Sulfone polymer and preparation method thereof

Abstract

The invention relates to a sulfone polymer and a preparation method thereof, and the preparation method comprises the following steps: S1, under the action of reflux, carrying out a salt forming reaction on an organic bisphenol compound and a salt forming agent; s2, 4, 4 '-dichloro diphenyl sulfone is added into a system obtained after the salt forming reaction is completed for a polymerization reaction; wherein the salt forming reaction system in the step S1 comprises the organic bisphenol compound, the salt forming agent, a solvent N-methyl pyrrolidone and 4, 4 '-dichlorodiphenyl sulfone. According to the preparation method of the sulfone polymer in one embodiment of the invention, 4, 4 '-dichlorodiphenyl sulfone is added into a reaction system in batches, so that side reactions caused by the solvent N-methyl pyrrolidone can be reduced, and the sulfone polymer with narrow molecular weight distribution and high thermal stability is prepared.

Description

Technical Field

[0001] The present invention relates to a sulfone polymer, in particular to a sulfone polymer with high thermal stability. Background Art

[0002] Sulfone polymers are an important type of thermoplastic special engineering plastics, mainly including polyethersulfone (PES), bisphenol A polysulfone (PSU), polyphenylene sulfone (PPSU), etc. Sulfone polymer resins have excellent properties, such as excellent mechanical properties, high temperature resistance, chemical corrosion resistance, aging resistance, etc. These characteristics make this type of material widely used in many fields such as electronics and electrical, medical, nuclear power, oil wells, ships, magnetic wires, automobile manufacturing industry and food processing.

[0003] Sulfone polymers are generally prepared by reacting bisphenol compounds, 4,4'-dichlorodiphenyl sulfone, and alkali / alkali metal salts in aprotic solvents. Commonly used aprotic polar solvents include N-methylpyrrolidone (NMP), N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, cyclopentane, etc. Among them, NMP has a high boiling point, strong thermal stability, and is easy to remove during post-treatment, and is often used as a polymerization solvent for sulfone polymers.

[0004] However, in the existing method for preparing the above-mentioned sulfone polymers, the solvent NMP will participate in the reaction, so that the generated polymer contains NMP end groups. The occurrence of this side reaction will not only lead to an imbalance in the ratio of the polymerization monomers and a decrease in the polymerization rate, but also the molecular chain containing the NMP end group has a low thermal stability and is prone to decomposition during the subsequent extrusion granulation and injection molding process, resulting in a decrease in the appearance and performance of the product; at the same time, the generated nitrogen-containing small molecule substances have a pungent odor, which limits the development of the material in high-end applications. Summary of the invention

[0005] In order to overcome at least one defect of the above-mentioned prior art, in a first aspect, an embodiment of the present invention provides a method for preparing a sulfone polymer, comprising the following steps:

[0006] S1: Under the action of reflux, the organic bisphenol compound and the salt-forming agent are subjected to a salt-forming reaction;

[0007] S2: adding 4,4'-dichlorodiphenyl sulfone to the system after the salt-forming reaction is completed to carry out a polymerization reaction;

[0008] The salt-forming reaction system in step S1 includes the organic bisphenol compound, the salt-forming agent, solvent N-methylpyrrolidone and 4,4'-dichlorodiphenyl sulfone.

[0009] In a second aspect, an embodiment of the present invention provides a sulfone polymer prepared by the above-mentioned preparation method.

[0010] The preparation method of sulfone polymers according to one embodiment of the present invention can reduce the occurrence of side reactions caused by solvent N-methylpyrrolidone by adding 4,4'-dichlorodiphenyl sulfone into the reaction system in batches, thereby preparing sulfone polymers with narrow molecular weight distribution and high thermal stability. DETAILED DESCRIPTION

[0011] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions therein are essentially used as illustrations rather than to limit the present invention.

[0012] One embodiment of the present invention provides a method for preparing a sulfone polymer, comprising the following steps:

[0013] S1: Under the action of reflux, the organic bisphenol compound and the salt-forming agent are subjected to a salt-forming reaction;

[0014] S2: adding 4,4'-dichlorodiphenyl sulfone to the system after the salt formation reaction is completed to carry out a polymerization reaction;

[0015] The salt-forming reaction system in step S1 includes an organic bisphenol compound, a salt-forming agent, a solvent N-methylpyrrolidone and 4,4'-dichlorodiphenyl sulfone.

[0016] In one embodiment, the molar ratio of 4,4'-dichlorodiphenyl sulfone contained in the salt-forming reaction system of step S1 to 4,4'-dichlorodiphenyl sulfone added in step S2 can be (5-7):(3-5), and can further be (5-6):(4-5), for example, 5:5, 52:48, 55:45, 58:42, 6:4, 62:38, 65:35, 68:32 or 7:3.

[0017] In one embodiment, step S1 comprises: subjecting the organic bisphenol compound and the salt-forming agent to a salt-forming reaction for 1 to 3 hours (e.g., 1.5 hours, 2 hours, 2.5 hours), then adding 4,4'-dichlorodiphenyl sulfone to the system, and then reacting for another 1 to 3 hours (e.g., 1.5 hours, 2 hours, 2.5 hours).

[0018] In one embodiment, in step S1, a mixture of an organic bisphenol compound, a salt-forming agent, and N-methylpyrrolidone is subjected to a salt-forming reaction for 1 to 3 hours, and then a solution of 4,4'-dichlorodiphenyl sulfone in N-methylpyrrolidone is added to the system, and then the reaction is continued for another 1 to 3 hours; in the mixture, the molar ratio of the organic bisphenol compound to N-methylpyrrolidone is 1:20 to 1:50, and can further be 1:30 to 1:40, for example, 1:25, 1:32, 1:35, 1:38, 1:45.

[0019] In one embodiment, in the N-methylpyrrolidone solution of 4,4'-dichlorodiphenyl sulfone, the molar ratio of 4,4'-dichlorodiphenyl sulfone to N-methylpyrrolidone is 1:5 to 1:10, for example, 1:6, 1:7, 1:8, or 1:9.

[0020] In one embodiment, the molar ratio of the organic bisphenol compound to the salt-forming agent is 1:1 to 1:1.5, and can further be 1:1 to 1:1.3, such as 1:1.1, 1:1.2, or 1:1.4.

[0021] In one embodiment, the molar amount of 4,4'-dichlorodiphenyl sulfone contained in the salt-forming reaction system of step S1 is 50-70% of the molar amount of the organic bisphenol compound, further 50-60%, for example 55%, 58%, 60%, 62%, 65%, 68%.

[0022] In one embodiment, the molar amount of 4,4'-dichlorodiphenyl sulfone added in step S2 is 30-50% of the molar amount of the organic bisphenol compound, further 40-50%, for example 35%, 38%, 40%, 42%, 45%, 48%.

[0023] In one embodiment, the molar number of the organic bisphenol compound used in the preparation method of the sulfone polymer (i.e., the molar number of the organic bisphenol compound added in step S1) is equal to the total molar number of 4,4'-dichlorodiphenyl sulfone used (i.e., the sum of the molar numbers of 4,4'-dichlorodiphenyl sulfone added in steps S1 and S2).

[0024] In one embodiment, the organic bisphenol compound includes one or more of bisphenol A, bisphenol F, dihydroxydiphenyl sulfone, hydroquinone, resorcinol, dihydroxybenzophenone, dihydroxydiphenyl ether, 4,4′-biphenol, hexafluorobisphenol A, tetrabromobisphenol A, and dihydroxynaphthalene.

[0025] In one embodiment, the salt-forming agent includes one or more of potassium salt, sodium salt, sodium hydroxide, and potassium hydroxide; further, the salt-forming agent includes one or more of potassium carbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide.

[0026] In one embodiment, the reaction temperature of step S1 can be 180-200°C, such as 185°C, 190°C, 195°C; the reaction time of step S1 can be 2-10h, further can be 3-5h, such as 4h, 6h, 8h.

[0027] In one embodiment, the reaction temperature of step S2 can be 180-200°C, such as 185°C, 190°C, 195°C; the reaction time of step S2 can be 2-10h, such as 4h, 6h, 8h.

[0028] In one embodiment, a solution of 4,4'-dichlorodiphenyl sulfone in N-methylpyrrolidone (NMP solution) is prepared, and the NMP solution is divided into two parts, the first part of the solution accounts for 50-70% of the total mass of the NMP solution, and the remaining second part of the solution accounts for 30-50% of the total mass of the NMP solution; in step S1, the first part of the solution is added to the salt-forming reaction system, and in step S2, the second part of the solution is added.

[0029] One embodiment of the present invention provides a sulfone polymer, which is prepared by the above-mentioned preparation method.

[0030] In one embodiment, the molecular weight distribution of the sulfone polymer is 1.4 to 1.7, such as 1.5 or 1.6.

[0031] In one embodiment, the weight average molecular weight of the sulfone polymer is 60,000 to 11,000, for example, 65,000, 68,000, 69,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000, 100,000, or 105,000.

[0032] In one embodiment, the content of the polymer of the following structure I in the sulfone polymer is less than 3 mol%;

[0033]

[0034] Wherein, X represents the structure of an organic bisphenol compound; the polymer of structure I is the product of a side reaction in which the solvent N-methylpyrrolidone participates.

[0035] In one embodiment, the content of the polymer of structure I in the sulfone polymer is 0.5-1.1 mol%, such as 0.6 mol%, 0.8 mol%, 1.0 mol%.

[0036] The sulfone polymer prepared in one embodiment of the present invention has the characteristics of high thermal stability and low odor.

[0037] The preparation method of sulfone polymers according to one embodiment of the present invention can reduce the occurrence of side reactions caused by solvent N-methylpyrrolidone by adding 4,4'-dichlorodiphenyl sulfone into the reaction system in batches, thereby preparing sulfone polymers with narrow molecular weight distribution and high thermal stability.

[0038] A method for preparing a sulfone polymer according to an embodiment of the present invention controls the addition method of 4,4'-dichlorodiphenyl sulfone during the salt formation process, thereby reducing the occurrence of side reactions caused by the solvent N-methylpyrrolidone and increasing the reaction rate of the main reaction, so that the prepared sulfone polymer has a narrow molecular weight distribution, high thermal stability, excellent optical properties and less odor after extrusion processing.

[0039] Hereinafter, the preparation method of the sulfone polymer according to one embodiment of the present invention will be further described in conjunction with examples. The test methods involved in each example and comparative example are as follows.

[0040] 1. Weight average molecular weight and molecular weight distribution

[0041] Weight average molecular weight M w The molecular weight distribution was measured by gel permeation chromatography (GPC).

[0042] 2. Structure I content

[0043] The content of structure I was determined by H-NMR spectroscopy ( 1 H-NMR).

[0044] 3. Thermal weight loss temperature

[0045] The 5% thermal weight loss temperature was measured by thermogravimetric analyzer (TGA).

[0046] 4. Odor level

[0047] The odor level is tested according to VW50180 standard requirements.

[0048] Example 1

[0049] S1: Place a four-necked flask with a water separator, a condenser and a mechanical stirrer in an oil bath reactor, add 0.25 mol of bisphenol A, 0.375 mol of potassium carbonate and 12.5 mol of N-methylpyrrolidone into the flask in sequence, raise the reaction temperature to 200°C, and reflux with water at normal pressure for 1 hour; then, add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.175 mol of 4,4'-dichlorodiphenyl sulfone) into the system, maintain the reaction temperature at 200°C, and continue to reflux with water for 1 hour.

[0050] S2: Add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.075 mol of 4,4'-dichlorodiphenyl sulfone) into the system of step S1, maintain the reaction temperature at 200° C., and react at normal pressure for 2 hours to obtain a viscous polymer solution.

[0051] Example 2

[0052] S1: Place a four-necked flask with a water separator, a condenser and a mechanical stirrer in an oil bath reactor, add 0.1 mol of bisphenol A, 0.1 mol of sodium carbonate and 2 mol of N-methylpyrrolidone into the flask in sequence, raise the reaction temperature to 180°C, and reflux with water for 3 hours at normal pressure; then, add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.05 mol of 4,4'-dichlorodiphenyl sulfone) into the system, maintain the reaction temperature at 180°C, and continue to reflux with water for 3 hours.

[0053] S2: Add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.05 mol of 4,4'-dichlorodiphenyl sulfone) into the system of step S1, the reaction temperature is 180° C., and the reaction is carried out at normal pressure for 10 hours to obtain a viscous polymer solution.

[0054] Example 3

[0055] S1: 1 mol of bisphenol A, 1.2 mol of potassium carbonate and 35 mol of N-methylpyrrolidone were put into a reactor equipped with temperature control, stirring and reflux water separation devices at one time, the reaction temperature was raised to 190°C, and refluxed with water for 2 hours at normal pressure; then, 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.6 mol of 4,4'-dichlorodiphenyl sulfone) was put into the system, the reaction temperature was maintained at 190°C, and water was continued for 2 hours.

[0056] S2: Add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 0.4 mol of 4,4'-dichlorodiphenyl sulfone) into the system of step S1, maintain the reaction temperature at 190° C., and react at normal pressure for 6 hours to obtain a viscous polymer solution.

[0057] Example 4

[0058] S1: 4 mol of 4,4'-biphenyldiphenol, 4 mol of sodium carbonate and 80 mol of N-methylpyrrolidone are put into a reactor equipped with temperature control, stirring and reflux water separation devices at one time, the reaction temperature is raised to 180°C, and refluxed with water for 3 hours at normal pressure; then, 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 2 mol of 4,4'-dichlorodiphenyl sulfone) is put into the system, the reaction temperature is maintained at 180°C, and water is continued for 3 hours.

[0059] S2: Add 4,4'-dichlorodiphenyl sulfone / NMP solution (containing 2 mol of 4,4'-dichlorodiphenyl sulfone) into the system of step S1, maintain the reaction temperature at 200° C., and react at normal pressure for 2 hours to obtain a viscous polymer solution.

[0060] Comparative Example 1

[0061] A four-necked flask equipped with a water separator, a condenser and a mechanical stirrer was placed in an oil bath reactor, 0.25 mol of bisphenol A, 0.375 mol of potassium carbonate, 0.25 mol of 4,4'-dichlorodiphenyl sulfone and 12.5 mol of N-methylpyrrolidone were added to the flask in sequence, the reaction temperature was directly raised to 200°C, refluxed with water for 2 hours, and the reaction was continued for 2 hours to obtain a viscous polymer solution.

[0062] Comparative Example 2

[0063] A four-necked flask equipped with a water separator, a condenser and a mechanical stirrer was placed in an oil bath reactor, 0.25 mol of bisphenol A, 0.25 mol of sodium carbonate, 0.25 mol of 4,4'-dichlorodiphenyl sulfone and 5 mol of N-methylpyrrolidone were added to the flask in sequence, the reaction temperature was raised to 180°C, refluxed with water for 6 hours, and the reaction was continued for 10 hours to obtain a viscous polymer solution.

[0064] The sulfone polymers prepared in the examples and comparative examples were tested according to the aforementioned method. The results are shown in Table 1.

[0065] Table 1

[0066]

[0067] It can be seen from the data in Table 1 that in Examples 1 to 4 of the present invention, 4,4'-dichlorodiphenyl sulfone is added to the reaction system twice, and the prepared sulfone polymer has a high molecular weight, a narrow molecular weight distribution, and high thermal stability. Due to the occurrence of side reactions, fewer structures are introduced, and the product performance is greatly improved.

[0068] In Comparative Examples 1 and 2, 4,4'-dichlorodiphenyl sulfone is directly added into the reaction system at one time, and the molecular weight and molecular weight distribution of the obtained sulfone polymers are lower than those of the polymers in Examples 1 to 4; and the content of byproduct structure I in the sulfone polymers in Comparative Examples 1 and 2 is significantly higher than that in Examples 1 to 4, and the thermal weight loss temperature is also lower than that in Examples 1 to 4, and the odor level is also higher. Therefore, the quality of the sulfone polymers obtained in Comparative Examples 1 and 2 is significantly lower than that of the polymers in Examples 1 to 4.

[0069] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0070] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A method for preparing a sulfone polymer, comprising the following steps: S1: Under the action of reflux, the organic bisphenol compound and the salt-forming agent are subjected to a salt-forming reaction; S2: adding 4,4'-dichlorodiphenyl sulfone to the system after the salt-forming reaction is completed to carry out a polymerization reaction; in, The salt-forming reaction system of step S1 includes the organic bisphenol compound, the salt-forming agent, solvent N-methylpyrrolidone and 4,4'-dichlorodiphenyl sulfone.

2. The preparation method according to claim 1, wherein The molar ratio of 4,4'-dichlorodiphenyl sulfone contained in the salt-forming reaction system of step S1 to 4,4'-dichlorodiphenyl sulfone added in step S2 is (5-7):(3-5); and / or, The step S1 comprises: subjecting the organic bisphenol compound and the salt-forming agent to a salt-forming reaction for 1 to 3 hours, then adding 4,4'-dichlorodiphenyl sulfone to the system, and then reacting for another 1 to 3 hours.

3. The preparation method according to claim 1, wherein The step S1 comprises: subjecting the mixture of the organic bisphenol compound, the salt-forming agent and N-methylpyrrolidone to a salt-forming reaction for 1 to 3 hours, then adding a solution of 4,4'-dichlorodiphenyl sulfone in N-methylpyrrolidone to the system, and then reacting for another 1 to 3 hours; Wherein, in the mixture, the molar ratio of the organic bisphenol compound to the N-methylpyrrolidone is 1:20 to 1:50; in the N-methylpyrrolidone solution of 4,4'-dichlorodiphenyl sulfone, the molar ratio of 4,4'-dichlorodiphenyl sulfone to the N-methylpyrrolidone is 1:5 to 1:

10.

4. The preparation method according to claim 1, wherein The reaction temperature of step S1 is 180-200° C.; and / or, The reaction time of step S1 is 2 to 10 hours; and / or, The reaction temperature of step S2 is 180-200° C.; and / or, The reaction time of step S2 is 2 to 10 hours.

5. The preparation method according to claim 1, wherein The organic bisphenol compound includes one or more of bisphenol A, bisphenol F, dihydroxydiphenyl sulfone, hydroquinone, resorcinol, dihydroxybenzophenone, dihydroxydiphenyl ether, 4,4′-biphenol, hexafluorobisphenol A, tetrabromobisphenol A, and dihydroxynaphthalene; and / or, The salt-forming agent includes one or more of potassium salt, sodium salt, sodium hydroxide and potassium hydroxide.

6. The preparation method according to claim 5, wherein: The salt-forming agent includes one or more of potassium carbonate, sodium carbonate, sodium hydroxide and potassium hydroxide.

7. The preparation method according to claim 1, wherein The molar ratio of the organic bisphenol compound to the salt-forming agent is 1:1 to 1:1.5; and / or, The molar number of 4,4'-dichlorodiphenyl sulfone contained in the salt-forming reaction system of step S1 is 50-70% of the molar number of the organic bisphenol compound.

8. The preparation method according to claim 1, wherein The molar ratio of the organic bisphenol compound to the salt-forming agent is 1:1 to 1:1.3; and / or, The molar number of 4,4'-dichlorodiphenyl sulfone added in step S2 is 30-50% of the molar number of the organic bisphenol compound; and / or, In the step S1, the molar ratio of the organic bisphenol compound to the N-methylpyrrolidone is 1:30 to 1:

40.

9. A sulfone polymer obtained by the preparation method according to any one of claims 1 to 8.

10. The sulfone polymer according to claim 9, which has a molecular weight distribution of 1.4 to 1.7.

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