Novel method for efficiently preparing polysulfone resin

Abstract

The invention provides a novel method for efficiently preparing polysulfone resin, and belongs to the field of high polymer materials. According to the synthesis method of the polysulfone resin, the catalyst and the active ligand are mainly added into a reaction system, so that a water removal step is avoided, the reaction time is shortened, the reaction temperature is reduced, and the reaction rate is increased. Comprising the following steps: taking a bisphenol derivative and a dihalogenated benzene compound as reaction monomers, taking sodium carbonate and the like as an acid-binding agent, carrying out reaction in a polar aprotic solvent, carrying out constant-temperature polymerization for 2-3 hours under the protection of nitrogen, and then adding an end-capping reagent to control the progress of the polymerization reaction. And after the reaction is finished, cooling, pressing the material into a filter, filtering, boiling with deionized water for 6-8 times, filtering and drying. According to the technical scheme, the steps of salification and water removal are not needed, the reaction temperature is effectively reduced, the production time is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a novel method for efficiently preparing polysulfone resins. Background Art

[0002] Polysulfone resin is a high-performance engineering plastic. Due to its heat resistance, hot water resistance, creep resistance, dimensional stability, impact resistance, chemical resistance, non-toxicity and flame retardancy, it is widely used in electronics, electrical appliances, machinery, automobiles, medical devices, food processing and non-stick coatings.

[0003] The currently reported industrial preparation and synthesis methods of polysulfone almost entirely adopt the nucleophilic substitution polycondensation route, such as Chinese patents CN105330840A, CN104530431A and CN109354686A, which all disclose the preparation methods of polysulfone resins. There are two production methods: two-step method and one-step method. The two-step synthesis process is to first react bisphenol A with a base such as sodium hydroxide to generate bisphenol A disodium salt, evaporate water through a non-water-soluble solvent such as toluene, and then react with 4,4'-dichlorodiphenyl sulfone in a non-protonic polar solvent for nucleophilic substitution reaction. The one-step synthesis process of polysulfone is to use potassium bicarbonate or potassium carbonate instead of sodium hydroxide to synthesize polysulfone, but because the alkalinity of this type of base is weak, its reaction activity with bisphenol substrate is low. At present, the two-step method is still widely used in industrial synthesis. The method adopts Pd to catalyze the CO coupling reaction. In the reaction mechanism, the Pd catalyst first forms an oxidative addition intermediate with the C-Cl bond, and the intermediate coordinates with the hydroxyl group of bisphenol A, undergoes transmetallation and reduction elimination under the promotion of the base, and finally obtains the target polymer. The method changes the reaction mechanism and the order in which the substrate participates in the reaction. It is not necessary for bisphenol A to react with the base to form a salt first, thereby avoiding the salt formation reaction and water removal operation, and the reaction can be completed in one step. The addition of the catalyst also reduces the activation energy of the reaction, the reaction conditions are milder, and the reaction time is shorter. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing polysulfone resin by a one-step method with high efficiency catalysis under the condition that the molar ratio of reaction monomers is 1:1, without the need for salt formation and water removal operations, thus simplifying the preparation process, accelerating the reaction rate, shortening the reaction time and reducing the reaction cost.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a novel and efficient method for preparing polysulfone resins, comprising the following steps:

[0007] Step 1: Mix the reaction monomer, catalyst, active ligand, acid binding agent and polar solvent, and heat to cause polymerization reaction. The polymerization reaction is completed after 2 hours to obtain a polysulfone solution;

[0008] Step 2: Adding a capping agent to the obtained polysulfone solution for capping. After the capping, the polymer solution is precipitated, washed, and dried to obtain a polysulfone finished resin;

[0009] Wherein, the catalyst in step 1 is a catalyst composed of Pd salt and active ligand.

[0010] Preferably, the catalyst Pd salt is one or more of Pd2(dba)3, Pd(OAc)2, Pd(PPh3)2Cl2, Pd(dppf)Cl2, Pd(MeCN)Cl2, Pd(acac)2, Pd(PPh3)4; the amount used is one ten-thousandth of the molar amount of 4,4'-dichlorodiphenyl sulfone;

[0011] Preferably, the active ligand is DPEphos, BINAP, AdBrettphos, PCy3, Brettphos, PtBu3, Rockphos, Xphos, Trixiephos, Alphos, Amphos, Ad2P n One or more of Bu and Xantphos; the molar ratio of the phosphine ligand to the Pd salt is 1:1 to 2:1, preferably 1.3:1 to 1.5:1.

[0012] Furthermore, the reaction monomers in step 1 are 4,4'-dichlorodiphenyl sulfone and bisphenol derivative monomers; the bisphenol derivative monomers are one or more of 2,2-bis(4-hydroxyphenyl)propane, 4,4'-biphenol, and 4,4'-dihydroxydiphenyl sulfone;

[0013] Preferably, the molar ratio of the 4,4'-dichlorophenyl sulfone to the bisphenol derivative monomer is 1:1.

[0014] Preferably, the acid-binding agent is one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide; the molar ratio of the acid-binding agent to the bisphenol derivative monomer is 1.2:1 to 1.5:1;

[0015] Preferably, the polar solvent is one or more of DMF, DMAC, DMSO, N-methylpyrrolidone, and sulfolane;

[0016] Preferably, the solid content of the reaction monomer in the system obtained after the reaction monomer, catalyst, active ligand, acid-binding agent and polar solvent are mixed is 10% to 20%.

[0017] Preferably, the polymerization reaction temperature is 80° C.-100° C., and the polymerization time is 2 to 3 hours.

[0018] Preferably, the end-capping agent in step 2 is one or more of 4-chlorodiphenyl sulfone, p-methylbenzoyl chloride, chloromethane, chlorobenzene and 4-fluorobenzophenone. When the end-capping agent is two or more of the above-mentioned specific substances, the present invention has no special restrictions on the ratio of the specific substances, and they can be mixed in any ratio;

[0019] Preferably, in step 2, the molar ratio of the end-capping agent to the reactive monomer is 0.5:5 to 1:5; and the end-capping temperature is 80° C. to 100° C.

[0020] The positive effects of the present invention are:

[0021] The present invention provides a novel and efficient method for preparing polysulfone resins. Compared with the reported two-step method and one-step method, the present invention changes the polymerization reaction mechanism and reduces the reaction activation energy by adding a Pd catalyst and an active phosphine ligand. The Pd catalyst first undergoes oxidative addition with the C-Cl bond of 4,4'-dichlorophenylsulfone, and the obtained oxidative addition intermediate is complexed with a bisphenol A compound, and the polymerization reaction is achieved by reduction elimination under the promotion of a base. The path experienced by the present invention no longer relies on nucleophilic substitution, thereby avoiding the operation of first salting and removing water of the nucleophilic reagent bisphenol A with a base. The method of the present invention greatly simplifies the operation process and process, and the presence of the catalyst also accelerates the reaction rate, reduces the reaction temperature, shortens the reaction time, and thus reduces the production cost. The molecular weight of the polysulfone product is easy to control and has an excellent appearance. DETAILED DESCRIPTION

[0022] The present invention provides a novel and efficient method for preparing polysulfone resins, comprising the following steps:

[0023] The reaction monomer, catalyst, active ligand, acid-binding agent and polar solvent are mixed, and a polymerization reaction occurs after heating. After 2 to 3 hours, the obtained polymer system is mixed with a capping agent for capping to obtain a polysulfone resin.

[0024] Wherein, the reaction monomers are 4,4'-dichlorodiphenyl sulfone and bisphenol derivative monomers;

[0025] The bisphenol derivative monomers are 2,2-bis(4-hydroxyphenyl)propane, 4,4'-biphenyldiphenol, and 4,4'-dihydroxydiphenyl sulfone;

[0026] The molar ratio of the 4,4'-dichlorodiphenyl sulfone to the bisphenol derivative monomer is 1:1.

[0027] In the present invention, the reaction process for preparing polysulfone resin is as follows:

[0028]

[0029] In the present invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0030] The present invention mixes the reaction monomer acid-binding agent, the catalyst, the active ligand and the polar solvent to carry out the polymerization reaction in one step;

[0031] In the present invention, the catalyst is one or more of Pd2(dba)3, Pd(OAc)2, Pd(PPh3)2Cl2, Pd(dppf)Cl2, Pd(MeCN)Cl2, Pd(acac)2, Pd(PPh3)4, and the amount used is one ten-thousandth of the molar amount of 4,4'-dichlorodiphenyl sulfone;

[0032] In the present invention, the active ligand is DPEphos, BINAP, AdBrettphos, PCy3, Brettphos, PtBu3, Rockphos, Xphos, Trixiephos, Alphos, Amphos, Ad2P n One or more of Bu and xantphos, the molar ratio of the phosphine ligand to the Pd salt is 1:1 to 2:1, preferably 1.3:1 to 1.5:1;

[0033] In the present invention, the acid binding agent is preferably one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide; when the acid binding agent is two or more of the above-mentioned specific substances, the present invention has no special limitation on the ratio of the specific substances, and they can be mixed in any ratio;

[0034] In the present invention, the molar ratio of the acid binding agent to the reactive monomer is preferably 1.2:1 to 1.5:1;

[0035] In the present invention, the solid content of the system obtained after the reaction monomer, catalyst, active ligand, acid binding agent and polar solvent are mixed is preferably 10% to 20%;

[0036] In the present invention, the mixing is preferably carried out under stirring conditions. The present invention does not have any special limitation on the stirring, and the stirring process well known to those skilled in the art can be used for stirring;

[0037] In the present invention, the polymerization system is heated to generate a polymerization reaction, and after 2 to 3 hours, the obtained polymerization system is mixed with a capping agent to perform end-capping to obtain a polysulfone resin;

[0038] In the present invention, the polymerization reaction temperature is preferably 80°C-100°C;

[0039] In the present invention, the polymerization system obtained by the polymerization reaction is mixed with the end-capping agent at a time point of 2 to 3 hours after the polymerization reaction occurs;

[0040] In the present invention, the end-capping agent is preferably one or more of 4-chlorodiphenyl sulfone, p-methylbenzoyl chloride, chloromethane, chlorobenzene and 4-fluorobenzophenone end-capping agents; when the end-capping agent is two or more of the above-mentioned specific substances, the present invention has no special restrictions on the ratio of the specific substances, and they can be mixed in any ratio;

[0041] In the present invention, the molar ratio of the end-capping agent to the reactive monomer is preferably 0.5:5 to 1:5;

[0042] In the present invention, the end-capping temperature is preferably 80°C to 100°C;

[0043] In the present invention, after the end-capping is completed, the end-capping product system is preferably cooled, washed, filtered and dried to obtain a polysulfone resin. The present invention does not have any special limitation on the cooling, and the cooling process known to those skilled in the art can be used for cooling.

[0044] In the present invention, the washing is preferably performed by boiling with deionized water;

[0045] In the present invention, the number of washing is preferably 6 to 8 times.

[0046] The present invention does not have any special limitation on the filtration, and the filtration process well known to those skilled in the art is adopted;

[0047] In the present invention, the drying is preferably vacuum drying. The present invention has no special limitation on the vacuum drying, and the vacuum drying well known to those skilled in the art can be used for drying.

[0048] In order to further illustrate the present invention, the preparation method of the polysulfone resin provided by the present invention is described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0049] Example 1

[0050] 10.0 kg of cyclopentane was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 50 mg of Pd2(dba)3 as a catalyst, 100 mg of BINAP as an active ligand, and 1.59 kg of sodium carbonate were added in order. The temperature was raised to 100 ° C. and kept constant for 2 hours. The temperature was lowered to 80 ° C. 0.504 kg of 4-chlorodiphenyl sulfone was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6 to 8 times and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =1.04×10 5 , molecular weight distribution index PDI = 2.7, dimer content 1.6%.

[0051] Sample test picture:

[0052] Example 2

[0053] 10.0 kg NMP was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg 4,4'-dichlorodiphenyl sulfone, 2.28 kg 2,2-bis(4-hydroxyphenyl)propane, 60 mg Pd(OAc)2 catalyst, 100 mg PCy3 active ligand, and 1.27 kg sodium carbonate were added in order. The temperature was raised to 100 ° C. and kept constant for 2 hours. The temperature was lowered to 90 ° C. 0.308 kg p-methylbenzoyl chloride was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6 to 8 times and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =1.01×10 5 , molecular weight distribution index PDI = 3.2, dimer content 2.1%.

[0054] Example 3

[0055] 10.0 kg of dimethylacetamide was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under room temperature stirring, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 40 mg of Pd(PPh3)2Cl2 as a catalyst, 100 mg of DPEphos as an active ligand, and 1.66 kg of potassium carbonate were added in order. Stirring was continued, the temperature was raised to 90 ° C, kept constant for 2 hours, cooled to 80 ° C, and 0.224 kg of chlorobenzene was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6-8 times, and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =1.05×10 5 , molecular weight distribution index PDI = 2.5, dimer content 1.5%.

[0056] Example 4

[0057] 10.0 kg of dimethylformamide was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 80 mg of Pd(MeCN)Cl2 catalyst, and 80 mg of Ad2P active ligand were added in sequence. n Bu, 1.66kg potassium carbonate, 1.0L toluene, continue stirring, heat to 100°C, keep constant temperature for 3 hours, cool to 90°C, add 0.11kg methyl chloride, after 30 minutes, the end capping is completed, the end capping product system is cooled, 10.0L volume of water is added, and then filtered, the filter cake is boiled and washed with deionized water for 6-8 times, and vacuum dried to obtain the target product. The molecular weight M is determined by gel permeation chromatography (GPC). w =9.7×10 4 , molecular weight distribution index PDI = 3.5, dimer content 3.1%.

[0058] Example 5

[0059] 10.0 kg of cyclopentane was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 30 mg of Pd(PPh3)2Cl2 as a catalyst, 30 mg of Brettphos as an active ligand, 0.6 kg of sodium hydroxide, and 2.0 L of toluene were added in order. Stirring was continued, the temperature was raised to 100 ° C, kept constant for 2 hours, cooled to 80 ° C, and 0.252 kg of 4-chlorodiphenyl sulfone was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6-8 times, and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =1.07×10 5 , molecular weight distribution index PDI = 2.1, dimer content 1.3%.

[0060] Example 6

[0061] 10.0 kg of cyclopentane was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 80 mg of Pd(acac)2 as a catalyst, 80 mg of PtBu3 as an active ligand, and 1.59 kg of sodium carbonate were added in order. The temperature was raised to 100 ° C. The temperature was kept constant for 3 hours. 0.4 kg of 4-fluorobenzophenone was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6-8 times and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =9.2×10 5 , molecular weight distribution index PDI = 4.1, dimer content 3.1%.

[0062] Example 7

[0063] 10.0 kg of cyclopentane was added to a 30 L stainless steel reactor equipped with a nitrogen tube and a high-efficiency stirrer. Under stirring at room temperature, 2.87 kg of 4,4'-dichlorodiphenyl sulfone, 2.28 kg of 2,2-bis(4-hydroxyphenyl)propane, 80 mg of Pd(PPh3)4 as a catalyst, 30 mg of Amphos as an active ligand, 0.84 kg of potassium hydroxide, and 1.5 L of toluene were added in order. Stirring was continued, and the temperature was raised to 100 ° C. The temperature was kept constant for 2 hours, and 0.252 kg of 4-chlorodiphenyl sulfone was added. After 30 minutes, the end-capping was completed. The end-capped product system was cooled, 10.0 L of water was added, and then filtered. The filter cake was washed with deionized water by boiling for 6-8 times, and vacuum dried to obtain the target product. The molecular weight M was determined by gel permeation chromatography (GPC). w =1.02×10 5 , molecular weight distribution index PDI = 2.9, dimer content 2.1%.

[0064] Finally, it should be noted that the above embodiments are only used to describe the preferred implementation methods of the present invention, rather than to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, a person skilled in the art should understand that various modifications and improvements made by modifying or equivalently replacing the technical solution of the present invention should fall within the protection scope of the claims of the present invention.

Claims

1. A novel and efficient method for preparing polysulfone resins, comprising the following steps: Step 1: Mix the reaction monomer, acid binding agent, catalyst, active ligand and polar solvent, and heat to cause polymerization reaction. The polymerization reaction is completed after 2 hours to obtain a polysulfone solution; Step 2: Adding a capping agent to the obtained polysulfone solution for capping. After the capping, the polymer solution is precipitated, washed, and dried to obtain a polysulfone finished resin; in, The catalyst in step 1 is a catalyst composed of a Pd salt and an active ligand.

2. The preparation method according to claim 1, characterized in that The catalyst Pd salt is one or more of Pd2(dba)3, Pd(OAc)2, Pd(PPh3)2Cl2, Pd(dppf)Cl2, Pd(MeCN)Cl2, Pd(acac)2, Pd(PPh3)4; and the dosage is one ten-thousandth of the molar amount of 4,4'-dichlorodiphenyl sulfone.

3. The preparation method according to claim 1, characterized in that: The active ligand is DPEphos, BINAP, AdBrettphos, PCy3, Brettphos, PtBu3, Rockphos, Xphos, Trixiephos, Alphos, Amphos, Ad2P n One or more of Bu and Xantphos; the molar ratio of the phosphine ligand to the Pd salt is 1:1 to 2:1, preferably 1.3:1 to 1.5:

1.

4. The preparation method according to claim 1, characterized in that: The reaction monomers are 4,4'-dichlorodiphenyl sulfone and bisphenol derivative monomers; the bisphenol derivative monomers are one or more of 2,2-bis(4-hydroxyphenyl)propane, 4,4'-biphenol, and 4,4'-dihydroxydiphenyl sulfone; the molar ratio of the 4,4'-dichlorodiphenyl sulfone to the bisphenol derivative monomer is 1:

1.

5. The preparation method according to claim 1, characterized in that: The acid-binding agent is one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide; the molar ratio of the acid-binding agent to the bisphenol derivative monomer is 1.2:1-1.5:

1.

6. The preparation method according to claim 1, characterized in that: The polar solvent is one or more of DMF, DMAC, DMSO, N-methylpyrrolidone and sulfolane.

7. The preparation method according to claim 1, characterized in that: The solid content of the reaction monomer in the system obtained after the reaction monomer, catalyst, ligand, acid binding agent and polar solvent are mixed is 10% to 20%.

8. The preparation method according to claim 1, characterized in that: The polymerization reaction temperature in step 1 is 80° C. to 100° C., and the polymerization time is 2 to 3 hours.

9. The preparation method according to claim 1, characterized in that: The end-capping agent is one or more of 4-chlorodiphenyl sulfone, p-methylbenzoyl chloride, methyl chloride, chlorobenzene and 4-fluorobenzophenone.

10. The preparation method according to claim 1, characterized in that: In step 2, the molar ratio of the end-capping agent to the reaction monomer is 0.5:5 to 1:5; and the end-capping temperature is 80° C. to 100° C.

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