Polyarylethersulfone and preparation method therefor

Abstract

The present invention provides a polyarylethersulfone and a preparation method therefor. The preparation method comprises: mixing a polar aprotic solvent, a bisphenol monomer, and an alkaline substance, heating the mixture, dehydrating same, then cooling same to T1, adding a dihalodiphenylsulfone monomer, and maintaining the temperature at T1 for a first-stage polymerization reaction; and adding a low-polarity solvent, and then heating to T2 for a second-stage polymerization reaction, so as to obtain a polyarylethersulfone. The present invention allows for reduction or partial inhibition of the production of cyclic oligomers during a reaction, so as to obtain a polyarylethersulfone having a narrow molecular weight distribution and a low amount of cyclic polymers.

Description

A polyarylene ether sulfone and its preparation method Technical Field

[0001] This invention relates to a polyarylene ether sulfone and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] Polyarylene ether sulfone (polysulfone) is a high-performance polymer with excellent heat resistance, mechanical properties, and flame retardancy. Due to its favorable properties, it is widely used in automotive, aerospace, medical devices, household appliances, and separation membranes. Currently, industrially produced polysulfone resins mainly include bisphenol A type polysulfone (PSU), polyether sulfone (PES), and polyphenylene sulfone (PPSU). They are generally produced by stepwise polymerization of bisphenol monomers with dichlorodiphenyl sulfone under alkaline conditions via a high-temperature solution method.

[0003] During the solution polymerization of polysulfone, chain cyclization inevitably occurs. The resulting cyclic oligomers cannot further increase their molecular weight, causing the polycondensation reaction to deviate from the classical polycondensation model. This results in a wider molecular weight distribution in the final product, which in turn affects the processing and performance of the resin. Furthermore, these cyclic oligomers deposit on the walls of polysulfone solution storage containers, forming a hard, difficult-to-remove scale. This scale is extremely difficult to dissolve, insoluble in traditional organic solvents, and difficult to remove even at high temperatures of 400°C, severely impacting the storage and use of polysulfone materials.

[0004] Therefore, reducing the content of cyclic oligomers in polysulfone and suppressing cyclization side reactions to improve polysulfone performance is of great significance for broadening the applications of polysulfone materials. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a polyarylene ether sulfone and its preparation method. This method can reduce or partially inhibit the formation of cyclic oligomers during the reaction process, thereby obtaining a polyarylene ether sulfone with a narrow molecular weight distribution and low content of cyclic polymers.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing polyarylene ether sulfone, comprising the following steps:

[0007] After mixing a polar aprotic solvent, bisphenol monomer, and alkaline substance, a protective gas is introduced, the mixture is heated to dehydrate, and then cooled to T1 to add diphenyl sulfone monomer. The first stage of polymerization reaction is carried out while maintaining the temperature at T1.

[0008] After adding a low-polarity solvent, the temperature is raised to T2 to carry out the second stage of polymerization reaction, yielding polyarylether sulfone;

[0009] The low-polarity solvent is selected from one or more combinations of n-hexane, cyclohexane, toluene, ethylbenzene, biphenyl, and diphenyl ether.

[0010] According to a specific embodiment of the present invention, the low polarity solvent is selected from one or more combinations of n-hexane, cyclohexane, toluene, and biphenyl.

[0011] In this invention, a low-polarity solvent is added during the second-stage polymerization reaction (high-temperature section) to reduce the solvent polarity of the reaction system. The addition of the low-polarity solvent not only affects the reaction activity and selectivity but also changes the solubility of the product in the mixed system. Therefore, the effect is optimal when the amount of mixed solvent reaches a certain preferred equilibrium value. The second-stage polymerization chain growth reaction is carried out efficiently at a higher temperature to further suppress the cyclization reaction, thereby improving the selectivity of the linear chain growth reaction relative to the cyclization reaction, reducing the formation of low-molecular-weight cyclic oligomers in the polymer, and reducing the molecular weight distribution of the polymer product.

[0012] According to a specific embodiment of the present invention, preferably, the molar ratio of the polar aprotic solvent, bisphenol monomer, basic substance, and diphenyl sulfone monomer is (5-9):1:(1-1.1):(1-1.05).

[0013] According to a specific embodiment of the present invention, preferably, the content of the low-polarity solvent is 5 wt.% to 25 wt.%, based on a total weight of 100 wt.% of the polar aprotic solvent and the low-polarity solvent.

[0014] According to a specific embodiment of the present invention, preferably, the bisphenol monomer is selected from one or more combinations of bisphenol A, bisphenol S, and biphenyl hydroquinone.

[0015] According to a specific embodiment of the present invention, preferably, the diphenyl sulfone monomer is a dihalogenated diphenyl sulfone monomer, specifically selected from one or more combinations of 4,4′-dichlorodiphenyl sulfone, 4,4′-difluorodiphenyl sulfone and 4,4′-dibromodiphenyl sulfone, and more preferably 4,4′-dichlorodiphenyl sulfone.

[0016] According to a specific embodiment of the present invention, preferably, the polar aprotic solvent is selected from one or more combinations of N-methylpyrrolidone, dimethylformamide, dimethylacetamide, DMSO, and sulfolane.

[0017] According to a specific embodiment of the present invention, preferably, the alkaline substance is selected from one or more combinations of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate; more preferably, sodium carbonate and / or potassium carbonate.

[0018] According to a specific embodiment of the present invention, preferably, T2-T1 ≥ 20℃.

[0019] According to a specific embodiment of the present invention, preferably, T1 is 150-200°C, more preferably 150-180°C. If the reaction temperature of T1 is too low, the bisphenol salt cannot be fully dissolved, which will affect the reaction efficiency and reaction selectivity. If the reaction temperature of T1 is too high, a large amount of cyclic oligomers will be generated in the first stage of polymerization.

[0020] According to a specific embodiment of the present invention, preferably, the T2 temperature is 180-240°C, more preferably 180-220°C. If the reaction temperature of T2 is too low, the molecular chain growth rate is too slow, requiring a long reaction time; if the reaction temperature of T2 is too high, side reactions such as end-capping and degradation will occur, making it difficult to obtain high molecular weight products.

[0021] According to a specific embodiment of the present invention, preferably, the heating rate of the second-stage polymerization reaction is 0.4-1℃ / min.

[0022] According to a specific embodiment of the present invention, preferably, the first stage polymerization reaction is carried out to the extent that the conversion rate of phenolic hydroxyl groups in the bisphenol monomer reaches 95% or more, preferably 98% or more; the second stage polymerization reaction is carried out to the extent that the conversion rate of phenolic hydroxyl groups in the bisphenol monomer reaches 99.2% or more, preferably 99.5%-99.8%, and the molecular weight will not increase significantly if the reaction time is further extended, but the content of cyclic oligomers will increase significantly.

[0023] According to a specific embodiment of the present invention, preferably, after the conversion rate of the phenolic hydroxyl groups in the bisphenol monomer reaches 99.5% or more in the second stage, the molecular weight is basically stable, and the viscosity of the reaction solution no longer increases, a capping agent is introduced, followed by dilution of the reaction solution with a polar aprotic solvent. The solution is then cooled to room temperature, filtered to remove solids, vacuum filtered, and dried to obtain the polyarylene ether sulfone. The added polar aprotic solvent can be one or a combination of two or more of N-methylpyrrolidone, dimethylformamide, dimethylacetamide, DMSO, and sulfolane.

[0024] According to a specific embodiment of the present invention, preferably, a polar aprotic solvent, bisphenol monomer, and alkaline substance are mixed, a protective gas is introduced, and the temperature is raised to 180-210°C for dehydration, preferably 200°C; then the temperature is lowered to T1, diphenyl sulfone monomer is added, and the temperature is maintained at T1 to carry out the first stage polymerization reaction; then a low-polarity organic solvent is added, and the temperature is raised to T2 to carry out the second stage polymerization reaction.

[0025] According to a specific embodiment of the present invention, preferably, the capping agent is a halogenated aliphatic hydrocarbon and / or an aromatic compound, selected from one or more combinations of chloromethane, chloroethane, chloropropane, monochlorophenyl sulfone, 4-fluororesorcinol, and pentafluorophenol.

[0026] Secondly, the present invention provides a polyarylene sulfone prepared by the method described above.

[0027] According to a specific embodiment of the present invention, preferably, the weight-average molecular weight of the polyarylether sulfone is 40,000-73,000 g / mol.

[0028] According to a specific embodiment of the present invention, preferably, the molecular weight distribution of the polyarylether sulfone is 2.0-2.9.

[0029] According to a specific embodiment of the present invention, preferably, the content of cyclic oligomers in the polyarylether sulfone is ≤1.2wt%.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The preparation method of the present invention involves pre-dehydration treatment before the reaction. In the first stage of polymerization, the selectivity of the chain growth reaction relative to the cyclization reaction is improved by controlling the reaction temperature and substrate concentration, thereby inhibiting the formation of cyclic dimers. After the bisphenol monomers in the first stage of polymerization are basically converted, a low-polarity solvent is added to reduce the solvent polarity of the reaction system, and the second stage of polymerization chain growth reaction is carried out at a higher temperature to continue to inhibit the cyclization reaction while ensuring the reaction rate, thereby reducing the formation of low molecular weight cyclic oligomers in the polymerization product. Detailed Implementation

[0032] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0033] Example 1:

[0034] This embodiment provides a method for preparing polyarylene ether sulfone, comprising the following steps:

[0035] In a 3L stainless steel reactor equipped with a thermometer, air inlet pipe, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, and 595g (6mol) of N-methylpyrrolidone were added. Nitrogen gas was continuously introduced into the reactor for 15 minutes with stirring, and the temperature was gradually increased to 200℃ to remove moisture. After cooling to 160℃, 287.2g (1mol) of 4,4'-dichlorodiphenyl sulfone was added. The reactor was sealed and the first stage of polymerization was carried out at 160℃ for 4 hours.

[0036] Add 84g (1mol) of cyclohexane, then raise the temperature to 210℃ at 1℃ / min for the second stage of polymerization, and keep the temperature for 4 hours; cool down to 160℃, introduce 500mL of chloromethane gas and react for 15min, then add 595g (6mol) of N-methylpyrrolidone, and then cool down to room temperature.

[0037] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-1.

[0038] The molecular weight and molecular weight distribution of the polyarylether sulfone obtained in this embodiment were determined by gel permeation chromatography (GPC) using dimethylacetamide as solvent and narrow-distribution polystyrene as standard. The content of cyclic dimers was determined by ultra-high performance polymer chromatography (APC) using N,N'-dimethylformamide as solvent. The test results showed that PSU-1 had a weight-average molecular weight of 65,000, a molecular weight distribution index of 2.6, and a cyclic dimer content of 1.0 wt.%, as shown in Table 1.

[0039] Example 2:

[0040] This embodiment provides a method for preparing polyarylene ether sulfone. The only difference between Example 2 and Example 1 is that:

[0041] After the first stage of polymerization, 168g (2mol) of cyclohexane was added, and then the temperature was increased to 210℃ at 1℃ / min for the second stage of polymerization. The reaction was maintained at this temperature for 6 hours. The temperature was then lowered to 160℃, and 500mL of chloromethane gas was introduced and reacted for 15min. Then, 595g (6mol) of N-methylpyrrolidone was added, and the temperature was lowered to room temperature.

[0042] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-2.

[0043] The test results show that PSU-2 has a weight-average molecular weight of 64,000, a molecular weight distribution index of 2.4, and a cyclic dimer content of 0.85 wt.%. The test results are shown in Table 1.

[0044] Example 3:

[0045] This embodiment provides a method for preparing polyarylene ether sulfone. The only difference between Example 3 and Example 1 is that:

[0046] After the first stage of polymerization, 92 g (1 mol) of toluene was added, and then the temperature was increased to 210 °C at 1 °C / min for the second stage of polymerization, and the reaction was maintained at this temperature for 4 hours. The temperature was then lowered to 160 °C, 500 mL of chloromethane gas was introduced, and the reaction was carried out for 15 min. Then, 595 g (6 mol) of N-methylpyrrolidone was added, and the temperature was lowered to room temperature.

[0047] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-3.

[0048] The test results show that PSU-3 has a weight-average molecular weight of 62,000, a molecular weight distribution index of 2.8, and a cyclic dimer content of 1.1 wt.%. The test results are shown in Table 1.

[0049] Example 4:

[0050] This embodiment provides a method for preparing polyarylene ether sulfone. The only difference between Example 4 and Example 1 is that:

[0051] After the first stage of polymerization, 170 g (1 mol) of biphenyl was added, and then the temperature was increased to 210 °C at 1 °C / min for the second stage of polymerization, and the reaction was maintained at this temperature for 4 hours. The temperature was then lowered to 160 °C, 500 mL of chloromethane gas was introduced, and the reaction was carried out for 15 min. Then, 595 g (6 mol) of N-methylpyrrolidone was added, and the temperature was lowered to room temperature.

[0052] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-4.

[0053] The test results show that PSU-4 has a weight-average molecular weight of 67,000, a molecular weight distribution index of 2.9, and a cyclic dimer content of 1.2 wt.%. The test results are shown in Table 1.

[0054] Example 5:

[0055] This embodiment provides a method for preparing polyarylene ether sulfone. The only difference between Example 5 and Example 1 is that:

[0056] In a 3L stainless steel reactor equipped with a thermometer, air inlet pipe, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, and 595g (6mol) of N-methylpyrrolidone were added. Nitrogen gas was continuously introduced into the reactor for 15 minutes with stirring, and the temperature was gradually increased to 200℃ to remove moisture. After cooling to 160℃, 290g (1.01mol) of 4,4'-dichlorodiphenyl sulfone was added.

[0057] The final polyarylene ether sulfone (PSU-5) had a weight-average molecular weight of 42,000, a molecular weight distribution index of 2.4, and a cyclic dimer content of 0.88 wt.%. The test results are shown in Table 1.

[0058] Example 6:

[0059] This embodiment provides a method for preparing polyarylene ether sulfone, comprising the following steps:

[0060] In a 3L stainless steel reactor equipped with a thermometer, air inlet pipe, and water separator, 250.3g (1mol) of bisphenol S, 152g (1.1mol) of powdered potassium carbonate, and 595g (6mol) of N-methylpyrrolidone were added. Nitrogen gas was continuously introduced into the reactor for 15 minutes with stirring, and the temperature was gradually increased to 200℃ to remove moisture. After cooling to 160℃, 287.2g (1mol) of 4,4'-dichlorodiphenyl sulfone was added, and the first stage polymerization reaction was carried out at 160℃ for 6 hours.

[0061] Add 84g (1mol) of n-hexane, then raise the temperature to 210℃ at 1℃ / min for the second stage of polymerization, and keep the temperature for 4 hours; cool down to 160℃, introduce 500mL of chloromethane gas and react for 15min, then add 595g (6mol) of N-methylpyrrolidone, and then cool down to room temperature.

[0062] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PES-6.

[0063] The test results show that PES-6 has a weight-average molecular weight of 52,000, a molecular weight distribution index of 2.0, and a cyclic dimer content of 0.7 wt.%. The test results are shown in Table 1.

[0064] Example 7

[0065] This embodiment provides a method for preparing polyarylene ether sulfone. The only difference between Example 7 and Example 1 is that:

[0066] After adding 4,4'-dichlorodiphenyl sulfone, the first stage of polymerization was carried out at 180°C and the reaction was maintained at this temperature for 3 hours.

[0067] Add 84 g (1 mol) of cyclohexane, then raise the temperature to 220 °C at 0.4 °C / min for the second stage of polymerization, and maintain the temperature for 4 hours. Cool down to 160 °C, introduce 500 mL of chloromethane gas and react for 15 min, then add 595 g (6 mol) of N-methylpyrrolidone, and then cool to room temperature.

[0068] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-7.

[0069] The test results show that PSU-7 has a weight-average molecular weight of 72,000, a molecular weight distribution index of 2.9, and a cyclic dimer content of 1.15 wt.%. The test results are shown in Table 1.

[0070] Comparative Example 1:

[0071] This comparative example provides a method for preparing polyarylene ether sulfone. The only difference between Comparative Example 1 and Example 1 is that:

[0072] After the first stage of polymerization, 99g (1mol) of NMP was added, and then the temperature was increased to 210℃ at 1℃ / min for the second stage of polymerization. The reaction was maintained at this temperature for 4 hours. The temperature was then lowered to 160℃, and 500mL of chloromethane gas was introduced and reacted for 15min. Then, 595g (6mol) of N-methylpyrrolidone was added, and the temperature was lowered to room temperature.

[0073] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylene ether sulfone PSU-1-D.

[0074] The test results show that PSU-1-D has a weight-average molecular weight of 68,000, a molecular weight distribution index of 3.2, and a cyclic dimer content of 1.4 wt.%. The test results are shown in Table 1.

[0075] Comparative Example 2:

[0076] This comparative example provides a method for preparing polyarylene ether sulfone, comprising the following steps:

[0077] In a 3L stainless steel reactor equipped with a thermometer, air inlet pipe, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, and 595g (6mol) of N-methylpyrrolidone were added. Nitrogen gas was continuously introduced into the reactor for 15 minutes with stirring, and the temperature was gradually increased to 200℃ to remove moisture. After cooling to 160℃, 287.2g (1mol) of 4,4'-dichlorodiphenyl sulfone and 84g (1mol) of cyclohexane were added. The reactor was sealed, and the temperature was increased to 210℃ at a rate of 1℃ / min for polymerization. The reaction was maintained at this temperature for 12 hours.

[0078] The temperature was lowered to 160℃, 500mL of chloromethane gas was introduced and reacted for 15min, then 595g (6mol) of N-methylpyrrolidone was added, and the temperature was lowered to room temperature.

[0079] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylene ether sulfone PSU-2-D.

[0080] The test results show that PSU-2-D has a weight-average molecular weight of 70,000, a molecular weight distribution index of 3.6, and a cyclic dimer content of 1.6 wt.%. The test results are shown in Table 1.

[0081] Comparative Example 3:

[0082] This comparative example provides a method for preparing polyarylene ether sulfone. The only difference between Comparative Example 3 and Example 1 is that:

[0083] After dehydration, the temperature was lowered to 140℃, and 287.2g (1mol) of 4,4'-dichlorodiphenyl sulfone was added. The mixture was sealed and kept at 140℃ for the first stage of polymerization reaction for 4 hours.

[0084] Add 84g (1mol) of cyclohexane, then raise the temperature to 210℃ at 1℃ / min to carry out the second stage of polymerization reaction, and keep the reaction at this temperature for 4 hours; cool down to 160℃, introduce 500mL of chloromethane gas and react for 15min, then add 595g (6mol) of N-methylpyrrolidone, and then cool down to room temperature.

[0085] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain PSU-3-D.

[0086] The test results show that PSU-3-D has a weight-average molecular weight of 58,000, a molecular weight distribution index of 3.1, and a cyclic dimer content of 1.35 wt.%. The test results are shown in Table 1.

[0087] Comparative Example 4:

[0088] This comparative example provides a method for preparing polyarylene ether sulfone, comprising the following steps:

[0089] In a 3L stainless steel reactor equipped with a thermometer, air inlet pipe, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, and 694g (7mol) of N-methylpyrrolidone were added. Nitrogen gas was continuously introduced into the reactor for 15 minutes with stirring, and the temperature was gradually increased to 200℃ to remove moisture. After cooling to 160℃, 287.2g (1mol) of 4,4'-dichlorodiphenyl sulfone was added. The reactor was sealed, and the temperature was increased to 210℃ at a rate of 1℃ / min for polymerization. The reaction was maintained at this temperature for 4 hours. After cooling to 160℃, 500mL of chloromethane gas was introduced and reacted for 15 minutes. Then, 595g (6mol) of N-methylpyrrolidone was added, and the reactor was cooled to room temperature.

[0090] The insoluble matter in the reaction solution was removed by filtration, and then slowly added to 10 times its weight of ethanol under stirring to precipitate. After filtration, the filter cake was mixed with 6 times its weight of ethanol and stirred for 1 hour before filtration. The filter cake was then boiled and washed twice with deionized water and finally dried to obtain polyarylether sulfone PSU-4-D.

[0091] The test results show that PSU-4-D has a weight-average molecular weight of 63,000, a molecular weight distribution index of 3.4, and a cyclic dimer content of 1.5 wt.%. The test results are shown in Table 1.

[0092] Table 1

[0093] As can be seen from Examples 1-7 in Table 1, the polyarylether sulfone obtained by the present invention has a narrow molecular weight distribution and a low content of cyclic dimers, with the content of cyclic dimers reaching as low as 0.7 wt.%.

[0094] In Comparative Example 1, no low-polarity solvent (NMP) was added during the second stage of polymerization. Compared with Example 1, the molecular weight distribution increased from 2.6 to 3.2, and the cyclic dimer content increased from 1.0 wt.% to 1.4 wt.%.

[0095] In Comparative Example 2, after adding 4,4'-dichlorodiphenyl sulfone monomer and a low-polarity solvent (cyclohexane), the temperature was directly raised to a high-temperature range for polymerization. At high substrate concentrations and high polymerization temperatures, the added low-polarity solvent could not effectively inhibit the formation of cyclic oligomers.

[0096] The temperature of the first-stage polymerization reaction in Comparative Example 3 was 140°C, which is outside the range of this invention. Therefore, the resulting polyarylether sulfone had a wider molecular weight distribution and a higher content of cyclic dimers.

[0097] In Comparative Example 4, no low-polarity solvent was added, and after adding 4,4'-dichlorodiphenyl sulfone monomer, the temperature was directly raised to a high-temperature range for polymerization. The resulting polyarylene ether sulfone had a molecular weight distribution of 3.4 and a cyclic dimer content of 1.5 wt.%. In contrast, in Example 1, the polymerization reaction was divided into two stages, and a low-polarity solvent was added during the second stage of polymerization. The resulting polyarylene ether sulfone had a molecular weight distribution that decreased from 3.4 to 2.6 and a cyclic dimer content that decreased from 1.5 wt.% to 1.0 wt.%.

Claims

1. A process for the preparation of a polyarylene ether sulfone, wherein, Includes the following steps: After mixing a polar aprotic solvent, bisphenol monomer, and alkaline substance, a protective gas is introduced, the mixture is heated to dehydrate, and then cooled to T1 to add diphenyl sulfone monomer. The first stage of polymerization reaction is carried out while maintaining the temperature at T1. After adding a low-polarity solvent, the temperature is raised to T2 to carry out the second stage of polymerization reaction, yielding polyarylether sulfone; The low-polarity solvent is selected from one or more combinations of n-hexane, cyclohexane, toluene, ethylbenzene, biphenyl, and diphenyl ether.

2. The production method according to claim 1, wherein The molar ratio of the polar aprotic solvent, bisphenol monomer, basic substance, and diphenyl sulfone monomer is (5-9):1:(1-1.1):(1-1.05).

3. The production method according to claim 1, wherein, The content of the low-polarity solvent is 5 wt.% to 25 wt.%, based on a total weight of 100 wt.% of the polar aprotic solvent and the low-polarity solvent.

4. The production method according to claim 1 or 2, wherein The bisphenol monomer is selected from one or more of bisphenol A, bisphenol S, and biphenyl.

5. The production method according to claim 1 or 2, wherein The dihalodiphenyl sulfone monomer is selected from one or a combination of two or more of 4,4′-dichlorodiphenyl sulfone, 4,4′-difluorodiphenyl sulfone, and 4,4′-dibromodiphenyl sulfone.

6. The production method according to claim 1, wherein The polar aprotic solvent is selected from one or more of N-methylpyrrolidone, dimethylformamide, dimethylacetamide, DMSO, and sulfolane.

7. The production method according to claim 1, wherein The alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate.

8. The production method according to claim 1, wherein The T2-T1 ≥ 20℃.

9. The production method according to claim 1 or 8, wherein The T1 is 150-200℃; And / or, the T2 is 180-240℃.

10. The production method according to claim 9, wherein The T1 is 150-180℃; And / or, the T2 is 180-220℃.

11. The production method according to claim 1, wherein The first stage of polymerization proceeds until the conversion rate of phenolic hydroxyl groups in the bisphenol monomer reaches more than 95%.

12. The method of making according to claim 11, wherein, The first stage of polymerization proceeds until the conversion rate of phenolic hydroxyl groups in the bisphenol monomer reaches over 98%.

13. The method of producing according to claim 1, wherein, The heating rate for the second-stage polymerization reaction is 0.4-1℃ / min.

14. The method of producing according to claim 1, wherein, The second stage of polymerization proceeds until the conversion rate of the phenolic hydroxyl end groups in the bisphenol monomer reaches over 99.2%.

15. The method of manufacturing according to claim 14, wherein, The second stage of polymerization proceeds until the conversion rate of the phenolic hydroxyl end groups in the bisphenol monomer reaches 99.5%-99.8%.

16. The method of producing according to claim 1, wherein, After the second stage of polymerization is completed, a capping agent is introduced, followed by the addition of a polar aprotic solvent. The mixture is cooled to room temperature, and the solid in the system is removed by filtration. After vacuum filtration and drying, the polyarylether sulfone is obtained.

17. A polyarylene sulfone prepared by a method according to any one of claims 1-16.

18. The poly(arylene ether sulfone) of claim 17, wherein, The weight-average molecular weight of the polyarylether sulfone is 40,000-73,000 g / mol.

19. The poly(arylene ether sulfone) of claim 17, wherein, The molecular weight distribution of the polyarylether sulfone is 2.0-2.

9.

20. The poly(arylene ether sulfone) of claim 17, wherein, The content of cyclic oligomers in the polyarylether sulfone is ≤1.2wt%.

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