Super-tough polyphenylene sulfide resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer material synthesis, and particularly discloses super-tough polyphenylene sulfide resin and a preparation method and application thereof.The method comprises the following steps that sodium sulfide and a sodium hydroxide solution are heated and mixed in the nitrogen atmosphere; raising the temperature again, performing decompression dehydration, and adding N-methyl pyrrolidone; adding p-dichlorobenzene and a catalyst for reaction; cooling, and carrying out solid-liquid separation on the polymer mixed slurry to obtain a solid material; and drying the solid material in vacuum. According to the super-tough polyphenylene sulfide resin as well as the preparation method and the application thereof, the super-tough polyphenylene sulfide resin with high molecular weight and low molecular weight distribution can be directly prepared at a synthesis end, and a low-temperature-freezing-resistant super-tough polyphenylene sulfide resin composite material can be obtained through the super-tough polyphenylene sulfide resin; and therefore, the application in multiple fields such as cooling systems of new energy automobiles and water peripheries of household appliances is realized.

Description

Technical Field

[0001] This invention belongs to the field of polymer material synthesis technology, specifically relating to an ultra-tough polyphenylene sulfide resin, its preparation method, and its application. Background Technology

[0002] Polyphenylene sulfide (PPS), a thermoplastic polymer, is composed of alternating benzene rings and sulfur atoms. Due to the presence of benzene rings, its molecular structure is firm, while the intercalation of thioether bonds gives it a certain degree of flexibility. This special structure determines its excellent comprehensive properties and has broad application potential in many fields.

[0003] However, existing polyphenylene sulfide (PPS) suffers from significant performance defects: low molecular weight and a wide molecular weight distribution result in poor impact resistance and brittleness, which greatly limits its application range. To mitigate these adverse effects, researchers in the current technology typically use a method of blending large amounts of toughening agents with PPS and melt extruding to prepare PPS composites with a certain degree of toughness. However, this method often sacrifices the material's rigidity, strength, heat resistance, and processing fluidity, making it difficult to balance toughness and other key properties.

[0004] Studies have shown that high molecular weight and low molecular weight distribution play an important role in improving the toughness, elongation, and impact strength of PPS. Therefore, controlling the molecular weight and molecular weight distribution range of PPS is key to improving its toughness. Currently, numerous patents report methods for synthesizing high molecular weight PPS: Chinese invention patent CN 103242528 A discloses a two-stage reaction of sodium sulfide, p-dichlorobenzene, and phosphate in a solvent to generate linear high molecular weight PPS; Chinese invention patent CN104744698 A describes a method for synthesizing linear high molecular weight PPS resin using sodium sulfide and p-dichlorobenzene as raw materials in a composite solvent and co-solvent system via solution polycondensation and secondary polymerization; Chinese invention patent CN 109776798 A uses sulfur-containing compounds and halogenated aromatic compounds as raw materials, and basic compounds and fatty acids as polycondensation aids, to carry out a polycondensation reaction. After purification, a primary PPS product is obtained, which is then reacted with a chain extender at high temperature to generate high molecular weight PPS resin.

[0005] Although there are various methods for synthesizing high molecular weight PPS in the existing technology, there are few reports on methods for directly polymerizing ultra-tough PPS from the synthesis end. Moreover, existing synthesis methods cannot simultaneously achieve high molecular weight, low molecular weight distribution and excellent low temperature freezing toughness of PPS, which cannot meet the needs of new energy vehicles, home appliances and other fields in extremely cold environments.

[0006] Therefore, there is a need in the field to develop an ultra-tough polyphenylene sulfide resin, its preparation method, and its applications, which can effectively solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide an ultra-tough polyphenylene sulfide resin, its preparation method, and its applications. This invention allows for the direct synthesis of ultra-tough polyphenylene sulfide resins with high molecular weight and low molecular weight distribution, overcoming the problems of brittleness, poor impact resistance, and the sacrifice of other properties during blending for toughening in existing PPS. Furthermore, this ultra-tough polyphenylene sulfide resin can be used to prepare low-temperature resistant ultra-tough polyphenylene sulfide resin composites, enabling their application in multiple fields such as cooling systems for new energy vehicles and water-related components of household appliances, meeting the requirements for use in extremely cold environments.

[0008] To achieve the above objectives, the present invention provides a method for preparing ultra-tough polyphenylene sulfide resin, comprising the following steps: Step S1: Weigh out the following components according to the molar ratio of sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and catalyst: (1.05-1.15):(0.1-0.5):(1.00-1.25):(2.00-3.50):(3.15-3.45); the catalyst is one or a combination of lithium chloride, lithium benzoate, lithium acetate, and lithium stearate. Sodium sulfide and sodium hydroxide solution were added to a 50L reactor and heated and mixed for the first time under a nitrogen atmosphere to ensure that the sodium sulfide and sodium hydroxide solution were fully mixed to obtain mixed solution A. Step S2: After heating the mixed solution A for the second time in the reactor, dehydrate it under reduced pressure. During the dehydration process, the dehydration rate is kept at 92-97 wt% to obtain PPS with high yield and best product quality. Add N-methylpyrrolidone and continue stirring to form a homogeneous thiophenol salt active system to obtain mixed solution B. Step S3: Add p-dichlorobenzene and catalyst to mixed solution B; replace the air in the reactor 3-5 times under the condition of nitrogen flow rate of 100-200 L / min, and then seal the reactor for polymerization reaction; Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 140-150℃, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. Then, after washing several times with deionized water, a solid material is obtained. After vacuum drying, a super-tough polyphenylene sulfide resin with a high molecular weight and low molecular weight distribution range is obtained.

[0009] Preferably, in step S1, the purity of sodium sulfide is 99.98 wt%, the purity of sodium hydroxide is 99.98 wt%, the purity of N-methylpyrrolidone solvent is 99.98 wt%, and the purity of dichlorobenzene is 99.98 wt%.

[0010] Preferably, in step S1, the first heating is specifically performed by heating to 120°C at a heating rate of 10°C / min and holding for 30min to allow the sodium sulfide and sodium hydroxide solution to mix thoroughly.

[0011] Preferably, in step S2, the second heating is specifically to heat to 200-220°C at a heating rate of 5°C / min; The stirring speed is 100-200 rpm, and the stirring time is 30-60 minutes.

[0012] Preferably, in step S3, the polymerization reaction specifically involves: raising the reactor temperature to 220-235°C at a rate of 2-4°C / min, reacting at this temperature for 1-2 hours to complete the initiation of the polymerization reaction and initial chain growth; slowly raising the temperature to 245-255°C at a rate of 1-2.5°C / min, and reacting at this constant temperature for 2-3 hours. This stage is the main growth period of the molecular chain, and gentle heating is beneficial for the uniform increase of molecular weight; finally, maintaining the temperature at 265-275°C and reacting for 1-2 hours. This stage aims to promote the complete reaction and further regularize the formed polymer chain segments, which helps to reduce the molecular weight distribution.

[0013] Preferably, in step S5, the vacuum drying temperature is 120-140℃ and the vacuum drying time is 8-12 hours.

[0014] The present invention also provides a method for preparing super-tough polyphenylene sulfide resin and the resulting super-tough polyphenylene sulfide resin.

[0015] This invention also provides an application of ultra-tough polyphenylene sulfide resin in the cooling system of new energy vehicles and the water peripheral of household appliances. The ultra-tough polyphenylene sulfide resin is blended with a toughening agent to prepare a low-temperature freezing resistant ultra-tough polyphenylene sulfide resin composite material.

[0016] Preferably, the blending of the ultra-tough polyphenylene sulfide resin and the toughening agent is specifically carried out by: extruding the ultra-tough polyphenylene sulfide resin and the toughening agent through a twin-screw extruder to obtain a low-temperature freezing resistant ultra-tough polyphenylene sulfide resin composite material.

[0017] Preferably, the toughening agent is a polyolefin-based elastomer, and its addition amount is 0-5 wt% of the weight of the ultra-tough polyphenylene sulfide resin. When polyolefin-based elastomers are used as toughening agents in the preparation of composite materials, they work synergistically with ultra-tough PPS resin to further improve the low-temperature toughness and impact resistance of the composite materials without sacrificing other material properties.

[0018] The extrusion temperatures of the blend extrusion are 270, 270, 295, 295, 295, 285, 285, 285, 280, 280, and 280℃ along the twin screw from the feed section to the discharge section, the die head temperature is 310℃, and the screw speed is 250 rpm.

[0019] The present invention utilizes the above-mentioned ultra-tough polyphenylene sulfide resin, its preparation method, and its application, with the following beneficial effects: (1) This invention utilizes a high-temperature polymerization reaction of sodium sulfide aqueous solution, sodium hydroxide aqueous solution, and p-dichlorobenzene in N-methylpyrrolidone solvent. By controlling the molar ratio of each component and the synthesis process, including adjusting the dehydration rate and selecting a catalyst, a super-tough PPS resin with high molecular weight and low molecular weight distribution is obtained. This super-tough PPS resin can be blended and extruded with a small amount of toughening agent to obtain a low-temperature freezing resistant super-tough polyphenylene sulfide resin composite material.

[0020] (2) The low-temperature freezing resistant ultra-tough PPS resin composite material prepared in this invention can be applied to multiple fields such as the cooling system of new energy vehicles and the water surrounding of household appliances. It can provide ample space for water to freeze and expand in extremely cold weather, and avoid the cracking of parts causing damage to key automotive systems and household appliances.

[0021] (3) The present invention is simple to operate, has a short production cycle, and can be manufactured on a large scale in the preparation of ultra-tough PPS resin. At the same time, the low-temperature freezing resistant ultra-tough PPS resin composite material can be prepared by a simple, conventional, and large-scale extrusion method, which makes it easy to realize industrial production.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a test graph showing the effect of dehydration rate on molecular weight and molecular weight distribution in Experiment 1 of the present invention, which describes an ultra-tough polyphenylene sulfide resin, its preparation method, and its application. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] In this embodiment of the invention, all raw materials are purified before use, and the pressure during the dehydration stage of the dehydration pretreatment is controlled at -0.08 to -0.10 MPa. The polymerization reaction is carried out under nitrogen positive pressure (0.2-0.5 MPa) protection throughout.

[0027] Example 1 A method for preparing an ultra-tough polyphenylene sulfide resin includes the following steps: Step S1: Weigh out the sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and lithium chloride in a molar ratio of 1.05:0.1:1.00:2.00:3.15; A 44% sodium sulfide solution and a 50% sodium hydroxide solution were added to a 50L reactor. The mixture was heated to 120℃ at a rate of 10℃ / min under a nitrogen atmosphere and held for 30min for the first heating and mixing to obtain mixed solution A. Step S2: Heat the mixed solution A in a reactor to 210°C at a heating rate of 5°C / min, then dehydrate it under reduced pressure and keep the dehydration rate at 93 wt%. Add N-methylpyrrolidone and continue stirring at 150 rpm for 60 min to obtain mixed solution B. Step S3: Add p-dichlorobenzene and lithium chloride to mixed solution B; replace the air in the reactor 4 times under nitrogen flow rate of 150 L / min, and then seal the reactor for polymerization reaction; The polymerization reaction is as follows: the reactor temperature is raised to 225°C at a rate of 3°C / min, and the reaction is carried out at this temperature for 1.5 hours; the temperature is then slowly raised to 250°C at a rate of 2°C / min, and the reaction is carried out at this constant temperature for 2.5 hours; finally, the temperature is maintained at 270°C, and the reaction is carried out for 1.5 hours.

[0028] Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 145°C, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. After washing several times with deionized water, a solid material is obtained. After vacuum drying, a tough polyphenylene sulfide resin with a high molecular weight and low molecular weight distribution range is obtained.

[0029] Example 2 A method for preparing an ultra-tough polyphenylene sulfide resin includes the following steps: Step S1: Weigh out the sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and lithium chloride in a molar ratio of 1.10:0.30:1.15:2.25:3.25. A 44% sodium sulfide solution and a 50% sodium hydroxide solution were added to a 50L reactor. The mixture was heated to 120℃ at a rate of 10℃ / min under a nitrogen atmosphere and held for 30min for the first heating and mixing to obtain mixed solution A. Step S2: After heating the mixed solution A to 210°C in the reactor at a heating rate of 5°C / min, dehydrate it under reduced pressure and keep the dehydration rate at 95wt%. Add N-methylpyrrolidone and continue stirring at 150rpm for 60min to obtain mixed solution B. Step S3: Add p-dichlorobenzene and lithium chloride to mixed solution B; replace the air in the reactor 4 times under nitrogen flow rate of 150 L / min, and then seal the reactor for polymerization reaction; The polymerization reaction is as follows: the reactor temperature is raised to 225°C at a rate of 3°C / min, and the reaction is carried out at this temperature for 1.5 hours; the temperature is then slowly raised to 250°C at a rate of 2°C / min, and the reaction is carried out at this constant temperature for 2.5 hours; finally, the temperature is maintained at 270°C, and the reaction is carried out for 1.5 hours.

[0030] Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 145°C, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. After washing several times with deionized water, a solid material is obtained. After vacuum drying, a super-tough polyphenylene sulfide resin with a high molecular weight and low molecular weight distribution range is obtained.

[0031] Example 3 A method for preparing an ultra-tough polyphenylene sulfide resin includes the following steps: Step S1: Weigh out the sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and lithium chloride according to a molar ratio of 1.15:0.5:1.25:3.50:3.45; A 44% sodium sulfide solution and a 50% sodium hydroxide solution were added to a 50L reactor. The mixture was heated to 120℃ at a rate of 10℃ / min under a nitrogen atmosphere and held for 30min for the first heating and mixing to obtain mixed solution A. Step S2: Heat the mixed solution A in a reactor to 210°C at a heating rate of 5°C / min, then dehydrate it under reduced pressure and keep the dehydration rate at 97 wt%. Add N-methylpyrrolidone and continue stirring at 150 rpm for 60 min to obtain mixed solution B. Step S3: Add p-dichlorobenzene and lithium chloride to mixed solution B; replace the air in the reactor 4 times under nitrogen flow rate of 150 L / min, and then seal the reactor for polymerization reaction; The polymerization reaction is as follows: the reactor temperature is raised to 225°C at a rate of 3°C / min, and the reaction is carried out at this temperature for 1.5 hours; the temperature is then slowly raised to 250°C at a rate of 2°C / min, and the reaction is carried out at this constant temperature for 2.5 hours; finally, the temperature is maintained at 270°C, and the reaction is carried out for 1.5 hours.

[0032] Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 145°C, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. After washing several times with deionized water, a solid material is obtained. After vacuum drying, a super-tough polyphenylene sulfide resin with a high molecular weight and low molecular weight distribution range is obtained.

[0033] Example 4 A method for preparing a polyphenylene sulfide resin includes the following steps: Step S1: Weigh out the following components according to the molar ratio of sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and lithium acetate: 1.10:0.30:1.15:2.25:3.25. A 44% sodium sulfide solution and a 50% sodium hydroxide solution were added to a 50L reactor. The mixture was heated to 120℃ at a rate of 10℃ / min under a nitrogen atmosphere and held for 30min for the first heating and mixing to obtain mixed solution A. Step S2: After heating the mixed solution A to 210°C in the reactor at a heating rate of 5°C / min, dehydrate it under reduced pressure and keep the dehydration rate at 95wt%. Add N-methylpyrrolidone and continue stirring at 150rpm for 60min to obtain mixed solution B. Step S3: Add p-dichlorobenzene and lithium acetate to mixed solution B; replace the air in the reactor 4 times under nitrogen flow rate of 150 L / min, and then seal the reactor for polymerization reaction; The polymerization reaction is as follows: the reactor temperature is raised to 225°C at a rate of 3°C / min, and the reaction is carried out at this temperature for 1.5 hours; the temperature is then slowly raised to 250°C at a rate of 2°C / min, and the reaction is carried out at this constant temperature for 2.5 hours; finally, the temperature is maintained at 270°C, and the reaction is carried out for 1.5 hours.

[0034] Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 145°C, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. After washing several times with deionized water, a solid material is obtained. After vacuum drying, the solid material is obtained as polyphenylene sulfide resin.

[0035] Comparative Example 1 A method for preparing a polyphenylene sulfide resin includes the following steps: Step S1: Weigh out the sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and lithium chloride in a molar ratio of 1.10:0.30:1.15:2.25:3.25. A 44% sodium sulfide solution and a 50% sodium hydroxide solution were added to a 50L reactor. The mixture was heated to 120℃ at a rate of 10℃ / min under a nitrogen atmosphere and held for 30min for the first heating and mixing to obtain mixed solution A. Step S2: Heat the mixed solution A in a reactor to 210°C at a heating rate of 5°C / min, then dehydrate it under reduced pressure and keep the dehydration rate at 85 wt%. Add N-methylpyrrolidone and continue stirring at 150 rpm for 60 min to obtain mixed solution B. Step S3: Add p-dichlorobenzene and lithium chloride to mixed solution B; replace the air in the reactor 4 times under nitrogen flow rate of 150 L / min, and then seal the reactor for polymerization reaction; The polymerization reaction is as follows: the reactor temperature is raised to 225°C at a rate of 3°C / min, and the reaction is carried out at this temperature for 1.5 hours; the temperature is then slowly raised to 250°C at a rate of 2°C / min, and the reaction is carried out at this constant temperature for 2.5 hours; finally, the temperature is maintained at 270°C, and the reaction is carried out for 1.5 hours.

[0036] Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 145°C, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. After washing several times with deionized water, a solid material is obtained. After vacuum drying, the solid material is obtained as polyphenylene sulfide resin.

[0037] Experimental Example 1 The polyphenylene sulfide resins prepared in Examples 1-4 and Comparative Example 1 were subjected to performance tests, and the results are shown in Table 1.

[0038] The above-mentioned polyphenylene sulfide resin granules were added to an injection molding machine and molded into standard samples for testing. The tensile elongation at break was tested according to ISO 527 standard; the weight-average molecular weight was tested according to GB / T 36214 standard.

[0039] Table 1 Performance Test Results

[0040] As can be seen from the data in Table 1, the super-tough PPS resins prepared by the methods provided in Examples 1-4, by controlling the molar ratio of each component and the dehydration rate and catalyst during the polymerization reaction, can yield super-tough PPS resins with a weight-average molecular weight of 49,000-60,000 and a molecular weight distribution of 2-3. Figure 1 As shown.

[0041] Experimental Example 2 The super-tough polyphenylene sulfide resin prepared in Example 2 and conventional PPS resin (polyphenylene sulfide) were respectively blended and extruded with 2 wt% of the corresponding resin weight of polyolefin-based elastomer through a twin-screw extruder to obtain PPS composite materials.

[0042] The extrusion temperatures of the blending extrusion are 270, 270, 295, 295, 295, 285, 285, 285, 280, 280, and 280℃ respectively from the feed section to the discharge section of the twin screw. The die head temperature is 310℃ and the screw speed is 250 rpm.

[0043] The above-mentioned PPS composite material granules were added to an injection molding machine and molded into standard samples for testing. Low-temperature test conditions: -40℃, 24h; tensile elongation at break was tested according to ISO 527 standard; weight-average molecular weight was tested according to GB / T 36214 standard. The performance test results are shown in Table 2.

[0044] Table 2 Performance Test Results

[0045] As shown in Table 2, the ultra-tough polyphenylene sulfide resin composite material prepared by the embodiment of the present invention exhibits excellent toughness and low-temperature freezing resistance. Therefore, the ultra-tough polyphenylene sulfide resin composite material can be applied to multiple fields such as cooling systems of new energy vehicles and water-related components of household appliances. It can provide ample space for water to freeze and expand in extremely cold weather, avoiding cracking of parts and damage to key automotive systems and household appliances.

[0046] Therefore, this invention utilizes the aforementioned ultra-tough polyphenylene sulfide resin, its preparation method, and its applications to directly prepare ultra-tough polyphenylene sulfide resins with high molecular weight and low molecular weight distribution at the synthesis stage, overcoming the problems of existing PPS such as brittleness, poor impact resistance, and the sacrifice of other properties during blending for toughening. Furthermore, this ultra-tough polyphenylene sulfide resin can be used to prepare low-temperature resistant ultra-tough polyphenylene sulfide resin composites, thereby enabling the application of these composites in multiple fields such as cooling systems for new energy vehicles and water-related components of household appliances, meeting the requirements for use in extremely cold environments.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an ultra-tough polyphenylene sulfide resin, characterized in that, Includes the following steps: Step S1: Weigh out the following components according to the molar ratio of sodium sulfide, sodium hydroxide, p-dichlorobenzene, N-methylpyrrolidone, and catalyst: (1.05-1.15):(0.1-0.5):(1.00-1.25):(2.00-3.50):(3.15-3.45); the catalyst is one or a combination of lithium chloride, lithium benzoate, lithium acetate, and lithium stearate. Sodium sulfide and sodium hydroxide solutions were added to a 50L reactor and mixed under a nitrogen atmosphere to obtain mixed solution A. Step S2: After heating the mixed solution A for the second time in the reactor, dehydrate it under reduced pressure, keeping the dehydration rate at 92-97 wt% during the process; add N-methylpyrrolidone and continue stirring to obtain mixed solution B; Step S3: Add p-dichlorobenzene and catalyst to mixed solution B; After replacing the air in the reactor 3-5 times with nitrogen at a flow rate of 100-200 L / min, the reactor is sealed for polymerization. Step S4: After the reaction is complete, the temperature is lowered to 180°C at a rate of 15°C / min and held for 30 minutes to obtain the polymer slurry. Step S5: When the temperature of the polymer slurry drops to 140-150℃, the polymer slurry is placed in a centrifugal filter for solid-liquid separation. Then, after washing several times with deionized water, a solid material is obtained. After vacuum drying, the super-tough polyphenylene sulfide resin is obtained.

2. The method for preparing a super-tough polyphenylene sulfide resin according to claim 1, characterized in that: In step S1, the purity of sodium sulfide is 99.98 wt%, the purity of sodium hydroxide is 99.98 wt%, the purity of N-methylpyrrolidone solvent is 99.98 wt%, and the purity of dichlorobenzene is 99.98 wt%.

3. The method for preparing a super-tough polyphenylene sulfide resin according to claim 1, characterized in that: In step S1, the first heating is specifically performed by heating to 120°C at a heating rate of 10°C / min and holding for 30min.

4. The method for preparing a super-tough polyphenylene sulfide resin according to claim 1, characterized in that: In step S2, the second heating is specifically to heat to 200-220℃ at a heating rate of 5℃ / min; The stirring speed is 100-200 rpm, and the stirring time is 30-60 minutes.

5. The method for preparing an ultra-tough polyphenylene sulfide resin according to claim 1, characterized in that, In step S3, the polymerization reaction is specifically carried out as follows: the reactor temperature is raised to 220-235℃ at a rate of 2-4℃ / min, and the reaction is carried out at this temperature for 1-2 hours; the temperature is raised to 245-255℃ at a rate of 1-2.5℃ / min, and the reaction is carried out at a constant temperature for 2-3 hours; finally, the temperature is maintained at 265-275℃, and the reaction is carried out for 1-2 hours.

6. The method for preparing a super-tough polyphenylene sulfide resin according to claim 1, characterized in that, In step S5, the vacuum drying temperature is 120-140℃, and the vacuum drying time is 8-12 hours.

7. A super-tough polyphenylene sulfide resin prepared by the method of any one of claims 1-6.

8. The application of the ultra-tough polyphenylene sulfide resin as described in claim 7 in the cooling system of new energy vehicles and the water peripheral of household appliances, characterized in that: Ultra-tough polyphenylene sulfide resin was blended with a toughening agent to prepare a low-temperature freezing resistant ultra-tough polyphenylene sulfide resin composite material.

9. The application according to claim 8, characterized in that, The specific process of blending super-tough polyphenylene sulfide resin with toughening agent is as follows: super-tough polyphenylene sulfide resin and toughening agent are blended and extruded through a twin-screw extruder to obtain a low-temperature freezing resistant super-tough polyphenylene sulfide resin composite material.

10. The application according to claim 9, characterized in that: The toughening agent is a polyolefin-based elastomer, and its addition amount is 0-5 wt% of the weight of the ultra-tough polyphenylene sulfide resin. The extrusion temperatures of the blend extrusion are 270, 270, 295, 295, 295, 285, 285, 285, 280, 280, and 280℃ along the twin screw from the feed section to the discharge section, the die head temperature is 310℃, and the screw speed is 250 rpm.

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