A polyethersulfone composition, a method of making the same, and articles

Abstract

The present application relates to the technical fields of high polymer material synthesis, and particularly relates to a polyether sulfone composition, a preparation method thereof and an article, by controlling the content of N-methyl-4-aminobutyric acid and alkali metal salt thereof in a range of greater than 0 and less than or equal to 50 ppm, the poly(N-methyl-4-aminobutyric acid) amide oligomer generated by self-polymerization of N-methyl-4-aminobutyric acid at high temperature is reduced, the heat resistance of the polyether sulfone is significantly improved, the yellowness index of the polyether sulfone is effectively reduced, the optical performance of the polyether sulfone is improved, the application performance of the polyether sulfone in the high temperature field is improved, and the polyether sulfone is particularly suitable for application occasions requiring high transparency and good color.

Description

Technical Field

[0001] This invention relates to the field of polymer material synthesis technology, specifically to a polyethersulfone composition, its preparation method, and the product thereof. Background Technology

[0002] Polyethersulfone is a special engineering plastic with excellent comprehensive properties, including good thermal stability, mechanical properties, chemical stability and biocompatibility. It is widely used in aerospace, electronics, automotive, military and other fields, as well as medical fields such as water treatment and hemodialysis.

[0003] As downstream applications continue to demand higher performance from materials, especially in high-temperature environments such as optical materials and medical devices, higher standards are being set for the heat resistance of polyethersulfone.

[0004] In the prior art, the heat resistance of polyethersulfone materials is usually improved by filling the polyethersulfone matrix with inorganic fillers or by blending it with another polymer with better heat resistance. However, some added materials affect the color of the product due to their inconsistency with the refractive index of polyethersulfone, resulting in an increase in the yellowness index. Summary of the Invention

[0005] This invention provides a polyethersulfone composition, its preparation method, and the product thereof, aiming to solve the problem that the yellowness index of the product increases when the heat resistance of polyethersulfone is improved by adding external materials. The polyethersulfone composition provided by this invention can significantly increase the heat distortion temperature and reduce the yellowness index.

[0006] In a first aspect, this application provides a polyethersulfone composition comprising: (a) Polyethersulfone; (b) N-methyl-4-aminobutyric acid and its alkali metal salts; Specifically, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is less than or equal to 50 ppm, and the content of N-methyl-4-aminobutyric acid and its alkali metal salt is not 0. Preferably, it is 1-15 ppm.

[0007] In some embodiments, the polyethersulfone has a weight-average molecular weight of 50,000-150,000 g / mol. Preferably, it is between 60,000 and 100,000 g / mol.

[0008] In some embodiments, the polyethersulfone has a molecular weight distribution of less than 2.0. Preferably, it is 1.5 to 1.9.

[0009] In some embodiments, the polyethersulfone content in the polyethersulfone composition is greater than or equal to 99.5%.

[0010] In some embodiments, the heat distortion temperature of the polyethersulfone composition is not less than 215°C, measured according to ASTM D648 on a 3.2 mm thick molding strip under a load of 1.82 MPa.

[0011] In some embodiments, the yellowness index of the polyethersulfone composition is less than 10.

[0012] In some embodiments, the alkali metal salt of N-methyl-4-aminobutyric acid includes sodium N-methyl-4-aminobutyrate and / or potassium N-methyl-4-aminobutyrate.

[0013] Secondly, this application also provides a method for preparing any of the above-described polyethersulfone compositions, comprising the following steps: A monomer containing a bisphenol structure, 4,4'-dichlorodiphenyl sulfone, a salt-forming agent and a reaction solvent are mixed, and the reaction product is obtained through a salt-forming reaction, a polymerization reaction and an end-capping treatment. The reaction product was washed and dried using a weak alkali and water as detergents to obtain a polyethersulfone composition.

[0014] In some embodiments, the salt-forming agent is selected from alkali metal carbonates. Optionally, the alkali metal carbonate is selected from one or more of sodium carbonate and potassium carbonate.

[0015] In some embodiments, the weak base is selected from alkali metal bicarbonates; optionally, the alkali metal bicarbonate is selected from one or more of sodium bicarbonate and potassium bicarbonate.

[0016] In some embodiments, the reaction solvent is N-methylpyrrolidone.

[0017] In some embodiments, the monomer containing the bisphenol structure is bisphenol S.

[0018] In some embodiments, the capping agent is one or more of chloromethane and 4-chlorophenylsulfone.

[0019] In some embodiments, the molar ratio of the bisphenol-containing monomer to 4,4'-dichlorodiphenyl sulfone is 1:1.0 to 1:1.03.

[0020] In some embodiments, the molar ratio of the bisphenol-containing monomer to the salt-forming agent is 1:1.05~1.3.

[0021] In some embodiments, the mass of the reaction solvent is 20% to 50% of the total mass of the bisphenol-containing monomer, 4,4'-dichlorodiphenyl sulfone, salt-forming agent, and reaction solvent.

[0022] In some embodiments, the molar ratio of the capping agent to the monomer containing the bisphenol structure is 0.02 to 0.1:1.

[0023] In some embodiments, the polymerization reaction and the end-capping treatment are further separated by a step of diluting the reaction product with a diluting solvent.

[0024] In some embodiments, the mass ratio of the weak alkali in the detergent to the monomer containing the bisphenol structure is 30-5000:20000-25000.

[0025] In some embodiments, the mass ratio of the weak base to the volume of water is 0.15~25g:1L.

[0026] In some embodiments, the salt-forming reaction is carried out by reflux to remove water from the reaction system.

[0027] In some embodiments, the salt formation reaction is carried out at a temperature of 140°C-180°C for 2-6 hours.

[0028] In some embodiments, the polymerization reaction is carried out at a temperature of 190°C-205°C for 2 hours to 12 hours.

[0029] In some embodiments, the end-sealing process is performed at a temperature of 120°C-160°C.

[0030] In some embodiments, the first washing includes solid-liquid separation following boiling and / or ultrasonic treatment.

[0031] In some embodiments, the reaction product is further subjected to precipitation followed by solid-liquid separation, crushing, and / or drying before the first washing.

[0032] In some implementations, the first washing cycle is 1 to 5 times.

[0033] In some embodiments, the first wash is followed by a second wash using water as the detergent.

[0034] In some embodiments, the power of the ultrasonic treatment is 20-800W.

[0035] In some embodiments, the cooking temperature is 80-120°C.

[0036] In some embodiments, the ultrasonic treatment and / or steaming treatment time is 0.5-12 hours.

[0037] In some embodiments, the first wash includes simultaneous steaming and ultrasonic treatment.

[0038] Thirdly, this application provides an article comprising any of the polyethersulfone compositions described above or a polyethersulfone composition prepared by any of the preparation methods described above.

[0039] In some embodiments, the article is an optical article or a medical device.

[0040] The technical solution of this invention has the following advantages: 1. Research has found that the five-membered lactam bond (CN bond) of N-methylpyrrolidone (NMP) in OH... - Under attack, ring-opening hydrolysis occurs, generating N-methyl-4-aminobutyric acid (4-methylaminobutyric acid). This product reacts immediately with a salt-forming agent in an alkaline system to form potassium or sodium N-methyl-4-aminobutyrate, both of which are hallmark products of NMP hydrolysis. This not only leads to NMP depletion but also affects the performance of polyethersulfone (PES) because the product can undergo self-polymerization at high temperatures, forming poly(N-methyl-4-aminobutyric acid) amide oligomers. These oligomers reduce the heat resistance of PES, affecting its application in high-temperature applications, and also reduce the optical properties of the material, such as transparency and color.

[0041] The polyethersulfone composition provided by this invention comprises: (a) polyethersulfone; (b) N-methyl-4-aminobutyric acid and its alkali metal salt; wherein, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is less than or equal to 50 ppm, and the content of N-methyl-4-aminobutyric acid and its alkali metal salt is not 0. By controlling the content of N-methyl-4-aminobutyric acid and its alkali metal salt within the above range, the self-polymerization of poly(N-methyl-4-aminobutyric acid) amide oligomers at high temperatures is reduced, which not only significantly improves the heat resistance of polyethersulfone, but also effectively reduces the yellowness index of polyethersulfone, improves the optical properties of polyethersulfone, thereby improving the application performance of polyethersulfone in high-temperature fields, and is particularly suitable for applications requiring high transparency and good color.

[0042] 2. The polyethersulfone composition preparation method provided by this invention is simple to operate and easy to scale up for industrial production. It eliminates the need for high-boiling-point, highly toxic solvents such as dimethyl sulfone, thus meeting green and environmentally friendly requirements. Furthermore, the purification process is simple, eliminating the need for precipitation with precipitating agents or low-temperature precipitation to remove impurities. Ultrasonic superimposed cooking treatment improves washing efficiency, reduces the number of washing cycles, and lowers energy and water consumption, also meeting green and environmentally friendly requirements.

[0043] 3. The polyethersulfone composition preparation method provided by the present invention uses a weak alkali and water as detergents to wash the reaction product. The weak alkali can efficiently remove N-methyl-4-aminobutyric acid and its alkali metal salts encapsulated in polyethersulfone, significantly reducing the content of N-methyl-4-aminobutyric acid and its alkali metal salts. This effectively solves the problems of high energy consumption, high cost and large environmental pollution caused by the multiple high-temperature washing methods in the prior art. Detailed Implementation

[0044] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0045] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0046] Therefore, in a first aspect, this application provides a polyethersulfone composition comprising: (a) Polyethersulfone; (b) N-methyl-4-aminobutyric acid and its alkali metal salts; Specifically, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is less than or equal to 50 ppm, and the content of N-methyl-4-aminobutyric acid and its alkali metal salt is not zero. For example, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is 0.5 ppm, 1 ppm, 2 ppm, 5 ppm, 10 ppm, 15 ppm, 20 ppm, 25 ppm, 30 ppm, 35 ppm, 40 ppm, 45 ppm, 50 ppm, or within any two of the above values. Preferably, it is 1-15 ppm.

[0047] The term “N-methyl-4-aminobutyric acid and its alkali metal salts” refers to N-methyl-4-aminobutyric acid and its alkali metal salts.

[0048] In some embodiments, the alkali metal salt of N-methyl-4-aminobutyric acid includes sodium N-methyl-4-aminobutyrate and / or potassium N-methyl-4-aminobutyrate.

[0049] The term "content of N-methyl-4-aminobutyric acid and its alkali metal salt" refers to the total content of N-methyl-4-aminobutyric acid and its alkali metal salt in the polyethersulfone composition.

[0050] In some embodiments, the polyethersulfone has a weight-average molecular weight of 50,000-150,000 g / mol. For example, the polyethersulfone has a weight-average molecular weight of 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 110,000 g / mol, 120,000 g / mol, 130,000 g / mol, 140,000 g / mol, 150,000 g / mol, or within any two of the above values. Preferably, it is between 60,000 and 100,000 g / mol.

[0051] In some embodiments, the polyethersulfone has a molecular weight distribution of less than 2.0. For example, the polyethersulfone has a molecular weight distribution of 1.9, 1.8, 1.7, 1.6, 1.5, or within any two of these values. Preferably, it is 1.5 to 1.9.

[0052] In some embodiments, the polyethersulfone content in the polyethersulfone composition is greater than or equal to 99.5%.

[0053] In some embodiments, the heat distortion temperature of the polyethersulfone composition is not less than 215°C, measured according to ASTM D648 on a 3.2 mm thick molding strip under a load of 1.82 MPa. For example, the heat distortion temperature of the polyethersulfone composition is 215°C, 216°C, 218°C, 220°C, 221°C, 222°C, 223°C, 224°C, 225°C, or within any two of these values.

[0054] In some embodiments, the yellowness index of the polyethersulfone composition is less than 10. For example, the yellowness index is 7, 7.5, 8, 8.5, 9, 9.5, 9.8, or within any two of the above values.

[0055] Secondly, this application also provides a method for preparing any of the above-described polyethersulfone compositions, comprising the following steps: A monomer containing a bisphenol structure, 4,4'-dichlorodiphenyl sulfone, a salt-forming agent and a reaction solvent are mixed, and the reaction product is obtained through a salt-forming reaction, a polymerization reaction and an end-capping treatment. The reaction product was washed for the first time using a weak alkali and water as detergents to obtain a polyethersulfone composition.

[0056] In some embodiments, the salt-forming agent is selected from alkali metal carbonates. Optionally, the alkali metal carbonate is selected from one or more of sodium carbonate and potassium carbonate.

[0057] For example, when sodium carbonate is used as the salt-forming agent, the polyethersulfone composition accordingly contains sodium N-methyl-4-aminobutyrate. When potassium carbonate is used as the salt-forming agent, the polyethersulfone composition accordingly contains potassium N-methyl-4-aminobutyrate.

[0058] In this application, during the first wash, the weak base and water can be mixed separately with the reaction product, or the weak base and water can be mixed first to form an aqueous solution containing the weak base before being mixed with the reaction product.

[0059] In some embodiments, the weak base is selected from alkali metal bicarbonates; optionally, the alkali metal bicarbonate is selected from one or more of sodium bicarbonate and potassium bicarbonate.

[0060] In some embodiments, the reaction solvent is N-methylpyrrolidone.

[0061] In some embodiments, the monomer containing the bisphenol structure is bisphenol S.

[0062] In some embodiments, the capping agent is one or more of chloromethane and 4-chlorophenylsulfone.

[0063] In some embodiments, the molar ratio of the bisphenol-containing monomer to 4,4'-dichlorodiphenyl sulfone is 1:1.0 to 1:1.03. For example, the molar ratio of the bisphenol-containing monomer to 4,4'-dichlorodiphenyl sulfone is 1:1.0, 1:1.01, 1:1.02, 1:1.03, or within any two of these values.

[0064] In some embodiments, the molar ratio of the bisphenol-containing monomer to the salt-forming agent is 1:1.05 to 1.3. For example, the molar ratio of the bisphenol-containing monomer to the salt-forming agent is 1:1.05, 1:1.08, 1:1.1, 1:1.12, 1:1.15, 1:1.2, 1:1.25, 1.3, or within any two of the above values.

[0065] In some embodiments, the mass of the reaction solvent is 20%-50% of the total mass of the bisphenol-containing monomer, 4,4'-dichlorodiphenyl sulfone, salt-forming agent, and reaction solvent. For example, the mass of the reaction solvent is 20%, 25%, 30%, 35%, 40%, 45%, 50%, or within any two of the above values, of the total mass of the bisphenol-containing monomer, 4,4'-dichlorodiphenyl sulfone, salt-forming agent, and reaction solvent.

[0066] In some embodiments, the molar ratio of the capping agent to the bisphenol-containing monomer is 0.02 to 0.1:1. For example, the molar ratio of the capping agent to the bisphenol-containing monomer is 0.02:1, 0.04:1, 0.06:1, 0.08:1, 0.1:1, or within any two of the above values.

[0067] In some embodiments, a step of diluting the reaction product with a diluting solvent is included between the polymerization reaction and the end-capping treatment. The diluting solution may be N-methylpyrrolidone, and the mass of the diluting solvent is 20% to 50% of the total mass of the bisphenol-containing monomer, 4,4'-dichlorodiphenyl sulfone, the salt-forming agent, and the diluting solvent.

[0068] In some embodiments, the mass ratio of the weak base to the volume of water is 0.15 to 25 g: 1 L. Examples of such ratios include 0.15: 1 L, 2.5 g: 1 L, 2.6 g: 1 L, 2.7 g: 1 L, 2.8 g: 1 L, 2.9 g: 1 L, 3 g: 1 L, 25 g: 1 L, or any combination of the above values.

[0069] In some embodiments, the salt-forming reaction is carried out by reflux to remove water from the reaction system.

[0070] In some embodiments, the salt-forming reaction is carried out at a temperature of 140°C-180°C and for a reaction time of 2-6 hours. The salt-forming reaction temperature can be, for example, 140°C, 150°C, 160°C, 170°C, 180°C, etc., and can be specifically set according to the boiling point of the reaction solvent, for example, below the boiling point of the reaction solvent; the reaction time can be, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, etc., specifically based on the condition that no more water is produced.

[0071] In some embodiments, the polymerization reaction temperature is 190℃-205℃, and the reaction time is 2h-12h. For example, the polymerization reaction temperature is 190℃, 195℃, 200℃, 205℃, etc., and the polymerization reaction time is 2h, 3h, 4h, 5h, 6h, 10h, 12h, etc. In the actual preparation process, the degree of polymerization reaction can also be judged by monitoring indicators such as the viscosity or current value of the reaction system.

[0072] In some embodiments, the end-sealing temperature is 120°C-160°C. For example, the end-sealing temperature is 120°C, 130°C, 140°C, 150°C, 160°C, or a range consisting of any two of these values.

[0073] In some implementations, the end-capping process takes 0.5 h to 2 h. Examples include 0.5 h, 1 h, 1.5 h, and 2 h.

[0074] In some embodiments, the first washing includes solid-liquid separation following boiling and / or ultrasonic treatment.

[0075] In some embodiments, the reaction product is further subjected to precipitation followed by solid-liquid separation, crushing, and / or drying before the first washing.

[0076] In some embodiments, the power of the ultrasonic treatment is 20-800W. The power can be 20W, 50W, 60W, 100W, 200W, 300W, 400W, 500W, 600W, 800W, or within any two of the above values.

[0077] In some implementations, the first wash cycle is 1 to 5 times. For example, the first wash cycle may be 1, 2, 3, 4, or 5 times, or fall within any two of these ranges.

[0078] In some embodiments, the cooking temperature is 80-120°C. For example, the cooking temperature is 80°C, 90°C, 100°C, 110°C, 120°C, or a range consisting of any two of these values.

[0079] In some embodiments, the ultrasonic treatment and / or steaming treatment time is 0.5-12 hours. For example, the time is 0.5 hours, 1 hour, 2 hours, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, or within any two of the above values.

[0080] In some embodiments, the first wash includes simultaneous steaming and ultrasonic treatment.

[0081] Thirdly, this application provides an article comprising any of the polyethersulfone compositions described above or a polyethersulfone composition prepared by any of the preparation methods described above.

[0082] In some embodiments, the article is an optical article or a medical device.

[0083] Main raw material sources: Sodium carbonate: D50 is 180μm, purchased from Shandong Haihua Group Co., Ltd., purity 99%.

[0084] Potassium carbonate: D50 is 200μm, purchased from Uni-Trend, purity 99%.

[0085] Bisphenol S: Purchased from Nantong Botao Chemical Co., Ltd., purity 99.9%.

[0086] 4,4'-Dichlorodiphenyl sulfone: purchased from Jiangxi Jinhai New Energy Technology Co., Ltd., purity 99.9%.

[0087] N-Methyl-2-pyrrolidone: Produced by Wanhua Chemical, with a purity of 99.9%.

[0088] Example 1 This embodiment provides a method for preparing a polyethersulfone composition, comprising the following steps: (1) Salt formation reaction: 21165g of N-methylpyrrolidone was added to a 150L reactor. 22522g (90mol) of bisphenol S, 25844g (90mol) of dichlorodiphenyl sulfone, and 10493g (99mol) of sodium carbonate were added to N-methylpyrrolidone in sequence. The mixture was heated to 180℃ and refluxed to remove water. After 3h of reaction, no more water was produced.

[0089] (2) Polymerization reaction and end-capping treatment: The temperature was then raised to 190℃ for 2 hours, and then raised to 200℃ for 2 hours. Then 15000g of N-methylpyrrolidone was added, and the temperature was lowered to 150℃. Chloromethane was continuously introduced at a flow rate of 0.08mol / min for end-capping treatment. The end-capping reaction was completed after 60 minutes of continuous introduction.

[0090] (3) Post-processing stage: The reaction solution obtained in step (2) is slowly poured into water for precipitation. After discarding the water, the precipitate is crushed and dried to obtain polyethersulfone powder.

[0091] (4) Washing stage: Then add 200L of deionized water and 500g of sodium bicarbonate to the polyethersulfone powder, heat to 100℃ and cook while ultrasonic treatment is performed. The ultrasonic power is 200W and the time is 2h. After filtration, collect the washed polyethersulfone powder. Repeat the above washing operation 3 times. Then add 200L of deionized water for washing. After drying, the polyethersulfone composition is obtained.

[0092] Example 2 The process is basically the same as in Example 1, except that in step (1) the salt formation reaction, 99 mol of potassium carbonate is used instead of 99 mol of sodium carbonate. In step (4) the washing stage, 500 g of potassium bicarbonate is used instead of 500 g of sodium bicarbonate.

[0093] Example 3 The process is basically the same as in Example 1, except that in step (1) the salt formation reaction, a mixture of 49.5 mol potassium carbonate and 49.5 mol sodium carbonate is used instead of 99 mol sodium carbonate. In step (4) the washing stage, 500 g potassium bicarbonate is used instead of 500 g sodium bicarbonate.

[0094] Example 4 It is basically the same as Example 2, except that in step (4) washing stage, a mixture of 300g potassium bicarbonate and 300g sodium bicarbonate is used instead of 500g sodium bicarbonate.

[0095] Example 5 The process is basically the same as in Example 1, except that in step (4), the washing stage, boiling is not used. Specifically, 200L of deionized water and 500g of sodium bicarbonate are added to the polyethersulfone powder, and ultrasonic treatment is performed at a power of 200W for 2 hours. After filtration, the washed polyethersulfone powder is collected. The above washing operation is repeated 3 times, and the polyethersulfone composition is obtained after drying.

[0096] Example 6 The process is basically the same as in Example 1, except that ultrasonic-assisted washing is not used in step (4) of the washing stage. Specifically, 200L of deionized water and 500g of sodium bicarbonate are added to the polyethersulfone powder, heated to 100°C for cooking, and the cooking is continued for 2 hours. After filtration, the washed polyethersulfone powder is collected. The above washing operation is repeated 3 times, and the polyethersulfone composition is obtained after drying.

[0097] Example 7 This embodiment provides a method for preparing a polyethersulfone composition, comprising the following steps: (1) Salt formation reaction: 35000g of N-methylpyrrolidone was added to a 150L reactor. 20215g (80mol) of bisphenol S, 23601g (82mol) of dichlorodiphenyl sulfone, and 10493g (99mol) of sodium carbonate were added to N-methylpyrrolidone in sequence. The mixture was heated to 140℃ and refluxed to remove water. After 6h of reaction, no more water was produced.

[0098] (2) Polymerization reaction: The temperature was then raised to 190℃ for 2 hours, and then raised to 200℃ for 2 hours. Then 25000g of N-methylpyrrolidone was added, and the temperature was lowered to 160℃. Chloromethane was continuously introduced at a flow rate of 0.2mol / min for 10 minutes. After the introduction was completed, the end-capping reaction was continued at 160℃ for 20 minutes (the total end-capping reaction time was 30 minutes).

[0099] (3) Pretreatment stage: After the end-capping reaction is completed, the reaction solution is slowly poured into water for precipitation. After filtration, the precipitate is crushed and dried to obtain polyethersulfone powder.

[0100] (4) Washing stage: Then add 200L of deionized water and 500g of sodium bicarbonate to the polyethersulfone powder, heat to 80°C and cook while ultrasonic treatment is performed. The ultrasonic power is 50W and the time is 12h. After filtration, collect the washed polyethersulfone powder. Repeat the above washing operation twice. Then add 200L of deionized water for washing. After drying, the polyethersulfone composition is obtained.

[0101] Example 8 This embodiment provides a method for preparing a polyethersulfone composition, comprising the following steps: (1) Salt formation reaction: 15415g of N-methylpyrrolidone was added to a 150L reactor. 23521g (94mol) of bisphenol S, 27545g (96mol) of dichlorodiphenyl sulfone, and 10493g (99mol) of sodium carbonate were added to N-methylpyrrolidone in sequence. The mixture was heated to 160℃ and refluxed to remove water. After 2 hours of reaction, no more water was produced.

[0102] (2) Polymerization reaction: The temperature was then raised to 205℃ and reacted for 8 hours. Then 20000g of N-methylpyrrolidone solvent was added. After cooling to 120℃, chloromethane was continuously introduced at a flow rate of 0.5mol / min for 18 minutes. After the introduction was completed, the end-capping reaction was continued at 120℃ for 42 minutes (the total end-capping reaction time was 60 minutes).

[0103] (3) Pretreatment stage: After the end-capping reaction is completed, the reaction solution is slowly poured into water for precipitation. After discarding the water, the precipitate is crushed and dried to obtain polyethersulfone powder.

[0104] (4) Washing stage: Then add 200L of deionized water and 500g of sodium bicarbonate to the polyethersulfone powder, heat to 100℃ and cook while ultrasonic treatment is performed. The ultrasonic power is 800W and the time is 0.5h. After filtration, collect the washed polyethersulfone powder. Repeat the above washing operation 5 times. Then add 200L of deionized water for washing. After drying, the polyethersulfone composition is obtained.

[0105] Example 9 It is basically the same as Example 2, except that in step (4) washing stage, the amount of potassium bicarbonate is adjusted to 30g.

[0106] Example 10 It is basically the same as Example 2, except that in step (4) washing stage, the amount of potassium bicarbonate is adjusted to 5000g.

[0107] Comparative Example 1 It is basically the same as Example 1, except that sodium bicarbonate is not added in the washing stage of step (4).

[0108] Comparative Example 2 The process is basically the same as in Example 1, except that in step (4) washing, sodium bicarbonate is not added, boiling is not used, and ultrasonic-assisted washing is not used. Specifically, the polyethersulfone powder is then dispersed in 200L of deionized water, filtered, and the washed polyethersulfone powder is collected. The above washing operation is repeated 3 times, and the polyethersulfone composition is obtained after drying.

[0109] Comparative Example 3 The process is basically the same as in Example 2, except that in step (4), during the washing stage, potassium bicarbonate is not added, boiling is not used, and ultrasonic-assisted washing is not employed. Specifically, the polyethersulfone powder is then dispersed in 200L of deionized water, filtered, and the washed polyethersulfone powder is collected. The above washing operation is repeated three times, and the polyethersulfone composition is obtained after drying.

[0110] Test Example 1 The polyethersulfone compositions prepared in each example and comparative example were subjected to the following tests: (1) The molecular weight of polyethersulfone was determined by permeation gel chromatography (GPC). Before injection, the polyethersulfone composition was dissolved in DMF containing 20 mmol / L lithium bromide to prepare a test solution with a concentration of 0.05 g / mL. The test solution was tested using a GPC instrument with DMF containing 20 mmol / L lithium bromide as the mobile phase and polymethyl methacrylate (PMMA) as the standard sample. The chromatographic column was an Agilent MIXDC, MIXDD, and MIXDE in series, and the flow rate was 1.0 mL / min.

[0111] (2) The total content of N-methyl-4-aminobutyric acid and its alkali metal salt in the polyethersulfone composition was determined by liquid chromatography. Before injection, 3g of the polyethersulfone composition was dissolved in 10mL of DMF, and then 50mL of methanol / DMF (v:v=1:1) was added to the solution as a precipitant. After 0.5h, the solution was filtered and the filtrate was collected to obtain the test solution. The test solution was tested using a Shimadzu LC-20A liquid chromatograph with acetonitrile as mobile phase A and 0.1% acetic acid aqueous solution as mobile phase B (acetic acid was added to improve peak shape). Gradient elution was used (0min, 50% mobile phase A, 15min, 80% mobile phase A). The chromatographic column was SB-Phenyl (4.6*250mm, 5µm), the column temperature was 40℃, and the injection volume was 20µL. The total content of N-methyl-4-aminobutyric acid and its alkali metal salt was quantified by the standard curve method.

[0112] (3) Heat distortion temperature: measured according to ASTM D648 on a 3.2 mm thick molding strip under a load of 1.82 MPa.

[0113] (4) Yellowness index: The polyethersulfone composition was injection molded into a sample with a thickness of 2 mm using an injection molding machine, and the yellowness index of the sample was measured using a Hunter Lab colorimeter.

[0114] Table 1 Test Results

[0115] As can be seen from the results in the table above, compared with Comparative Examples 1-3, the polyethersulfone compositions provided in the embodiments of this application significantly improve the heat distortion temperature and reduce the yellowness index by controlling the content of N-methyl-4-aminobutyric acid and its alkali metal salt.

[0116] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A polyethersulfone composition, characterized in that, include: (a) Polyethersulfone; (b) N-methyl-4-aminobutyric acid and its alkali metal salts; Specifically, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is less than or equal to 50 ppm, and the content of N-methyl-4-aminobutyric acid and its alkali metal salt is not 0.

2. The polyethersulfone composition according to claim 1, characterized in that, The polyethersulfone has a weight-average molecular weight of 50,000-150,000 g / mol; and / or the polyethersulfone has a molecular weight distribution of less than 2.

0.

3. The polyethersulfone composition according to claim 1 or 2, characterized in that, The polyethersulfone composition has a heat distortion temperature of not less than 215°C, measured according to ASTM D648 on a 3.2 mm thick molding strip under a load of 1.82 MPa; and / or, the yellowness index of the polyethersulfone composition is less than 10; and / or, the alkali metal salt of the N-methyl-4-aminobutyric acid includes sodium N-methyl-4-aminobutyrate and / or potassium N-methyl-4-aminobutyrate; and / or, based on the total weight of the polyethersulfone composition, the content of N-methyl-4-aminobutyric acid and its alkali metal salt is 1-15 ppm; and / or, the weight-average molecular weight of the polyethersulfone is 60,000-100,000 g / mol; and / or, the molecular weight distribution of the polyethersulfone is 1.5-1.

9.

4. A method for preparing a polyethersulfone composition according to any one of claims 1-3, characterized in that, Includes the following steps: A monomer containing a bisphenol structure, 4,4'-dichlorodiphenyl sulfone, a salt-forming agent and a reaction solvent are mixed, and the reaction product is obtained through a salt-forming reaction, a polymerization reaction and an end-capping treatment. The reaction product was washed and dried using a weak alkali and water as detergents to obtain a polyethersulfone composition.

5. The method for preparing the polyethersulfone composition according to claim 4, characterized in that, The salt-forming agent is selected from alkali metal carbonates; And / or, the weak base is selected from alkali metal bicarbonates; And / or, the reaction solvent is N-methylpyrrolidone; And / or, the monomer containing the bisphenol structure is bisphenol S; And / or, the end-capping agent used in the end-capping treatment is one or more of chloromethane and 4-chlorophenylsulfone; And / or, the molar ratio of the bisphenol-containing monomer to 4,4'-dichlorodiphenyl sulfone is 1:1.0 to 1:1.03; And / or, the molar ratio of the bisphenol-containing monomer to the salt-forming agent is 1:1.05~1.3; And / or, the mass of the reaction solvent is 20% to 50% of the total mass of the bisphenol-containing monomer, 4,4'-dichlorodiphenyl sulfone, salt-forming agent, and reaction solvent; And / or, the molar ratio of the capping agent to the monomer containing the bisphenol structure is 0.02~0.1:1; And / or, the polymerization reaction and the end-capping treatment may further include a step of diluting the reaction product with a diluting solvent; And / or, the mass ratio of the weak base in the detergent to the monomer containing the bisphenol structure is 30-5000:20000-25000; And / or, the mass ratio of the weak base to the volume of water is 0.15~25g:1L.

6. The method for preparing the polyethersulfone composition according to claim 4, characterized in that, The salt formation process employs a reflux reaction to remove moisture from the reaction system; And / or, the temperature of the salt formation reaction is 140℃-180℃, and the reaction time is 2h-6h; And / or, the polymerization reaction is carried out at a temperature of 190℃-205℃ for a reaction time of 2h-12h; And / or, the end-sealing temperature is 120℃-160℃; And / or, the end-sealing process takes 0.5h-2h.

7. The method for preparing the polyethersulfone composition according to claim 4, characterized in that, The first washing includes solid-liquid separation after boiling and / or ultrasonic treatment. And / or, prior to the first wash, the reaction product may also be subjected to precipitation followed by solid-liquid separation, crushing and / or drying. And / or, the first wash may be performed 1 to 5 times; And / or, the first wash may be followed by a second wash using water as the detergent.

8. The method for preparing the polyethersulfone composition according to claim 7, characterized in that, The power of the ultrasonic treatment is 20-800W; And / or, the cooking temperature is 80-120°C; And / or, the ultrasonic treatment and / or boiling treatment time is 0.5-12 hours; And / or, the first wash includes simultaneous steaming and ultrasonic treatment.

9. An article, characterized in that, This includes the polyethersulfone composition according to any one of claims 1-3 or the polyethersulfone composition prepared by any one of claims 4-8.

10. The article of claim 9, characterized in that, The product is an optical product or a medical device.

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