Preparation method of polyphenylene sulfide composite material

Abstract

The invention discloses a preparation method of a polyphenylene sulfide composite material, and relates to the technical field of polyphenylene sulfide composite materials. According to the preparation method of the polyphenylene sulfide composite material, a response outer layer-smoke suppression interlayer-heat insulation core layer-supporting bottom layer four-dimensional protection system is constructed, under the fire disaster condition, an MXene sheet layer in the response outer layer and UiO-66 crystals achieve the synergistic effect, a compact carbon layer is formed to block heat transfer, CsPbBr3 quantum dots in the smoke suppression interlayer capture combustion free radicals and adsorb smoke particles, and therefore the smoke suppression effect is achieved. The carbon fibers in the heat insulation core layer are directionally arranged to form an efficient thermal resistance network, the limit oxygen index of the material is effectively improved, the smoke density grade is reduced, the microwave-electrostatic multi-field coupling technology is matched, PPS crystallization is promoted, the thermal stability of the material is improved, directional arrangement of the carbon fibers is induced, a three-dimensional heat conduction network is constructed, the thermal conductivity of the material is improved, and the excellent electrical insulation performance is kept.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyphenylene sulfide composite materials, in particular to a preparation method of polyphenylene sulfide composite materials. BACKGROUND

[0002] As a special engineering plastic, polyphenylene sulfide (PPS) is widely used in aerospace, electronics, automobile manufacturing and other fields due to its excellent high-temperature resistance, chemical stability and mechanical strength. However, with the increasing demand for comprehensive performance of materials in modern industry, the flame retardancy, thermal insulation and smoke suppression of traditional PPS materials in extreme environments have been difficult to meet the needs of high-end applications.

[0003] In terms of flame retardancy, traditional PPS materials mainly rely on the addition of halogen or phosphorus flame retardants, but such flame retardants have the problems of poor thermal stability, easy precipitation and secondary pollution; in terms of thermal insulation performance, PPS materials can improve thermal resistance by filling inorganic thermal insulation fillers, but uneven dispersion of fillers and weak interfacial bonding can easily lead to a decrease in mechanical properties of the materials; in terms of smoke suppression performance, PPS is prone to release a large amount of toxic smoke during combustion, and existing smoke suppression technologies such as adding magnesium hydroxide have the defects of large addition amount and poor compatibility.

[0004] Therefore, a preparation method of polyphenylene sulfide composite materials is proposed to improve the flame retardant efficiency and smoke suppression performance of PPS materials. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a preparation method of polyphenylene sulfide composite materials, which solves the problems raised in the background art.

[0006] To achieve the above purpose, the present application realizes the following technical scheme: a preparation method of polyphenylene sulfide composite materials, specifically comprising the following steps: S1, ultrasonically disperse bamboo-derived nanocellulose and flame-retardant reinforcing additives in deionized water for 25-30 minutes to obtain a suspension, add polyphenylene sulfide powder, and blend and granulate through a double-screw extruder at 290-310℃ to obtain a hybrid masterbatch; S2, mix the interfacial coupling agent with the hybrid masterbatch, then add it to a double-screw extruder, add a microwave heating environment with a frequency of 2.45 GHz and a power of 1.5 kW, and add a static electric field environment with a voltage of 10 kV / cm, melt blend at 300-320℃ to obtain a thermally conductive modified polyphenylene sulfide composite material; S3, melt extrude the polyphenylene sulfide to obtain a support bottom layer; S4, melt extrude the thermally conductive modified polyphenylene sulfide composite material onto the support bottom layer to obtain a thermal insulation core layer; S5, after the heat-conducting modified polyphenylene sulfide composite material is mixed with the aerogel microcapsule, the heat-conducting modified polyphenylene sulfide composite material is melt-extruded onto the heat insulation core layer to obtain a smoke suppression interlayer; S6, the hybrid master batch is melt-extruded onto the smoke suppression interlayer to obtain a response outer layer.

[0007] The application further provides that, in S1, the bamboo-derived nanocellulose, the flame-retardant reinforcing additive and the polyphenylene sulfide powder are in a mass ratio of 1-3:2-6:68.5-82.5.

[0008] The application further provides that, the preparation method of the flame-retardant reinforcing additive comprises: Ti3AlC2 powder is mixed with 40% hydrofluoric acid solution at a mass ratio of 1:25, stirred at 50 DEG C for 24 hours, the Al layer is etched, the etching product is washed with deionized water until pH is greater than or equal to 6, centrifuged at 3500 rpm for 5 minutes, and the Ti3C2Tx MXene sheet layer is collected; 0.2 mmol of ZrCl4 and 0.2 mmol of terephthalic acid are dissolved in 20 mL of DMF organic solvent, 1 mL of glacial acetic acid is added, and solvent thermal reaction is carried out at 120 DEG C for 24 hours to synthesize UiO-66 crystals; 50 mg of Ti3C2Tx MXene sheet layer and 50 mg of UiO-66 crystals are ultrasonically mixed in 10 mL of DMF organic solvent for 30 minutes, 10% of the total mass fraction of Ti3C2Tx MXene sheet layer and UiO-66 crystals is added to the phytic acid, and stirring is carried out at 60 DEG C for 4 hours to obtain the flame-retardant reinforcing additive.

[0009] The application further provides that, the preparation method of the interface coupling agent comprises: CsPbBr3 perovskite nanocrystals and thermoplastic polyurethane are mixed in tetrahydrofuran, long-chain silane coupling agent KH570 is added, and stirring is carried out at 60 DEG C for 4 hours, wherein the mass fractions of the CsPbBr3 perovskite nanocrystals, the thermoplastic polyurethane and the long-chain silane coupling agent KH570 are 1.5%, 2% and 0.5% respectively. The microspheres are prepared by a spray drying method, the inlet temperature is 120 DEG C, and the outlet temperature is 60 DEG C, and the microspheres are used as the interface coupling agent.

[0010] The application further provides that, the mass ratio of the interface coupling agent and the hybrid master batch is 4-6:94-96.

[0011] The application further provides that, the mass ratio of the heat-conducting modified polyphenylene sulfide composite material and the aerogel microcapsule is 1-3:97-99.

[0012] The application further provides that, the preparation method of the aerogel microcapsule comprises: The SiO2 aerogel and the thermoplastic polyurethane are mixed in dichloromethane, the mass fractions of the SiO2 aerogel and the thermoplastic polyurethane are 5% and 10% respectively, after ultrasonic dispersion for 30 min, stirring at 500 rpm at 30 DEG C until dichloromethane volatilizes, collecting the aerogel microcapsules by centrifugation, washing with deionized water for three times, and vacuum drying to obtain the aerogel microcapsules.

[0013] The application further provides that the thickness ratio of the support bottom layer, the heat insulation core layer, the smoke suppression interlayer and the response outer layer is 3-5:1-3:5-7:2-4.

[0014] The application provides a preparation method of a polyphenylene sulfide composite material. (1) The application constructs a four-dimensional protection system of a response outer layer-a smoke suppression interlayer-a heat insulation core layer-a support bottom layer, under fire conditions, the MXene layers in the response outer layer and the UiO-66 crystals synergistically form a dense carbon layer to block heat transfer, the CsPbBr3 quantum dots in the smoke suppression interlayer capture burning free radicals and adsorb smoke particles, the carbon fibers in the heat insulation core layer are arranged in a direction to form a high-efficiency heat resistance network, which effectively improves the limiting oxygen index of the material, reduces the smoke density grade, and cooperates with a microwave-electrostatic multi-field coupling technology to promote PPS crystallization, improve the thermal stability of the material, induce the directional arrangement of carbon fibers, construct a three-dimensional heat conduction network, improve the thermal conductivity of the material, and maintain excellent electrical insulation performance.

[0015] (2) The application prepares low-density aerogel microcapsules by compounding SiO2 aerogel and thermoplastic polyurethane, which are uniformly dispersed in a PPS matrix to form a closed-cell foaming structure, thereby reducing the density of the material, achieving weight reduction, maintaining thermal stability in a wide temperature range of-60 DEG C to 260 DEG C, and being suitable for lightweight protection requirements in extreme temperature environments. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0017] The embodiments of the application provide the following technical solutions: Embodiment 1 The application provides a preparation method of a polyphenylene sulfide composite material. The high-heat-insulation and smoke-suppression polyphenylene sulfide composite material comprises, from bottom to top, a support bottom layer, a heat insulation core layer, a smoke suppression interlayer and a response outer layer, and the method specifically comprises the following steps: S1, 200g of bamboo-derived nanocellulose and 500g of flame-retardant reinforcing additive were ultrasonically dispersed in deionized water for 28min to obtain a suspension, 7500g of polyphenylene sulfide powder was added, and the mixture was blended and granulated by a double screw extruder at 300℃ to obtain a hybrid master batch, wherein the preparation method of the bamboo-derived nanocellulose comprises: The bamboo was crushed to a particle size of ≤1 mm, washed with deionized water for 3 times, and dried at 60℃ for 24h; 200g of bamboo powder was mixed with 4000g of 10% sodium chlorite solution, stirred at 80℃ for 2h, and the lignin was removed; After filtration, 200g of 5% sodium hydroxide solution was used to treat at 90℃ for 1h to remove hemicellulose; 200g of chemically treated bamboo fibers were mixed with 10000g of deionized water, and the mixture was treated by a 100MPa high-pressure homogenizer for 5 times to obtain a BNC suspension; Centrifugation at 8000rpm for 10min, freeze-drying at-50℃ for 48h, and obtaining bamboo-derived nanocellulose.

[0018] The preparation method of the flame-retardant reinforcing additive comprises: 10g of Ti3AlC2 powder was mixed with 250g of 40% hydrofluoric acid solution, stirred at 50℃ for 24h to etch the Al layer, and the etching product was washed with deionized water until pH≥6, centrifuged at 3500rpm for 5min, and the Ti3C2Tx MXene sheet layer was collected; 0.2mmol of ZrCl4 and 0.2mmol of terephthalic acid were dissolved in 20mL of DMF organic solvent, 1mL of glacial acetic acid was added, and the mixture was solvothermal reacted at 120℃ for 24h to synthesize UiO-66 crystals; 50mg of Ti3C2Tx MXene sheet layer and 50mg of UiO-66 crystals were ultrasonically mixed in 10mL of DMF organic solvent for 30min, 10% of phytic acid based on the total mass of Ti3C2Tx MXene sheet layer and UiO-66 crystals was added, and the mixture was stirred at 60℃ for 4h to obtain the flame-retardant reinforcing additive.

[0019] S2, 50g of interface coupling agent was mixed with 950g of hybrid master batch, and then added into a double screw extruder, 2.45GHz, power 1.5kW microwave heating environment, and 10kV / cm electrostatic field environment were added, and the mixture was melt blended at 310℃ to obtain a heat-conducting modified polyphenylene sulfide composite material, wherein the preparation method of the interface coupling agent comprises: 1.5g of CsPbBr3 perovskite nanocrystals were mixed with 2g of thermoplastic polyurethane in 96g of tetrahydrofuran, 0.5g of long-chain silane coupling agent KH570 was added, and the mixture was stirred at 60℃ for 4h; The microspheres were prepared by a spray drying method, with an inlet temperature of 120°C and an outlet temperature of 60°C, and the interface coupling agent was used as the interface coupling agent.

[0020] S3, polyphenylene sulfide was melt extruded to obtain a support bottom layer, and the thickness of the support bottom layer was 40 pm.

[0021] S4, the heat-conducting modified polyphenylene sulfide composite material was melt extruded onto the support bottom layer to obtain a heat-insulating core layer, and the thickness of the heat-insulating core layer was 20 pm.

[0022] S5, 2g of the heat-conducting modified polyphenylene sulfide composite material was mixed with 98g of the aerogel microcapsules, and then melt extruded onto the heat-insulating core layer to obtain a smoke-suppressing interlayer, and the thickness of the smoke-suppressing interlayer was 60 pm. 5g of SiO2 aerogel and 10g of thermoplastic polyurethane were mixed in 85g of dichloromethane, and the mass fractions of the SiO2 aerogel and the thermoplastic polyurethane were 5% and 10% respectively, and after ultrasonic dispersion for 30 min, stirring was performed at 500 rpm at 30°C until the dichloromethane volatilized, the aerogel microcapsules were collected by centrifugation, and after being washed with deionized water for three times, vacuum drying was performed to obtain the aerogel microcapsules.

[0023] S6, the hybrid master batch was melt extruded onto the smoke-suppressing interlayer to obtain a response outer layer, and the thickness of the response outer layer was 30 pm.

[0024] Example 2 The difference between this example and Example 1 is that: S1, 100g of bamboo-derived nanocellulose and 600g of flame-retardant reinforcing additives were ultrasonically dispersed in deionized water for 25 min to obtain a suspension, 6850g of polyphenylene sulfide powder was added, and a double-screw extruder was used for blending and granulation at 290°C to obtain a hybrid master batch.

[0025] S2, 40g of the interface coupling agent was mixed with 960g of the hybrid master batch, and then added to a double-screw extruder, a microwave heating environment with a frequency of 2.45 GHz and a power of 1.5 kW, and a static electric field environment with a voltage of 10 kV / cm, and melt blending was performed at 300°C to obtain a heat-conducting modified polyphenylene sulfide composite material.

[0026] S3, polyphenylene sulfide was melt extruded to obtain a support bottom layer, and the thickness of the support bottom layer was 30 pm.

[0027] S4, the heat-conducting modified polyphenylene sulfide composite material was melt extruded onto the support bottom layer to obtain a heat-insulating core layer, and the thickness of the heat-insulating core layer was 30 pm.

[0028] S5, 1g of the heat-conducting modified polyphenylene sulfide composite material was mixed with 99g of the aerogel microcapsules, and then melt extruded onto the heat-insulating core layer to obtain a smoke-suppressing interlayer, and the thickness of the smoke-suppressing interlayer was 50 pm.

[0029] S6, melt-extruding the hybrid master batch onto the smoke suppression interlayer to obtain a responsive outer layer, the thickness of the responsive outer layer being 40 μm.

[0030] Example 3 The difference between this example and Example 1 is that: S1, after ultrasonic dispersion of 300 g of bamboo-derived nanocellulose and 200 g of flame-retardant reinforcing additives in deionized water for 30 min, a suspension is obtained, 8250 g of polyphenylene sulfide powder is added, and a hybrid master batch is obtained by blending and granulating through a twin-screw extruder at 310°C.

[0031] S2, after mixing 60 g of an interface coupling agent with 940 g of the hybrid master batch, the mixture is added to a twin-screw extruder, a microwave heating environment of 2.45 GHz and a power of 1.5 kW, and a static electric field environment of 10 kV / cm, and a thermally conductive modified polyphenylene sulfide composite material is obtained by melt blending at 320°C.

[0032] S3, melt-extruding the polyphenylene sulfide to obtain a support bottom layer, the thickness of the support bottom layer being 50 μm.

[0033] S4, melt-extruding the thermally conductive modified polyphenylene sulfide composite material onto the support bottom layer to obtain a heat-insulating core layer, the thickness of the heat-insulating core layer being 10 μm.

[0034] S5, after mixing 3 g of the thermally conductive modified polyphenylene sulfide composite material with 97 g of aerogel microcapsules, melt-extruding the mixture onto the heat-insulating core layer to obtain a smoke suppression interlayer, the thickness of the smoke suppression interlayer being 70 μm.

[0035] S6, melt-extruding the hybrid master batch onto the smoke suppression interlayer to obtain a responsive outer layer, the thickness of the responsive outer layer being 20 μm.

[0036] Simulation experiment The Fortron 0214G4 PPS material under the Tyconen flag is used as a comparative example, and the performance of the polyphenylene sulfide composite material prepared according to the scheme of the present application is tested and compared, and the indexes and corresponding test standards are shown in Table 1: Table 1 Performance Indicators Acquisition Mode Measurement Standard Tensile Strength (MPa) Universal Testing Machine Tensile Test ASTM D638, Tensile Rate 50 mm / min Flexural Strength (MPa) Three-Point Bending Test ASTM D790, Span 64 mm, Rate 2 mm / min Heat Deflection Temperature (°C) Thermomechanical Analysis (TMA) ASTM D648, Load 1.82 MPa Limiting Oxygen Index (%) Oxygen Index Burn Test ASTM D2863, Gas Flow Rate 40 mm / s Smoke Density Rating (SDR) Smoke Density Chamber Test ASTM E662, radiant intensity 25 kW / m 2 ]] Thermal Conductivity (W / (m·K)) Laser Thermal Conductivity Instrument Test ASTM E1461, Pulse Width 0.5 ms The test data results are shown in Table 2: Table 2 Performance Indicators Fortron 0214G4 The Invention Tensile Strength (MPa) 152 182 Flexural Strength (MPa) 220 256 Heat Deflection Temperature (°C) 260 275 Limiting Oxygen Index (%) 35.0 38.5 Smoke Density Rating (SDR) 65 42 Thermal Conductivity (W / (m·K)) 0.33 1.2 As can be seen from Table 2, in terms of mechanical properties, the tensile strength of the material is improved by 19.7% compared with Fortron 0214G4 through the synergistic reinforcing effect of MXene sheets and carbon fibers and the improvement of interlayer bonding force by the interface coupling agent KH570; the bending strength is improved by 16.4% through the three-dimensional thermal conduction network formed by the electric field oriented carbon fibers; In terms of thermal stability, the heat distortion temperature is increased by 5.8℃ compared with Fortron 0214G4, due to the regulation of PPS crystallinity by flame-retardant reinforcing aids and the heat shield effect of aerogel microcapsules; In terms of flame retardation, the limiting oxygen index is increased by 10.0%, and the smoke density rating is reduced by 35.4%, indicating the synergistic effect of the capture ability of CsPbBr3 quantum dots for combustion free radicals and the smoke suppression effect of SiO2 aerogel; In terms of thermal insulation, the thermal conductivity is increased by 263.6%, mainly due to the efficient heat conduction path formed by the directional arrangement of carbon fibers and the multi-level thermal insulation structure of aerogel microcapsules.

[0037] In summary, the four-dimensional gradient structure design of the supporting bottom layer, the thermal insulation core layer, the smoke suppression sandwich layer and the response outer layer realizes the synchronous improvement of mechanical properties, thermal stability, flame retardation and thermal insulation performance. Especially in terms of limiting oxygen index, smoke density rating and thermal conductivity, these key indicators show significant advantages over existing commercial PPS materials, which can meet the stringent requirements of high-end fields such as aerospace and new energy vehicle battery packs for material comprehensive performance.

[0038] Although embodiments of the present application have been shown and described, it will be understood by those having ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a polyphenylene sulfide composite material, characterized in that: The specific steps include: S1. Ultrasonic dispersion of bamboo-derived nanocellulose and a flame retardant reinforcing agent in deionized water for 25 to 30 minutes to obtain a suspension, adding polyphenylene sulfide powder, and blending and granulating the mixture at 290-310° C. using a twin-screw extruder to obtain a hybrid masterbatch. S2. After mixing the interfacial coupling agent and the hybrid masterbatch, the mixture was added to a twin-screw extruder, and a microwave heating environment of 2.45 GHz and 1.5 kW power and an electrostatic field environment of 10 kV / cm were added, and the mixture was melt-blended at 300-320°C to obtain a thermally conductive modified polyphenylene sulfide composite material; S3, melt-extrude polyphenylene sulfide to obtain a supporting bottom layer; S4, melt-extruding the thermally conductive modified polyphenylene sulfide composite material onto the supporting bottom layer to obtain a thermal insulation core layer; S5, mixing the thermally conductive modified polyphenylene sulfide composite material with the aerogel microcapsules, and then melt-extruding the mixture onto the thermal insulation core layer to obtain a smoke suppression interlayer; S6. Melt-extrude the hybrid masterbatch onto the smoke suppression interlayer to obtain a responsive outer layer.

2. The method for preparing the polyphenylene sulfide composite material according to claim 1, wherein: The mass ratio of the bamboo-derived nanocellulose, the flame retardant reinforcing agent and the polyphenylene sulfide powder in S1 is: 1-3: 2-6: 68.5-82.

5.

3. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The preparation method of the flame retardant reinforcing auxiliary agent comprises: Ti3AlC2 powder was mixed with 40% hydrofluoric acid solution at a mass ratio of 1:25 and stirred at 50°C for 24 hours to etch the Al layer. The etched product was washed with deionized water to a pH ≥ 6 and centrifuged at 3500 rpm for 5 minutes to collect the Ti3C2Tx MXene sheets. 0.2 mmol of ZrCl4 and 0.2 mmol of terephthalic acid were dissolved in 20 mL of DMF organic solvent, 1 mL of glacial acetic acid was added, and the reaction was carried out at 120 °C for 24 h to synthesize UiO-66 crystals; 50 mg of Ti3C2Tx MXene flakes and 50 mg of UiO-66 crystals were ultrasonically mixed in 10 mL of DMF organic solvent for 30 minutes. Phytic acid with a total mass fraction of 10% of the Ti3C2Tx MXene flakes and UiO-66 crystals was added, and the mixture was stirred at 60°C for 4 hours to obtain a flame retardant reinforcing agent.

4. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The preparation method of the interface coupling agent comprises: CsPbBr3 perovskite nanocrystals and thermoplastic polyurethane were mixed in tetrahydrofuran, and long-chain silane coupling agent KH570 was added. The mixture was stirred at 60°C for 4 hours. The mass fractions of CsPbBr3 perovskite nanocrystals, thermoplastic polyurethane and long-chain silane coupling agent KH570 were 1.5%, 2% and 0.5% respectively. The microspheres were prepared by spray drying with an inlet temperature of 120 °C and an outlet temperature of 60 °C as the interfacial coupling agent.

5. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The mass ratio of the interface coupling agent to the hybrid masterbatch is 4-6:94-96.

6. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The mass ratio of the thermally conductive modified polyphenylene sulfide composite material to the aerogel microcapsule is 1-3:97-99.

7. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The preparation method of the aerogel microcapsule comprises: SiO2 aerogel and thermoplastic polyurethane were mixed in dichloromethane, with the mass fractions of SiO2 aerogel and thermoplastic polyurethane being 5% and 10%, respectively. After ultrasonic dispersion for 30 minutes, the mixture was stirred at 500 rpm at 30°C until the dichloromethane evaporated. The aerogel microcapsules were collected by centrifugation, washed three times with deionized water, and then vacuum dried to obtain the aerogel microcapsules.

8. The method for preparing the polyphenylene sulfide composite material according to claim 1 or 2, characterized in that: The thickness ratio of the supporting bottom layer, the heat-insulating core layer, the smoke-suppressing interlayer and the response outer layer is: 3-5: 1-3: 5-7: 2-4.