A sulfone polymer and a purification method thereof

Abstract

The invention discloses a sulfone polymer and a purification method thereof, belonging to the technical field of polymer material preparation. In the purification method of the sulfone polymer provided by the invention, a reaction solvent and a reaction solvent containing a porogen of a specific type and content are sequentially added at the end of a polymerization reaction, so that a loose porous structure can be formed on the surface of a precipitate in the subsequent precipitation process, and the residual solvent, reaction monomers and the like in the sulfone polymer are extracted in conjunction with subsequent crushing and washing, thereby obtaining a sulfone polymer with high purity, high yield and excellent performance. In addition, due to the formation of the loose porous structure, the purification method provided by the invention can greatly reduce the demand for washing water used in subsequent washing, thereby achieving the effect of energy saving and emission reduction.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a sulfone polymer and a purification method thereof. Background Art

[0002] Sulfone polymers are a class of high-performance amorphous thermoplastic engineering plastics containing characteristic diaryl sulfone chain segments. They are widely used because of their excellent properties such as high mechanical strength, heat resistance, oxidation resistance, hydrolysis resistance, acid and alkali resistance. Sulfone polymers are slightly amber non-crystalline transparent or translucent polymers and are amorphous, thermoplastic resins. Researchers in this field have found that after the polymerization solution is precipitated in the precipitation bath, the surface of the material is relatively dense, making it difficult to extract impurities from the resin. The purification stage requires the use of a large amount of poor solvents or water to purify the resin, but the effect is limited.

[0003] Different methods for purifying sulfone polymers have been proposed in the prior art. For example, in the prior art CN114561013, an emulsifier-deionized water compound solution is added dropwise to a polysulfone resin solution to form a gel-like solid, which is then crushed and purified to remove impurities. However, in actual operation, it is difficult to control the resin to form a gel, and only part of the resin can form a gel, while most of it becomes a solid, resulting in a low yield of high-quality resin products. For example, CN200510020111.X discloses a polyethersulfone purification method, which uses polyethylene glycol and purifies the product by boiling it multiple times under a high pressure of 1MPa. However, the high-pressure boiling time used in this purification method is too long, which will cause the molecular chain segments to break, thereby reducing the product performance, and the high temperature and high pressure conditions have a high safety risk, which is not a good purification method in industrial production. For example, CN112552528A discloses a method for removing solvents from a high-temperature resistant polymer solution, in which a desorbent is added to an extraction tank and supercritical carbon dioxide is introduced to remove the residual solvent in the resin; however, the manufacturing process of the desorbent in this method is complicated, the pressure and temperature of supercritical carbon dioxide are very high, and it can only remove the solvent, but has limited effect on removing the reaction monomer.

[0004] Therefore, it is urgent to provide a simple, safe, high-yield purification method for sulfone polymers with excellent properties. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a sulfone polymer and a purification method thereof which are simple and safe to operate, energy-saving and environmentally friendly, have a high yield, and have excellent performance.

[0006] To achieve the above object, in a first aspect of the present invention, the present invention provides a sulfone polymer, in which the residual reaction monomer is below 9.86 ppm and the residual reaction solvent is below 192 ppm.

[0007] The reaction monomer and the reaction solvent vary with the specific reaction materials of the sulfone polymer. For example, if the reaction solvent used in the preparation of the sulfone polymer is cyclopentane sulfone, the reaction solvent residue is the cyclopentane sulfone residue; if the reaction monomer used in the preparation of the sulfone polymer is 4,4'-biphenol, the reaction monomer residue is the 4,4'-biphenol residue.

[0008] In a second aspect of the present invention, the present invention provides a method for purifying a sulfone polymer, the purification method comprising the following steps:

[0009] The raw materials for synthesizing sulfone polymer are mixed and subjected to polymerization reaction until the reaction solution reaches the target viscosity, a polymerization reaction solvent is added to the reaction solution, and then a mixed solution of a porogen and the polymerization reaction solvent is added at a rate of 50-500 g / min and stirred, and then added to water for precipitation, and the precipitate is collected and crushed, washed, and dried to obtain a sulfone polymer;

[0010] Wherein, the mass percentage of the porogen is 0.1-2% based on the total mass of the raw materials for synthesizing the sulfone polymer;

[0011] The porogen is selected from at least one of polyvinyl pyrrolidone, polyethylene glycol or an inorganic salt.

[0012] In the purification method of sulfone polymer provided by the present invention, a reaction solvent and a reaction solvent containing a porogen of a specific type and content are sequentially added at the end of the polymerization reaction, so that a loose porous structure can be formed on the surface of the precipitate during the subsequent precipitation process, and the residual solvent, by-product salt and the like in the sulfone polymer are extracted in conjunction with subsequent crushing and washing, thereby obtaining a sulfone polymer with high purity, high yield and excellent performance; and the purification method provided by the present invention forms a loose porous structure, so that the demand for washing water used in subsequent washing is greatly reduced, thereby achieving the effect of energy saving and emission reduction.

[0013] The purification method provided by the present invention is suitable for the preparation and purification process of all sulfone polymers, for example, the sulfone polymer may be bisphenol A type polysulfone, polyether sulfone, polyphenyl sulfone and the like.

[0014] According to the performance of the target sulfone polymer, the viscosity of the polymerization reaction is detected. When the viscosity reaches the viscosity of the target sulfone polymer of 100-3000 cps, the subsequent purification step of the present invention is carried out. For example, when the prepared sulfone polymer is bisphenol A type polysulfone, the target viscosity of the reaction is 150-700 cps, when the prepared sulfone polymer is polyether sulfone, the target viscosity of the reaction is 200-900 cps, and when the prepared sulfone polymer is polyphenyl sulfone, the target viscosity of the reaction is 300-1200 cps.

[0015] According to different target sulfone polymers, the polymerization reaction solvent can be at least one of dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and diphenyl sulfone.

[0016] Preferably, when the sulfone polymer prepared is bisphenol A type polysulfone, the polymerization reaction solvent is N,N-dimethylacetamide or dimethyl sulfoxide, when the sulfone polymer prepared is polyethersulfone, the polymerization reaction solvent is cyclopentane sulfone, N,N-dimethylformamide or diphenyl sulfone, and when the sulfone polymer prepared is polyphenylsulfone, the polymerization reaction solvent is cyclopentane sulfone or N,N-dimethylformamide.

[0017] As a preferred embodiment of the purification method of the present invention, at least one of the following (a)-(c) is selected:

[0018] (a) the K value of the polyvinyl pyrrolidone is 10-110;

[0019] (b) the degree of polymerization of the polyethylene glycol is 300-9000;

[0020] (c) The inorganic salt is a chloride of Zr, Na, K or Mg.

[0021] The K value of the polyvinyl pyrrolidone is obtained by testing according to the chromatography method; the degree of polymerization of the polyethylene glycol is obtained by testing according to the method for pharmaceutical excipients in the 2015 edition (Volume 4) of the Pharmacopoeia of the People's Republic of China.

[0022] Preferably, the K value of the polyvinyl pyrrolidone is 15-90; and the degree of polymerization of the polyethylene glycol is 400-8000.

[0023] More preferably, the K value of the polyvinyl pyrrolidone is 30-90; and the degree of polymerization of the polyethylene glycol is 2000-6000.

[0024] The inventors have found that the K value of polyvinyl pyrrolidone and the degree of polymerization of polyethylene glycol represent the molecular weight levels of the two to a certain extent. When the molecular weight of the porogen increases within a certain range, the more micropores are formed on the surface of the sulfone polymer, and the residual reaction monomer and residual solvent after purification will be lower. However, when the molecular weights of polyvinyl pyrrolidone and polyethylene glycol are further increased, the residual reaction monomer and residual solvent of the obtained sulfone polymer increase, and the yield also shows a downward trend; and for inorganic salt porogens, the selection of different types of cations will also affect the comprehensive performance of the product; when the K value of the porogen polyvinyl pyrrolidone is further selected to be 30-90, the degree of polymerization of polyethylene glycol is 2000-6000, and the inorganic salt is of the above type, the obtained sulfone polymer not only has a higher yield, but also has better performance.

[0025] Exemplarily, the K value of the polyvinyl pyrrolidone can be any point value between 30 and 90 or a range value consisting of any two points, such as 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, etc. Due to space limitations, they are not listed here one by one. Within the preferred range of 30-90 of the present invention, better effects can be achieved.

[0026] Exemplarily, the degree of polymerization of the polyethylene glycol can be any point value between 2000-6000 or a range value consisting of any two points, such as 2000, 3000, 4000, 5000, 6000, etc. Due to space limitations, they are not listed here one by one. Within the preferred range of 2000-6000 of the present invention, better effects can be achieved.

[0027] As a preferred embodiment of the purification method of the present invention, the porogen is a mixture of an inorganic salt and polyvinyl pyrrolidone, a mixture of an inorganic salt and polyethylene glycol, or a mixture of polyvinyl pyrrolidone and polyethylene glycol.

[0028] As a preferred embodiment of the purification method of the present invention, the mass percentage of the inorganic salt is 10-40% based on the porogen.

[0029] The inventors have found that when the porogen is a mixture of an inorganic salt and polyvinyl pyrrolidone, a mixture of an inorganic salt and polyethylene glycol, or a mixture of polyvinyl pyrrolidone and polyethylene glycol, the comprehensive performance obtained is better than using a single porogen, especially when the mass percentage of the inorganic salt in the porogen mixture is further selected to be 10-40%, the comprehensive performance obtained is even better.

[0030] As a preferred embodiment of the purification method of the present invention, a mixed solution of the porogen and the polymerization reaction solvent is added at a rate of 100-300 g / min.

[0031] The inventors have found that the drop rate of the mixed solution has a significant effect on the purification effect of the sulfone polymer. The drop rate not only affects the purification efficiency, but also affects the performance of the product. Within a certain range, the increase in the drop rate can improve the efficiency and avoid the phenomenon of product color deepening due to the long drop time. However, with the further increase in the drop rate, the dispersion effect of the porogen will deteriorate, thereby reducing the purity of the product, and the residual reaction monomer and the residual reaction solvent will increase. When the drop rate is selected to be 50-500g / min, especially 100-300g / min, the overall effect is more excellent.

[0032] As a preferred embodiment of the purification method of the present invention, the mass percentage of the porogen is 0.5-1% based on the total mass of the raw materials for synthesizing the sulfone polymer.

[0033] The inventors have found that the amount of porogen added will also significantly affect the comprehensive performance of the product. If the amount of porogen added is too little, the surface will be loose and porous, resulting in a smaller structure, which will in turn lead to an increase in reaction monomers and solvent residues. If too much porogen is added, there will also be a trend of increasing reaction monomers and solvent residues, and the amount of water used in the subsequent process will also increase, and the purpose of energy conservation and emission reduction cannot be effectively achieved. When the amount of porogen added is selected to be 0.1-2%, especially 0.5-1%, the comprehensive performance obtained is excellent.

[0034] As a preferred embodiment of the purification method of the present invention, the stirring temperature is 140-180° C., the stirring speed is 200-700 r / min, and the stirring time is 20-40 min.

[0035] As a preferred embodiment of the purification method of the present invention, in the mixed solution of the porogen and the polymerization reaction solvent, the mass percentage of the porogen is 5-50%.

[0036] The inventors have found that when the mass percentage of the porogen in the mixed solution is 5-50%, it can better promote the formation of a loose porous structure on the surface of the sulfone polymer.

[0037] As a preferred embodiment of the purification method of the present invention, when the polymerization reaction solvent is added to the reaction solution, the mass of the added polymerization reaction solvent is 20-60% of the total mass of the raw materials for synthesizing the sulfone polymer.

[0038] When the polymerization reaction is carried out until the reaction liquid reaches the target viscosity, adding the above-mentioned mass percentage of the polymerization reaction solvent to the reaction liquid can reduce the solution viscosity and material temperature to appropriate values, thereby promoting the subsequent porogen effect.

[0039] As a preferred embodiment of the purification method of the present invention, the precipitation is to add the stirred material into flowing water at a rate of 1-5 kg / h to form material strip precipitation.

[0040] As a preferred embodiment of the purification method of the present invention, the washing is performed using water at a temperature of 80-100° C., and the number of washing times is 2-4 times.

[0041] As a preferred embodiment of the purification method of the present invention, the particle size after crushing is 0.05-0.8 mm.

[0042] As a preferred embodiment of the purification method of the present invention, the drying is vacuum drying, and the drying is performed until the water content is less than 0.5%.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] In the purification method of sulfone polymer provided by the present invention, by sequentially adding reaction solvent and reaction solvent containing porogen of specific type and content at the end of polymerization reaction, a loose porous structure can be formed on the surface of precipitate in the subsequent precipitation process, and the residual solvent, reaction monomer and the like in the sulfone polymer can be extracted with subsequent crushing and washing, thereby obtaining a sulfone polymer with high purity, high yield and excellent performance; and the purification method provided by the present invention forms a loose porous structure, and the demand for washing water used in subsequent washing is greatly reduced, thereby achieving the effect of energy saving and emission reduction. Specifically, the reaction monomer residue of the sulfone polymer prepared by the purification method of the present invention is less than 9.86ppm, the reaction solvent residue is 192ppm, the yield is more than 94.5%, and the b value of the reaction color is between 9.16-10.97; in the purification process, the amount of water used is less than 20.3 tons of water / ton of sulfone polymer, and the number of purification times is less than 2 times. DETAILED DESCRIPTION

[0045] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0046] Unless otherwise specified, the reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are commercially available and are from the same batch of raw materials.

[0047] Among them, polyvinyl pyrrolidone with a K value of 30 is expressed as PVP-30, and other polyvinyl pyrrolidones with different K values ​​are expressed similarly; polyethylene glycol with a polymerization degree of 2000 is expressed as PEG-2000, and other polyethylene glycols with different polymerization degrees are expressed similarly.

[0048] The polymerization reaction of Examples 1-18 of the present invention and Comparative Examples 1-8 is consistent until the reaction solution reaches the target viscosity. Specifically, 4.561 kg of cyclopentane sulfone, 0.853 kg of 4,4'-dichlorodiphenyl sulfone and 0.565 kg of 4,4'-biphenyl diphenol, 0.380 kg of sodium carbonate and 0.356 kg of xylene are quantitatively added to a 15L reactor, the reactor is evacuated, nitrogen is introduced for replacement three times, and the temperature is raised under nitrogen protection. The heating process is carried out according to the set program, and the reaction system is heated to 230-240 ° C and maintained for 2-3 hours until the target viscosity of 660 cps is reached. At this time, the reaction solution described in Examples 1-18 and Comparative Examples 1-8 is obtained.

[0049] The polymerization reaction of Example 19 of the present invention is carried out until the reaction liquid reaches the target viscosity, specifically: 3.852kg of cyclopentane sulfone, 0.879kg of 4,4'-dichlorodiphenyl sulfone and 0.753kg of 4,4'-dihydroxydiphenyl sulfone, 0.332kg of sodium carbonate and 0.365kg of xylene are quantitatively added to a 15L reactor, the reactor is evacuated, nitrogen is introduced for replacement three times, and the temperature is raised under nitrogen protection. The heating process is carried out according to the set program, and the reaction system is heated to 230-240°C and maintained for 2-3h until the target viscosity of 468cps is reached, which is the reaction liquid described in Example 19.

[0050] The polymerization reaction of Example 20 of the present invention is carried out until the reaction liquid reaches the target viscosity, specifically: 3.75kg of dimethyl sulfoxide, 0.758kg of 4,4'-dichlorodiphenyl sulfone and 0.545kg of bisphenol A, 0.332kg of sodium carbonate and 0.35kg of xylene are quantitatively added into a 15L reactor, the reactor is evacuated, nitrogen is introduced for replacement three times, and the temperature is increased under nitrogen protection. The heating process is carried out according to the set program, and the reaction system is heated to 230-240°C and maintained for 2-3h until the target viscosity of 354cps is reached. At this time, it is the reaction liquid described in Example 20.

[0051] Example 1

[0052] An embodiment of the present invention provides a sulfone polymer, wherein the purification method of the sulfone polymer comprises the following steps:

[0053] Add 50% of the total mass of the raw materials for synthesizing sulfone polymer into the reaction solution, maintain the material at 155°C, add 10% of the mass percentage of polyethylene glycol-2000 / sulfone mixed solution into the reaction kettle at a rate of 100g / min, wherein the amount of polyethylene glycol-2000 added is 1% of the total mass of the raw materials for synthesizing sulfone polymer; after the addition is completed, stir at 400r / min for 30min; after the stirring is completed, put the solution into flowing deionized water with a flow rate of 20kg / h at a flow rate of 1.82kg / h, the sulfone polymer forms material strips precipitate in the deionized water, separate the material strips precipitate, crush it into powder with a particle size of 0.05-0.8mm by a mechanical crusher, transfer the powder into a purification kettle, add deionized water 10 times the mass of the powder, stir and wash at 90°C for 30min, centrifuge and repeat washing twice, and place the washed powder in a vacuum drying oven to dry it to a water content of less than 0.5% to obtain polyphenylsulfone resin.

[0054] Example 2-16

[0055] The only difference between Examples 2-16 of the present invention and Example 1 is the type and amount of the porogen used, wherein the value (percentage) of the amount of the porogen added is based on the total mass of the raw materials for synthesizing the sulfone polymer. The specific differences are shown in Table 1;

[0056] Table 1

[0057]

[0058] Embodiment 17

[0059] The embodiment of the present invention provides a sulfone polymer. The only difference between the purification method of the sulfone polymer and that of Example 1 is that a 10% by mass polyethylene glycol-2000 / sulfolane mixed solution is added to the reactor at a rate of 50 g / min.

[0060] Embodiment 18

[0061] The embodiment of the present invention provides a sulfone polymer. The only difference between the purification method of the sulfone polymer and that of Example 1 is that a 10% by mass polyethylene glycol-2000 / sulfolane mixed solution is added to the reactor at a rate of 500 g / min.

[0062] Embodiment 19

[0063] The embodiment of the present invention provides a sulfone polymer. The only difference between the purification method of the sulfone polymer and that of Example 1 is that the reaction solution is different and the polymer is washed three times to finally obtain a polyethersulfone resin.

[0064] Embodiment 20

[0065] An embodiment of the present invention provides a sulfone polymer, wherein the purification method of the sulfone polymer comprises the following steps:

[0066] Add 20% of the total mass of raw materials for synthesizing sulfone polymer into the reaction solution, maintain the material at 175°C, add 45% of polyethylene glycol-6000 / cyclopentane sulfone mixed solution into the reaction kettle at a rate of 300g / min, wherein the amount of polyethylene glycol-6000 added is 0.5% of the total mass of the raw materials for synthesizing sulfone polymer; after the addition, stir at 700r / min for 30min; after the stirring, put the solution into flowing deionized water with a flow rate of 20kg / h at a flow rate of 1.82kg / h, the sulfone polymer forms material strips precipitate in the deionized water, separate the material strips precipitate, crush it into powder with a particle size of 0.05-0.8mm by a mechanical crusher, transfer the powder into a purification kettle, add deionized water 10 times the mass of the powder, stir and wash at 90°C for 30min, centrifuge and repeat washing twice, place the washed powder in a vacuum drying oven and dry it to a water content of less than 0.5%, and obtain bisphenol A type sulfone polymer resin.

[0067] Comparative Example 1

[0068] The comparative example of the present invention provides a sulfone polymer. The purification method of the sulfone polymer is as follows: a reaction liquid is put into flowing deionized water with a flow rate of 20 kg / h at a flow rate of 1.82 kg / h, the sulfone polymer forms a material strip precipitate in the deionized water, the material strip precipitate is separated, and a mechanical crusher is used to crush the powder with a particle size of 0.05-0.8 mm, the powder is transferred to a purification kettle, deionized water with a mass of 10 times of the powder is added, and the powder is stirred and washed at 90° C. for 30 minutes, centrifuged, and washed twice, and the washed powder is placed in a vacuum drying oven and dried to a water content of less than 0.5% to obtain a polyphenylsulfone resin.

[0069] Comparative Example 2

[0070] The comparative example of the present invention provides a sulfone polymer, and the only difference between the purification method of the sulfone polymer and that of the comparative example 1 is that the washing is repeated 6 times.

[0071] Comparative Example 3

[0072] The comparative example of the present invention provides a sulfone polymer. The only difference between the purification method of the sulfone polymer and that of Example 1 is that a 10% by mass polyethylene glycol-2000 / sulfolane mixed solution is added to the reactor at a rate of 10 g / min.

[0073] Comparative Example 4

[0074] The comparative example of the present invention provides a sulfone polymer, and the only difference between the purification method of the sulfone polymer and that of Example 1 is that a 10% by mass polyethylene glycol-2000 / sulfolane mixed solution is added to the reactor at a rate of 600 g / min.

[0075] Comparative Example 5

[0076] The comparative example of the present invention provides a sulfone polymer, and the only difference between the purification method of the sulfone polymer and that of Example 1 is that the amount of the porogen added is 4% based on the total mass of the raw materials for synthesizing the sulfone polymer.

[0077] Comparative Example 6

[0078] The comparative example of the present invention provides a sulfone polymer. The only difference between the purification method of the sulfone polymer and that of Example 1 is that the amount of the porogen added is 0.02% based on the total mass of the raw materials for synthesizing the sulfone polymer.

[0079] Comparative Example 7

[0080] The comparative example of the present invention provides a sulfone polymer, and the only difference between the purification method of the sulfone polymer and that of Example 1 is that the porogen is glucose.

[0081] Comparative Example 8

[0082] The comparative example of the present invention provides a sulfone polymer, and the only difference between the purification method of the sulfone polymer and that of Example 1 is that a 10% by mass polyethylene glycol-2000 / cyclopentane sulfone mixed solution is added to the reaction solution at a rate of 100 g / min, that is, no polymerization reaction solvent is added before this.

[0083] Effect Example 1

[0084] The effect examples of the present invention verify the performance of the sulfone polymers prepared in Examples 1-20 and Comparative Examples 1-8, and the test performance includes the following aspects:

[0085] 1) b value test: The powdered resin obtained by polymerization was extruded through a twin-screw extruder to obtain resin pellets, and injection molded at 360° C. to obtain a standard color plate with a thickness of 2 mm. The b value of the color plate was measured using a colorimeter according to ASTM D1925-1988;

[0086] 2) Reaction solvent residue: Deuterated chloroform was used to prepare a solution, and the sulfolane content in the resin was calculated based on the peak area ratio at δ=7.58 and δ=3.05 in the spectrum;

[0087] 3) Residual monomers in the reaction: the resin was dissolved in acetonitrile, extracted in ultrasound, filtered with a microporous filter membrane, and the residual monomers in the solution were tested by LC-MS.

[0088] 4) Yield: The yield is calculated as yield = mass of actual product / mass of theoretical product * 100%;

[0089] The results obtained are shown in Table 2;

[0090] Table 2

[0091]

[0092]

[0093] As can be seen from Table 2, when the technical solution of the present invention is adopted, the comprehensive performance of the obtained product is excellent, the residual monomer is below 9.86 ppm, the residual sulfolane is below 192 ppm, the yield is above 94.5%, and the b value of the reaction color is between 9.16-10.97;

[0094] It can be seen from Examples 1-4 that when the degree of polymerization of PEG is further selected to be 2000-6000, the comprehensive performance of the obtained product is more excellent; it can be seen from Examples 5-8 that when the K value of PVP is further selected to be 30-90, the comprehensive performance of the obtained product is more excellent, specifically, the reaction monomer residue of the obtained product is below 9.22ppm, the sulfolane residue is below 187ppm, the yield is above 98.1%, and the b value of the reaction color is between 9.75-10.85; it can be seen from Examples 1, 5, 9 and 11-14 that when the porogen is further selected to be a mixture of PEG and an inorganic salt or a mixture of PVP and an inorganic salt, the comprehensive effect obtained is better, wherein the reaction The monomer residue is below 3.44ppm, the sulfolane residue is below 121ppm, the yield is above 98.9%, the b value of the reaction color is between 9.16-9.94, and especially when the mass percentage of the inorganic salt in the porogen is further selected to be between 10-40%, the comprehensive effect is optimal; it can be seen from Example 1, Examples 15-16 and Comparative Examples 5-6 that the amount of the porogen added will also significantly affect the performance of the product. When the amount of the porogen added is not within the scope of the present invention, compared with Example 1, the sulfolane residue and the reaction monomer residue in the product obtained in Comparative Examples 5-6 are significantly increased; it can be seen from Example 1 and Comparative Example 7 that when other conventional porogens are used instead of the porogen of the present invention, the effect of the present invention cannot be achieved;

[0095] It can be seen from Example 1, Examples 17-18 and Comparative Examples 3-4 that the addition rate of the mixed solution of the polymerization reaction solution containing the porogen will also have a significant effect on the performance of the product. When the addition rate is not within the scope of the present invention, compared with Example 1, the residual amount of reaction monomers in the product obtained in Comparative Examples 3-4 is significantly increased, the yield also shows a downward trend, and the b value shows an increasing trend. At the same time, the residual sulfolane in the product obtained in Comparative Examples 3-4 is also significantly increased.

[0096] It can be seen from Example 1 and Comparative Example 1 that when conventional purification means are used, but the number of subsequent washings and the amount of water used are consistent with those of the present invention, the residual sulfolane and reactive monomers in the obtained product are also significantly increased, and the b value is also larger; when conventional purification means are used in Comparative Example 2, but the number of washings is increased to 6 times, the performance of the obtained sulfone polymer is still worse than that of the method of the present invention; it can be seen from Example 1 and Comparative Example 8 that when no reaction solvent is added before the porogen is added, the performance of the obtained product also shows a downward trend, especially the residual sulfolane and reactive monomers are significantly increased.

[0097] Effect Example 2

[0098] Effect Example of the Invention The amount of water used in Example 1, Comparative Example 1 and Comparative Example 2 was statistically analyzed, wherein the unit of the amount of water is (ton of water / ton of sulfone polymer), and the statistical results are shown in Table 3;

[0099] Table 3

[0100] Example 1 Comparative Example 1 Comparative Example 2 Purified water usage 20.3 20.3 60.9

[0101] It can be seen from Table 3 that, compared with Comparative Example 2, the amount of water used in the present invention is significantly reduced, and the b value obtained under the amount of water used in Comparative Example 2 is far less than that in Example 1; obviously, the technical solution of the present invention can reduce water consumption and achieve the purpose of energy saving and emission reduction.

[0102] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for purifying a sulfone polymer, characterized in that: The purification method comprises the following steps: The raw materials for synthesizing sulfone polymer are mixed and subjected to polymerization reaction, and when the reaction solution reaches the target viscosity of 100-3000 cps, a polymerization reaction solvent is added to the reaction solution, and then a mixed solution of a porogen and a polymerization reaction solvent is added at a rate of 50-500 g / min and stirred, and then added to water for precipitation, and the precipitate is collected and crushed, washed, and dried to obtain a sulfone polymer; Wherein, based on the total mass of the raw materials for synthesizing the sulfone polymer, the mass percentage of the porogen is 0.1-2%; The porogen is selected from at least one of polyvinyl pyrrolidone, polyethylene glycol or an inorganic salt; The inorganic salt is Zr chloride or copper chloride; In the mixed solution of the porogen and the polymerization reaction solvent, the mass percentage of the porogen is 5-50%; When adding the polymerization reaction solvent to the reaction solution, the mass of the added polymerization reaction solvent is 20-60% of the total mass of the raw materials for synthesizing the sulfone polymer; In the sulfone polymer, the residual reaction monomer was less than 9.86 ppm, and the residual reaction solvent was less than 192 ppm.

2. The purification method according to claim 1, characterized in that The K value of the polyvinyl pyrrolidone is 10-110; And / or, the degree of polymerization of the polyethylene glycol is 300-9000.

3. The purification method according to claim 1, characterized in that The porogen is a mixture of an inorganic salt and polyvinyl pyrrolidone or a mixture of an inorganic salt and polyethylene glycol.

4. The purification method according to claim 3, characterized in that The mass percentage of the inorganic salt is 10-40% based on the porogen.

5. The purification method according to claim 1, characterized in that: The mixed solution of the porogen and the polymerization reaction solvent is added at a rate of 100-300 g / min.

6. The purification method according to claim 1, characterized in that: Based on the total mass of the raw materials for synthesizing the sulfone polymer, the mass percentage of the porogen is 0.5-1%.

7. The purification method according to claim 1, characterized in that: The stirring temperature is 140-180° C., the stirring speed is 200-700 r / min, and the stirring time is 20-40 min.

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