassium silicate on the surface of the glass fiber and introduce some hydroxyl groups, which are then mixed with calcium carbonate. The calcium carbonate is bonded to the surface of the glass fiber by potassium silicate. If high heat is applied and ignited, the silica in the glass fiber will react with the calcium carbonate, releasing carbon dioxide, which plays a flame retardant role. At the same time, the introduced hydroxyl groups can form hydrogen bonds with the sulfur in PPS, increasing the bonding strength between the glass fiber and PPS.

[0014] 2. Nano-boron nitride was added to a 10M sodium hydroxide solution to introduce hydroxyl groups. Ammonia vapor was then introduced for natural annealing to introduce amino groups. The introduced amino and hydroxyl groups can form hydrogen bonds with the sulfur in PPS, increasing the binding strength. The nitrogen atom of the amino group is electronegative and can form electrostatic interactions with the oxygen vacancies in cerium oxide. Although this interaction is not a typical complexation, it can also enhance the binding of the amino group to cerium oxide to a certain extent. At the same time, the amino group (-NH2) forms hydrogen bonds or covalent bonds with the hydroxyl groups on the surface of the boron nitride, and the hydroxyl groups of the boron nitride further interact with the hydroxyl groups on the surface of cerium oxide, forming an "amino-boron nitride-hydroxyl-cerium oxide" interfacial bridging structure. In strongly alkaline or oxidizing environments, the interfacial bridging structure can slow the corrosion or dissolution of cerium oxide, extending the life of the material. The high surface area and chemical inertness of boron nitride prevent cerium oxide particle agglomeration. At the same time, its layered structure may buffer external stress and improve the mechanical stability of the overall material.

[0015] 3. Silicon carbide powder is mixed with nano-titanium powder and placed in a crucible. At high temperature, titanium combines with carbon in silicon carbide to form titanium carbide. Titanium carbide has a high hardness, high melting point, and excellent chemical stability. Air is then introduced to the surface to heat the surface, introducing silicon oxide and titanium oxide. The adhesion of titanium dioxide and silicon dioxide can improve the dispersion of silicon carbide, making it more evenly distributed in the composite material, thereby improving the overall performance of the material. The adhesion of titanium dioxide and silicon dioxide can also increase the hardness and wear resistance of the silicon carbide surface. The modified silicon carbide surface has higher thermal shock resistance and can maintain good performance in high temperature environments. At the same time, the adhesion of titanium dioxide and silicon dioxide can improve the interfacial compatibility of silicon carbide with polymer matrices or other materials, thereby improving the mechanical properties of the composite material. Mixed with copper nitride, the copper nitride decomposes upon heating, producing copper and nitrogen. While the nitrogen is flame retardant, the copper absorbs oxygen to form copper oxide, thereby reducing the oxygen concentration on the surface of the material and further retardant it. At the same time, the generated copper oxide also reacts with the carbon generated by combustion to produce carbon dioxide and copper, forming a flame retardant cycle.

[0016] 4. An ABS-g-MAH / POE-g-MAH mixture (2:1) is used as a compatibilizer. While enhancing toughness, it also improves melt flow through the reaction of maleic anhydride groups with PPS end groups, ensuring processing stability in highly filled systems. A compound antioxidant (phosphite + phenol) and a synergistic stabilizer (cerium oxide + PTFE) are used to inhibit high-temperature oxidative degradation and extend the material's service life. The oxygen vacancy defects in the cerium oxide can capture free radicals, while the PTFE micropowder reduces frictional heat accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 3 is a field emission scanning electron microscope comparison diagram of the modified glass fiber of the present invention and the glass fiber before modification; wherein A is the modified glass fiber of the present invention, and B is the glass fiber before modification.

[0018] Figure 2 This is a field emission scanning electron microscope comparison diagram of the surface-modified boron nitride of the present invention and the boron nitride before modification; wherein A is the modified boron nitride of the present invention, and B is the boron nitride before modification.

[0019] Figure 3 The figure shows the absorption spectra of the surface-modified boron nitride of the present invention and the boron nitride before modification under ultraviolet-visible light.

[0020] Figure 4 This is a field emission scanning electron microscope comparison of the element-doped modified silicon carbide of the present invention and the silicon carbide before modification; wherein A is the element-doped modified silicon carbide of the present invention, and B is the silicon carbide before modification. DETAILED DESCRIPTION

[0021] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0022] Preparation of modified glass fiber: Add glass fiber to a reaction bottle, add ethanol solution twice the weight of the glass fiber, add potassium hydroxide 0.2 times the weight of the ethanol under stirring, heat and reflux for 0.5h, filter, rinse with ethanol, vacuum dry at 50℃ to constant weight, add nano calcium carbonate 0.2 times the weight of the glass fiber, stir and mix evenly to obtain the modified glass fiber; the field emission scanning electron microscope comparison of the modified glass fiber and the unmodified glass fiber is shown in the attached figure Figure 1 .

[0023] Preparation of surface-modified boron nitride: Add nano-boron nitride to a 10M sodium hydroxide solution with a weight 10 times that of the nano-boron nitride, heat and reflux for 5 hours, filter, and heat the filter cake to 800°C at a rate of 10°C / min under argon protection and keep warm for 3 hours. Then, introduce a mixed gas of ammonia vapor: argon = 1:10 (V / V) at a flow rate of 1 ml / min, reduce the temperature to 500°C at a rate of 2°C / min, and then naturally cool to room temperature to obtain the surface-modified boron nitride. The field emission scanning electron microscopy comparison of the surface-modified boron nitride of the present invention and the boron nitride before modification is shown in the attached figure. Figure 2 The absorption spectra of the surface modified boron nitride of the present invention and the boron nitride before modification under ultraviolet-visible light are shown in the attached Figure 3 .

[0024] Preparation of element-doped modified silicon carbide: Silicon carbide powder is mixed with nano-titanium powder (5% by weight of the silicon carbide powder) and placed in a crucible, heated to 900°C for reaction under vacuum conditions for 3 hours, then heated to 1000°C for reaction for 2 hours after passing air, cooled to room temperature, and mixed with copper nitride (3% by weight of the silicon carbide powder) in a three-dimensional mixer for 30 minutes to obtain the obtained product; the field emission scanning electron microscopy comparison of the element-doped modified silicon carbide of the present invention and the silicon carbide before modification is shown in the attached figure. Figure 4 .

[0025] Formula (parts by weight): PPS resin: 65 parts Modified glass fiber: 18 parts Surface modified boron nitride: 12 parts Element-doped modified silicon carbide: 2.5 parts ABS-g-MAH / POE-g-MAH compound: 4 parts (mass ratio 2:1) Nano-alumina: 4 parts Antioxidant: 1 part (triphenyl phosphite: pentaerythritol tetra-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate = 1:1) Interface modifier: 0.8 parts (KH-550) Synergistic stabilizer: 3.5 parts (3 parts cerium oxide + 1 part PTFE powder) Preparation process: (1) 180 g of modified glass fiber, 120 g of surface-modified boron nitride, 25 g of element-doped modified silicon carbide, 40 g of nano-alumina, and 8 g of KH-550 interfacial modifier were pretreated in 746 g of anhydrous ethanol solution by 40 kHz ultrasonic treatment for 20 min, filtered, and dried at 40° C. in a vacuum oven to obtain a mixture 1; (2) The mixture 1 obtained in step (1) was added with 650 g of PPS resin, 10 g of antioxidant (5 g of triphenyl phosphite + 5 g of pentaerythritol tetra-β-propionate) and 35 g of synergistic stabilizer (30 g of cerium oxide + 5 g of PTFE micropowder) in a high-speed mixer and mixed at 115° C. for 12 min to obtain mixture 2; (3) The mixture 2 obtained in step (2) was extruded into granules through a twin-screw extruder. The twin-screw extruder had the following temperatures: zone 1 190°C, zone 2 205°C, zone 3 215°C, zone 4 225°C, screw speed 350 rpm, vacuum degree -0.092 MPa, and devolatilization for 30 s; (4) After water cooling and pelletizing, vacuum drying was performed at 80°C for 4 hours to obtain pellets. Example

[0026] Preparation of modified glass fiber: Add glass fiber to a reaction flask, add an ethanol solution twice the weight of the glass fiber, add potassium hydroxide 0.2 times the weight of the ethanol while stirring, heat and reflux for 0.5h, filter, rinse with ethanol, dry under vacuum at 50°C to constant weight, add nano calcium carbonate 0.2 times the weight of the glass fiber, stir and mix evenly to obtain the modified glass fiber. Preparation of surface-modified boron nitride: Add nano-boron nitride to a 10M sodium hydroxide solution with a weight 10 times that of the nano-boron nitride, heat under reflux for 5 hours, filter, and heat the filter cake to 800°C at a rate of 10°C / min under argon protection and keep warm for 3 hours. Then, introduce a mixed gas of ammonia vapor: argon = 1:10 (V / V) at a flow rate of 1 ml / min, reduce the temperature to 500°C at a rate of 2°C / min, and then naturally cool to room temperature to obtain the product; Preparation of element-doped modified silicon carbide: Silicon carbide powder is mixed with nano-titanium powder whose weight is 5% of the weight of silicon carbide powder and placed in a crucible, heated to 900°C and reacted under vacuum conditions for 3 hours, then air is introduced and heated to 1000°C and reacted for 2 hours, cooled to room temperature, and mixed with copper nitride whose weight is 3% of the weight of silicon carbide powder in a three-dimensional mixer for 30 minutes.

[0027] Formula (parts by weight): PPS resin: 60 parts Modified glass fiber: 15 parts Surface modified boron nitride: 10 parts Element-doped modified silicon carbide: 2 parts 3 parts of ABS-g-MAH / POE-g-MAH compound (mass ratio 2:1) Nano-alumina: 3 parts Antioxidant: 0.5 parts (triphenyl phosphite: pentaerythritol tetra-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate = 1:1) Interface modifier: 0.5 parts (KH-550) Synergistic stabilizer: 3 parts (2 parts cerium oxide + 1 part PTFE powder) Preparation process: (1) 150 g of modified glass fiber, 100 g of surface-modified boron nitride, 20 g of element-doped modified silicon carbide, 30 g of nano-alumina and 5 g of KH-550 interface modifier were pretreated in 610 g of anhydrous ethanol solution by 40 kHz ultrasonic treatment for 20 min, filtered and dried in vacuum at 40°C to obtain a mixture 1; (2) The mixture 1 obtained in step (1) was added to 600 g of PPS resin, 5 g of antioxidant (2.5 g of triphenyl phosphite + 2.5 g of pentaerythritol tetra-β-propionate) and 30 g of synergistic stabilizer (20 g of cerium oxide + 10 g of PTFE micropowder) in a high-speed mixer and mixed at 110° C. for 15 min to obtain mixture 2; (3) The mixture 2 obtained in step (2) was extruded into granules through a twin-screw extruder. The twin-screw extruder had the following conditions: zone 1 180°C, zone 2 200°C, zone 3 210°C, zone 4 220°C, screw speed 300 rpm, vacuum degree -0.095 MPa, and devolatilization for 30 s; (4) After water cooling and pelletizing, vacuum drying was performed at 80°C for 4 hours to obtain pellets. Example

[0028] Preparation of modified glass fiber: Add glass fiber to a reaction flask, add an ethanol solution twice the weight of the glass fiber, add potassium hydroxide 0.2 times the weight of the ethanol while stirring, heat and reflux for 0.5h, filter, rinse with ethanol, dry under vacuum at 50°C to constant weight, add nano calcium carbonate 0.2 times the weight of the glass fiber, stir and mix evenly to obtain the modified glass fiber. Preparation of surface-modified boron nitride: Add nano-boron nitride to a 10M sodium hydroxide solution with a weight 10 times that of the nano-boron nitride, heat under reflux for 5 hours, filter, and heat the filter cake to 800°C at a rate of 10°C / min under argon protection and keep warm for 3 hours. Then, introduce a mixed gas of ammonia vapor: argon = 1:10 (V / V) at a flow rate of 1 ml / min, reduce the temperature to 500°C at a rate of 2°C / min, and then naturally cool to room temperature to obtain the product; Preparation of element-doped modified silicon carbide: Silicon carbide powder is mixed with nano-titanium powder whose weight is 5% of the weight of silicon carbide powder and placed in a crucible, heated to 900°C and reacted under vacuum conditions for 3 hours, then air is introduced and heated to 1000°C and reacted for 2 hours, cooled to room temperature, and mixed with copper nitride whose weight is 3% of the weight of silicon carbide powder in a three-dimensional mixer for 30 minutes.

[0029] Formula (parts by weight): PPS resin: 70 parts Modified glass fiber: 20 parts Surface modified boron nitride: 15 parts Element-doped modified silicon carbide: 3 parts 5 parts of ABS-g-MAH / POE-g-MAH compound (mass ratio 2:1) Nano-alumina: 5 parts Antioxidant: 1.5 parts (triphenyl phosphite: pentaerythritol tetra-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate = 1:1) Interface modifier: 1 part (KH-550) Synergistic stabilizer: 4 parts (2 parts cerium oxide + 2 parts PTFE powder) Preparation process: (1) 200 g of modified glass fiber, 150 g of surface-modified boron nitride, 30 g of element-doped modified silicon carbide, 50 g of nano-alumina and 10 g of KH-550 interface modifier were pretreated in 880 g of anhydrous ethanol solution by 40 kHz ultrasonic treatment for 20 min, filtered and dried in vacuum at 40°C to obtain a mixture 1; (2) The mixture 1 obtained in step (1) was added to 700 g of PPS resin, 15 g of antioxidant (7.5 g of triphenyl phosphite + 7.5 g of pentaerythritol tetra-β-propionate) and 40 g of synergistic stabilizer (20 g of cerium oxide + 20 g of PTFE micropowder) in a high-speed mixer and mixed at 120° C. for 10 min to obtain mixture 2; (3) The mixture 2 obtained in step (2) was extruded into granules through a twin-screw extruder. The twin-screw extruder was set at: 200°C in zone 1, 210°C in zone 2, 220°C in zone 3, and 230°C in zone 4, with a screw speed of 400 rpm and a vacuum degree of -0.098 MPa for devolatilization for 30 seconds. (4) After water cooling and pelletizing, vacuum drying was performed at 80°C for 4 hours to obtain pellets.

[0030] The same as Example 1, except that the glass fiber, boron nitride, and silicon carbide are all unmodified raw materials, the synergistic stabilizer (cerium oxide + PTFE) is eliminated, and the compound compatibilizer is replaced by a single ABS-g-MAH.

[0031] Same as Example 1, except that untreated glass fiber is used instead of modified glass fiber.

[0032] Same as Example 1, except that the surface-modified boron nitride is replaced by unmodified nano-boron nitride.

[0033] Same as Example 1, except that original silicon carbide powder is used to replace element-doped modified silicon carbide.

[0034] The same as Example 1, except that the ABS-g-MAH and POE-g-MAH compound and the synergistic stabilizer are omitted.

[0035] 5±0.1 mg of pellets were ground through a 200-mesh sieve and evenly spread on the bottom of a crucible. In a high-purity N2 (99.999%) atmosphere with a flow rate of 50 mL / min, the temperature was increased at 10°C / min from 50°C to 800°C. Three replicates were prepared in each group, and the temperature difference was valid within ±2°C. High-temperature stability test (TGA) was performed to obtain the corresponding onset decomposition temperature and residual carbon rate at 800°C. The material was injection-molded into standard specimens (Type I tensile bar: 165×13×3 mm³; bending bar: 80×10×4 mm³). After preheating in an oven at 200°C for 30 min, the corresponding mechanical strength test (ASTM D638 / D790) was immediately performed. The tensile strength clamp spacing was 115 mm, the speed was 50 mm / min, and the bending strength span was 64 mm, the speed was 2 mm / min. The corresponding tensile strength and bending strength test data were obtained. The polished specimens (50×25×3 The specimens were completely immersed in 98% sulfuric acid etching solution (liquid level ≥ 20 mm), sealed and placed in a dark place for 24 hours. After removal, they were rinsed with running water for 1 minute, ultrasonicated in anhydrous ethanol for 5 minutes, and vacuum-dried at 80°C for 4 hours. Five specimens were weighed per group, and outliers (mass change of more than ±15%) were eliminated. The tensile strength and mass loss rate after corrosion were measured according to ASTM D638. The specimens were fixed vertically in a combustion chamber. Starting from 23% O2, the oxygen concentration was adjusted in 0.5% steps to test the LOI value (the lowest oxygen concentration that does not self-extinguish after three consecutive combustions). The specimens were fixed vertically, and the flame of a Bunsen burner (20 mm high) was brought into contact with the lower end for 10 seconds. The first self-extinguishing time t1 after the flame was removed was recorded, and the second ignition time t1 was recorded for 10 seconds. Record t2 and whether the absorbent cotton ignites. Conduct UL94 testing using the following rating criteria: V-0, t1+t2≤10s, no ignition; V-1, t1+t2≤30s, no ignition; V-2, t1+t2≤30s, ignition. UL94 specimen thickness is 3.0±0.2mm. Specimens are hung in an oven at 180°C (spacing ≥20mm) with forced hot air circulation (wind speed 1m / s). Remove after 100 hours and rotate every 24 hours to ensure uniform heating. After cooling to room temperature, tensile strength is tested according to ASTM D638, and surface cracks are observed visually or through a 20x magnifying glass to determine the corresponding high-temperature oxidation stability data.

[0036] Table 1 Test results of examples and comparative examples It can be seen from the examples that the initial decomposition temperature of the examples exceeds 485°C, and the residual carbon rate at 800°C is higher than 58%, which is 13%-30% higher than that of comparative example 1. This shows that the modified glass fiber, boron nitride and silicon carbide and other components work synergistically to greatly enhance the thermal stability of the material; the tensile strength of the examples at 200°C exceeds 80 MPa, and the flexural strength exceeds 112 MPa, which is 20%-40% higher than that of comparative example 2, which shows that surface-modified boron nitride and element-doped modified silicon carbide play an important role in enhancing the high-temperature mechanical properties of the material; the LOI value of the examples reaches more than 36%, and the UL94 grade reaches V-0. Compared with Comparative Example 2, the flame retardant performance is improved by 40%-50%, indicating that the flame retardant mechanisms of the modified glass fiber and element-doped modified silicon carbide work together to achieve efficient flame retardancy. In a 98% sulfuric acid corrosion environment, the mass loss rate of the example is controlled within 1.5%, a decrease of 70%-80% compared with Comparative Example 4, indicating that the ceramic layer formed by the element-doped modified silicon carbide effectively improves the corrosion resistance of the material. After aging at 180°C for 100 hours, the tensile strength retention rate of the example exceeds 78%, and there are no surface cracks, which is a 40%-50% improvement compared with Comparative Example 5, indicating that the compounded compatibilizer and stabilizer significantly improve the long-term thermal stability of the material. Through component boundary effect analysis, Example 3 (high filler / PPS resin formula) exhibits the best overall performance and is particularly suitable for extremely high-temperature conditions.

[0037] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A high heat-resistant PPS protective material, characterized in that: The composition comprises, by weight: 60-70 parts of PPS resin, 15-20 parts of modified glass fiber, 10-15 parts of surface-modified boron nitride, 2-3 parts of element-doped modified silicon carbide, 3-5 parts of ABS-g-MAH and POE-g-MAH compound, 3-5 parts of nano-alumina, 0.5-1.5 parts of antioxidant, 0.5-1 parts of interface modifier and 3-4 parts of synergistic stabilizer. The preparation method of the modified glass fiber comprises the following steps: adding glass fiber to a reaction bottle, adding an ethanol solution twice the weight of the glass fiber, adding potassium hydroxide 0.2 times the weight of the ethanol under stirring, heating and refluxing for 0.5 h, filtering, rinsing with ethanol, drying under vacuum at 50° C. to constant weight, adding nano-calcium carbonate 0.2 times the weight of the glass fiber, stirring and mixing uniformly, and obtaining the modified glass fiber; The surface-modified boron nitride is prepared by adding nano-boron nitride to a 10M sodium hydroxide solution having a weight that is 10 times that of the nano-boron nitride, heating and refluxing for 5 hours, filtering, heating the filter cake to 800°C at a rate of 10°C / min under argon protection and maintaining the temperature for 3 hours, then introducing a mixed gas having a volume ratio of ammonia vapor to argon gas of 1:10 at a flow rate of 1 ml / min, cooling the temperature to 500°C at a rate of 2°C / min, and then naturally cooling the filter cake to room temperature. The preparation method of the element-doped modified silicon carbide is as follows: silicon carbide powder is mixed with nano-titanium powder whose weight is 5% of the weight of the silicon carbide powder, and then placed in a crucible, heated to 900°C and reacted under vacuum conditions for 3 hours, then air is introduced and heated to 1000°C and reacted for 2 hours, cooled to room temperature, and mixed with copper nitride whose weight is 3% of the weight of the silicon carbide powder in a three-dimensional mixer for 30 minutes to obtain the obtained product.

2. The high heat-resistant PPS protective material according to claim 1, characterized in that: In the composite of ABS-g-MAH and POE-g-MAH, the mass ratio of ABS-g-MAH to POE-g-MAH is 2:

1.

3. The high heat-resistant PPS protective material according to claim 1, characterized in that: The antioxidant is a compound of triphenyl phosphite and pentaerythritol tetrakis-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and the mass ratio of triphenyl phosphite to pentaerythritol tetrakis-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 1:

1.

4. The high heat-resistant PPS protective material according to claim 1, characterized in that: The interface modifier is any one of silane coupling agent KH-550 or titanate coupling agent.

5. The high heat-resistant PPS protective material according to claim 1, characterized in that: The synergistic stabilizer is 2-5 parts of cerium oxide and 1-5 parts of polytetrafluoroethylene powder.

6. A process for preparing the high heat-resistant PPS protective material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, ultrasonically pretreating the modified glass fiber, surface-modified boron nitride, element-doped modified silicon carbide, nano-aluminum oxide, and the interface modifier in an ethanol solution, filtering, and vacuum drying to obtain a mixture 1; Improve the interfacial bonding strength with PPS and enhance dispersibility; S2, adding the mixture 1 obtained in step S1, PPS resin, antioxidant, interfacial modifier, and synergistic stabilizer into a high-speed mixer to obtain mixture 2; S3, the mixture 2 obtained in step S2 is extruded into granules through a twin-screw extruder, and vacuum devolatilized; S4. After water-cooling and pelletizing, vacuum drying is performed at 80°C for 4 hours to obtain pellets; standard specimens are prepared by injection molding, and the heat deformation temperature is tested to be above 280°C under a pressure of 1.8 MPa.

7. The preparation process of the high heat-resistant PPS protective material according to claim 6, characterized in that: In step S1, the weight of ethanol is twice the total weight of the modified glass fiber, surface-modified boron nitride, element-doped modified silicon carbide, and nano-alumina, the ultrasonic frequency is 40 kHz, the ultrasonic time is 20 min, and the product is dried at 40° C. in a vacuum.

8. The preparation process of the high heat-resistant PPS protective material according to claim 6, characterized in that: In step S2, the high-speed mixer mixes the materials at 110-120° C. for 10-15 minutes.

9. The preparation process of the high heat-resistant PPS protective material according to claim 6, characterized in that: In step S3, the extrusion granulation parameters of the twin-screw extruder are: zone 1 180-200°C, zone 2 200-210°C, zone 3 210-220°C, zone 4 220-230°C, screw speed 300-400 rpm, vacuum devolatilization degree of -0.095±0.003 MPa, and devolatilization time 30 s.

Images