CN109721733B - Preparation method of polysulfone resin - Google Patents

Abstract

The invention provides a preparation method of polysulfone resin, which comprises the following steps: a) carrying out a polymerization reaction of bisphenol monomer, salt-forming agent, composite base catalyst and dihalogen monomer in a solvent to obtain a polymer solution; Described composite base catalyst contains structure shown in formula (I) or formula (II); Wherein, -R ₁ is selected from -CH ₃ or phenyl; -R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or isopropyl base; -R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ; b) the polymer solution obtained in step a) is solidified in water and then pulverized, then washed with water, vacuum dried and granulated to obtain a polysulfone resin. Compared with the prior art, the preparation method provided by the present invention adopts a specific composite base catalyst, so that the polymerization reaction is carried out under a phase transfer catalytic system, thereby reducing (or partially inhibiting) the generation of cyclic oligomers during the reaction process. , in order to reduce its content in the polymer solution, so that the obtained polymer solution can obtain polysulfone resin with lower cyclic oligomer content without additional organic solvent purification.

Description

A kind of preparation method of polysulfone resin

technical field

The invention relates to the technical field of polymer synthesis, and more particularly, to a preparation method of a polysulfone resin.

Background technique

Polysulfone resin (PSF) is a thermoplastic special engineering plastic, the main types include: polyphenylsulfone (PPSU), polyethersulfone (PES) and polysulfone (PSU). Polysulfone resins have the advantages of high strength, good toughness, high temperature resistance, chemical corrosion resistance, and excellent film-forming properties. They can be processed into flat membranes, hollow fibers, ultrafiltration membranes and other devices, and are widely used in electronics, Industrial areas such as automobiles and aircraft, as well as water treatment processes. Not only that, polysulfone resins also have the advantages of non-toxicity, radiation resistance and hydrolysis resistance, especially under high temperature continuous load conditions or in steam and sterilization environments, they can still maintain good mechanical properties and low creep properties. The long-term use temperature has reached more than 160 ℃, and it has been widely used in food hygiene, medical equipment and so on.

Taking polysulfone as an example, its global usage shows an annual growth rate of more than 10% (the global annual output of polysulfone resin exceeds 40,000 tons), while the average annual growth rate of China's demand for polysulfone exceeds 20%. As of 2017, the annual domestic demand for polysulfone has exceeded 6,000 tons, especially in the field of medical applications, which is increasing year by year. However, the current domestic production capacity of polysulfone is about 1500-2000 tons/year. Compared with similar foreign polysulfone products, domestic polysulfone not only has many problems such as backward production process, poor batch stability, high content of impurities such as oligomers and metal ions, but also unable to compete with imported products in terms of variety or price; especially Almost all of the medical-grade polysulfone materials used in the preparation of high-end medical products such as hemodialysis membranes, membrane oxygenators, and artificial heart valves are imported. In addition, due to the high content of impurities such as cyclic oligomers and metal ions, domestic polysulfone resins are prone to problems such as low light transmittance, uneven color and low processing yield when using them to prepare thin-film devices. It limits its wide application in the field of high-end optical films. In summary, the purity of polysulfone resins, especially the high impurity content of cyclic oligomers, is the main bottleneck restricting the wide application of polysulfone resins in high-end medical fields and high-end optical fields.

Polysulfone resins are usually composed of bisphenol monomers (bisphenol A, bisphenol S, biphenol, etc.) and 4,4'-dichlorodiphenylsulfone in alkaline (NaOH, KOH, K ₂ CO ₃ , It is prepared by polycondensation reaction under the conditions of K ₃ PO ₄ , etc.), and there are two common synthesis methods - Farnham (Farnham) nucleophilic substitution reaction and one-step synthesis method. Although there are differences between these two preparation techniques and processes, they both aim to prepare phenolic metal salts (NaOAr or KOAr) and complete sufficient polymerization under appropriate temperature conditions. Taking the synthesis of polysulfone as an example: the two-step synthesis method is usually to react bisphenol A with sodium hydroxide (or potassium hydroxide) in dimethyl sulfoxide (DMSO) solvent to generate the sodium salt (or potassium salt) of bisphenol A. , and then distill off the water separation agent (toluene, xylene, cyclohexane, etc.); after the water separation is completed, add 4,4'-dichlorodiphenylsulfone to it to carry out the polycondensation reaction at 140-160 °C. This polycondensation process is described in detail in US patent US1978/US4108837. However, the production process is relatively complicated, especially the high requirements for the control of the water content of the system, and the strict control of conditions during the secondary feeding. The one-step synthesis method usually uses inorganic medium and strong bases (potassium carbonate, sodium carbonate, cesium carbonate, etc.) as salt-forming reagents; this method can realize one-step feeding, which greatly simplifies the production process. However, the bicarbonate generated during the salt formation reaction will generate water when heated, which makes the azeotropic water separation step necessary. In recent years, Chinese patent CN200910069382.2 discloses a new method for preparing polysulfone resin by a water-free process. Since the reaction process can produce stable potassium phosphate hydrate, the step of azeotropic water separation is omitted, and the Reaction time; Chinese patent CN201110286532.2 discloses a method for preparing polysulfone in composite ionic liquid solvent, which shortens salt formation time and dehydration time, and realizes green recovery of solvent; Chinese patent CN201410790045.3 and CN201510361661.1 The invention discloses a high-pressure (2.0-3.0MPa) synthesis process and a method for preparing polysulfone resin by using microwave as a heat source, which greatly shortens the polymerization reaction time and saves energy consumption.

After half a century of development, most of the developed polysulfone resin production technologies focus on the adjustment of alkali species, the optimization of the reaction solvent system, and the simplification of the dehydration process. However, there is no effective control over the content of cyclic oligomers in the polymerization reaction system. Cyclic oligomer is also called cyclic oligomer, and its chemical structure (taking polysulfone as an example) is shown in formula (III);

Among them, n=1-5. In the polycondensation reaction of polysulfone resins, the resulting polymers are mainly linear polymers and there are also a small amount of cyclic oligomers, among which the cyclic oligomers are cyclic dimers, trimers and tetramers. thing-based. Different polymerized monomer structures and different polymerization processes eventually lead to large differences in the content of cyclic oligomers in polysulfone resins. Due to the great difference between the solubility and rigidity of these cyclic oligomers and the linear polymer main chain, and the excessively high content of cyclic oligomers are important reasons for the opacity (or turbidity of the solution) of polysulfone resins. For the above reasons, it is necessary to control the content of cyclic oligomers in high-purity polysulfone-based resins. US Patent US2001/0056175A1 discloses a method for reducing cyclic oligomers in polysulfone resins by using chlorobenzene as a solvent and methanol as a precipitation solvent, but the post-processing process needs to use a large amount of organic solvents, and faces the The problem of difficult recovery of organic solvents in the ternary azeotrope system; Chinese patent CN201210380356.3 discloses a method for preparing polysulfone resin by flash precipitation, which effectively reduces the content of inorganic salt particles wrapped by polysulfone resin, thereby increasing the Product purity, and overcome the problem of high energy consumption for solvent recovery after precipitation; Chinese patent CN201710625749.9 discloses a polymer solution obtained by centrifuging and filtering the diluted polymer solution to obtain a polymer solution of high-purity polysulfone, and then concentrated , Extrusion granulation to obtain high-purity polysulfone resin.

However, most of these methods for preparing high-purity polysulfone resins are to first prepare the corresponding polysulfone resins, and then separate and purify them to achieve the purpose of reducing the content of cyclic oligomers; the purification process requires a large amount of organic solvents (such as methanol, ethanol, isopropanol, toluene, xylene, chlorobenzene, etc.), or the same solvent as the polymerization system as a diluent (such as DMSO, DMAc, NMP, sulfolane, etc.).

SUMMARY OF THE INVENTION

In view of this, the object of the present invention is to provide a preparation method of polysulfone resin, which can reduce (or partially inhibit) the generation of cyclic oligomers in the reaction process, so as to reduce its content in the polymer solution, Thus, the obtained polymer solution can obtain polysulfone resin with lower cyclic oligomer content without additional organic solvent purification.

The invention provides a preparation method of polysulfone resin, comprising the following steps:

a) polymerizing bisphenol monomer, salt-forming agent, composite base catalyst and dihalogen monomer in a solvent to obtain a polymer solution; the composite base catalyst contains the structure represented by formula (I) or formula (II) ;

-R₂选自-CH₃、-CH₂CH₃或

-R₃选自-CH₃、-CH₂CH₃；Wherein, -R ₁ is selected from -CH ₃ or

-R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or

-R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ;

b) The polymer solution obtained in step a) is solidified in water and then pulverized, and then washed with water, vacuum dried and granulated in sequence to obtain a polysulfone resin.

Preferably, the bisphenol monomer in step a) is selected from bisphenol A, bisphenol S or 4,4'-biphenol.

Preferably, the salt-forming agent in step a) is selected from one or more of NaOH, KOH, K ₂ CO ₃ and K ₃ PO ₄ .

Preferably, the amount of the composite base catalyst in step a) is 0.1% to 3% of the molar amount of the bisphenol monomer.

Preferably, the dihalogen monomer in step a) is selected from 4,4'-dichlorodiphenylsulfone, 4,4'-tetrafluorodiphenylsulfone or 4,4'-difluorobenzophenone.

Preferably, the molar ratio of the bisphenol monomer, the salt-forming agent and the dihalogen monomer in step a) is 1:(2-3):(0.8-1.2).

Preferably, the temperature of the polymerization reaction in step a) is 70°C to 220°C, and the time is 1 h to 15 h.

Preferably, the process of the polymerization reaction described in step a) is specifically:

Dissolving the bisphenol monomer in a solvent, adding a salt-forming agent and a composite alkali catalyst to carry out a water separation reaction, then adding a dihalogen monomer to heat up, and performing a first polycondensation reaction to obtain a polymer solution;

Or adding bisphenol monomer, dihalogen monomer, salt-forming agent and composite base catalyst to the solvent to carry out water separation reaction, heating up, and carrying out the second polycondensation reaction to obtain a polymer solution;

Or after adding the bisphenol monomer, the dihalogen monomer, the salt-forming agent and the composite alkali catalyst in sequence to the solvent, the temperature is raised, the third polycondensation reaction is carried out, and the polymer solution is obtained after dilution.

Preferably, the temperature of the water separation reaction is 110°C to 150°C, and the time is 5h to 7h.

Preferably, the temperature of the vacuum drying in step b) is 100°C to 150°C, and the time is 20h to 30h.

The invention provides a preparation method of polysulfone resin, which comprises the following steps: a) carrying out a polymerization reaction of bisphenol monomer, salt-forming agent, composite base catalyst and dihalogen monomer in a solvent to obtain a polymer solution; The composite base catalyst contains the structure represented by formula (I) or formula (II); wherein, -R ₁ is selected from -CH ₃ or phenyl; -R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or isopropyl base; -R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ; b) the polymer solution obtained in step a) is solidified in water, pulverized, washed with water, vacuum dried and granulated to obtain polysulfone resin. Compared with the prior art, the preparation method provided by the present invention adopts a specific composite base catalyst, so that the polymerization reaction is carried out under a phase transfer catalytic system, thereby reducing (or partially inhibiting) the generation of cyclic oligomers during the reaction process. , in order to reduce its content in the polymer solution, so that the obtained polymer solution can obtain polysulfone resin with lower cyclic oligomer content without additional organic solvent purification; The method avoids the complicated organic solvent purification process and simplifies the preparation process. The experimental results show that the bicyclic oligomer content of the polysulfone resin prepared by the preparation method provided by the present invention can be reduced to 1.06%, and the total cyclic oligomer content can be reduced to 3.51%.

In addition, the preparation method provided by the present invention has wide adaptability, and can prepare different types of polysulfone resins such as PPSU, PES and PSU by combining one-step synthesis, two-step synthesis and no water separation.

Description of drawings

Fig. 1 is the proton nuclear magnetic resonance spectrogram of the PTC1 composite base catalyst used in the embodiment of the present invention;

Fig. 2 is the carbon nuclear magnetic resonance spectrogram of the PTC1 composite base catalyst used in the embodiment of the present invention;

Fig. 3 is the proton nuclear magnetic resonance spectrogram of the PTC2 composite base catalyst used in the embodiment of the present invention;

Fig. 4 is the carbon nuclear magnetic resonance spectrogram of the PTC2 composite base catalyst used in the embodiment of the present invention;

Fig. 5 is the hydrogen nuclear magnetic resonance spectrogram of the PTC3 composite base catalyst used in the embodiment of the present invention;

Fig. 6 is the carbon nuclear magnetic resonance spectrogram of the PTC3 composite base catalyst used in the embodiment of the present invention;

Fig. 7 is the hydrogen nuclear magnetic resonance spectrogram of the PTC4 composite base catalyst used in the embodiment of the present invention;

Fig. 8 is the carbon nuclear magnetic resonance spectrogram of the PTC4 composite base catalyst used in the embodiment of the present invention;

Fig. 9 is the hydrogen nuclear magnetic resonance spectrogram of the PTC5 composite base catalyst used in the embodiment of the present invention;

Fig. 10 is the carbon nuclear magnetic resonance spectrogram of the PTC5 composite base catalyst used in the embodiment of the present invention;

Fig. 11 is the hydrogen nuclear magnetic resonance spectrogram of the PTC6 composite base catalyst used in the embodiment of the present invention;

Fig. 12 is the carbon nuclear magnetic resonance spectrogram of the PTC6 composite base catalyst used in the embodiment of the present invention;

Figure 13 is the infrared spectrogram of the polysulfone prepared by the preparation method provided in Example 5 of the present invention;

Fig. 14 is the hydrogen nuclear magnetic resonance spectrum of polysulfone prepared by the preparation method provided in Example 5 of the present invention;

Figure 15 is a gel chromatogram of polysulfone prepared by the preparation method provided in Example 5 of the present invention;

16 is a gel chromatogram of polysulfone prepared by the preparation method provided in Comparative Example 1.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention provides a preparation method of polysulfone resin, comprising the following steps:

a) polymerizing bisphenol monomer, salt-forming agent, composite base catalyst and dihalogen monomer in a solvent to obtain a polymer solution; the composite base catalyst contains the structure represented by formula (I) or formula (II) ;

-R₂选自-CH₃、-CH₂CH₃或

-R₃选自-CH₃、-CH₂CH₃；Wherein, -R ₁ is selected from -CH ₃ or

-R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or

-R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ;

b) The polymer solution obtained in step a) is solidified in water and then pulverized, and then washed with water, vacuum dried and granulated in sequence to obtain a polysulfone resin.

In the present invention, the bisphenol monomer, the salt-forming agent, the composite base catalyst and the dihalogen monomer are firstly polymerized in a solvent to obtain a polymer solution. In the present invention, the bisphenol monomer is preferably selected from bisphenol A, bisphenol S or 4,4'-biphenol; wherein, bisphenol A is used to prepare PSU, bisphenol S is used to prepare PES, 4,4'-Biphenol was used to prepare PPSU. In a preferred embodiment of the present invention, the bisphenol monomer is bisphenol A. The source of the bisphenol monomer is not particularly limited in the present invention, and the commercial products or laboratory products of the above-mentioned bisphenol A, bisphenol S and 4,4'-biphenol that are well known to those skilled in the art are used. Can.

In the present invention, the salt-forming agent is preferably selected from one or more of NaOH, KOH, K ₂ CO ₃ and K ₃ PO ₄ , more preferably KOH. In a preferred embodiment of the present invention, the KOH is added in the form of an aqueous solution, which is not particularly limited in the present invention. The source of the salt-forming agent is not particularly limited in the present invention, and commercially available products of the above-mentioned NaOH, KOH, K ₂ CO ₃ and K ₃ PO ₄ well known to those skilled in the art can be used.

In the present invention, the molar ratio of the salt-forming agent to the bisphenol monomer is preferably (2-3):1, more preferably (2-2.4):1.

In the present invention, the composite base catalyst contains a structure represented by formula (I) or formula (II), preferably a structure represented by formula (II);

优选为

-R₂选自-CH₃、-CH₂CH₃或

优选为

-R₃选自-CH₃、-CH₂CH₃，优选为-CH₂CH₃。Wherein, -R ₁ is selected from -CH ₃ or

preferably

-R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or

preferably

-R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ , preferably -CH ₂ CH ₃ .

(依次记为PTC1～6复合碱催化剂)中的一种或多种，更优选为

更更优选为

本发明对所述复合碱催化剂的来源没有特殊限制，采用本领域技术人员熟知的制备方法即可。In the present invention, the composite base catalyst is preferably selected from

One or more of (referred to as PTC1-6 composite base catalysts in turn), more preferably

More preferably

The present invention has no particular limitation on the source of the composite base catalyst, and a preparation method well known to those skilled in the art can be used.

In the present invention, the dosage of the composite base catalyst is preferably 0.1% to 3% of the molar amount of the bisphenol monomer, and more preferably 0.2% to 0.5% of the molar amount of the bisphenol monomer.

In the present invention, the dihalogen monomer is preferably selected from 4,4'-dichlorodiphenylsulfone, 4,4'-tetrafluorodiphenylsulfone or 4,4'-difluorobenzophenone, more preferably For 4,4'-dichlorodiphenylsulfone. The source of the dihalogen monomer is not particularly limited in the present invention, and the above-mentioned 4,4'-dichlorodiphenyl sulfone, 4,4'-tetrafluorodiphenyl sulfone and 4,4'- Commercially available or laboratory-made difluorobenzophenones are available.

In the present invention, the molar ratio of the dihalogen monomer to the bisphenol monomer is preferably (0.8-1.2):1, more preferably 1:1.

In the present invention, the solvent is preferably selected from one or more of DMAc, DMSO, NMP and sulfolane, more preferably DMAc or DMSO. In the present invention, there is no special limitation on the source of the solvent, and commercially available products of the above polar aprotic solvent well known to those skilled in the art can be used. In the present invention, the dosage ratio of the solvent to the bisphenol monomer is preferably (1.5L-5L):1kg, more preferably (4L-5L):1kg.

In the present invention, the temperature of the polymerization reaction is preferably 70°C to 220°C, more preferably 80°C to 160°C; the time of the polymerization reaction is preferably 1h to 15h, more preferably 3h to 12h.

In the present invention, the process of described polymerization reaction is preferably specifically:

Dissolving the bisphenol monomer in a solvent, adding a salt-forming agent and a composite alkali catalyst to carry out a water separation reaction, then adding a dihalogen monomer to heat up, and performing a first polycondensation reaction to obtain a polymer solution;

Or adding bisphenol monomer, dihalogen monomer, salt-forming agent and composite base catalyst to the solvent to carry out water separation reaction, heating up, and carrying out the second polycondensation reaction to obtain a polymer solution;

Or after adding bisphenol monomer, dihalogen monomer, salt-forming agent and composite base catalyst in sequence in the solvent, heating up, carrying out the third polycondensation reaction, and diluting to obtain a polymer solution;

More preferably:

The bisphenol monomer is dissolved in the solvent, the salt-forming agent and the composite alkali catalyst are added to carry out the water separation reaction, and then the dihalogen monomer is added to heat up, and the first polycondensation reaction is carried out to obtain a polymer solution.

In the present invention, the process of the polymerization reaction is preferably carried out under nitrogen protection and stirring conditions.

In a preferred embodiment of the present invention, the process of the polymerization reaction is specifically:

The bisphenol monomer is dissolved in the solvent, the salt-forming agent and the composite alkali catalyst are added to carry out the water separation reaction, and then the dihalogen monomer is added to heat up, and the first polycondensation reaction is carried out to obtain a polymer solution. In the present invention, the bisphenol monomer is first dissolved in a solvent; the bisphenol monomer and the solvent are the same as those described in the above technical solutions, and are not repeated here.

In the present invention, the temperature of the dissolution is preferably 70°C to 90°C, and more preferably 80°C.

After the bisphenol monomer is completely dissolved, the present invention adds a salt-forming agent and a composite base catalyst to carry out a water separation reaction; the salt-forming agent and the composite base catalyst are the same as those described in the above technical solutions, and will not be repeated here. .

In the present invention, the temperature of the water separation reaction is preferably 110°C to 150°C, more preferably 140°C; the time of the water separation reaction is preferably 5h to 7h, more preferably 6h.

After the water separation is completed, the present invention then adds the dihalogen monomer to heat up, and performs the first polycondensation reaction to obtain a polymer solution; the dihalogen monomer is the same as that described in the above technical solution, and will not be repeated here.

In the present invention, the temperature of the first polycondensation reaction is preferably 160°C to 220°C, more preferably 160°C; the time of the first polycondensation reaction is preferably 1h to 6h, more preferably 1h to 3h.

In another preferred embodiment of the present invention, the process of the polymerization reaction is specifically:

The bisphenol monomer, the dihalogen monomer, the salt-forming agent and the composite base catalyst are sequentially added to the solvent to carry out the water separation reaction, and then the temperature is raised to carry out the second polycondensation reaction to obtain a polymer solution. In the present invention, the solvent, the bisphenol monomer, the dihalogenated monomer, the salt-forming agent and the composite base catalyst are the same as those described in the above technical solutions, and will not be repeated here.

In the present invention, the temperature of the water separation reaction is preferably 110°C to 150°C, more preferably 140°C; the time of the water separation reaction is preferably 5h to 7h, more preferably 6h.

In the present invention, the temperature of the second polycondensation reaction is preferably 160°C to 220°C, more preferably 160°C; the time of the second polycondensation reaction is preferably 1h to 6h, more preferably 3h to 6h.

In another preferred embodiment of the present invention, the process of the polymerization reaction is specifically:

After adding the bisphenol monomer, the dihalogen monomer, the salt-forming agent and the composite alkali catalyst in sequence to the solvent, the temperature is raised to carry out the third polycondensation reaction, and the polymer solution is obtained after dilution. In the present invention, the solvent, the bisphenol monomer, the dihalogenated monomer, the salt-forming agent and the composite base catalyst are the same as those described in the above technical solutions, and will not be repeated here.

In the present invention, the temperature of the third polycondensation reaction is preferably 160°C to 220°C, more preferably 160°C; the time of the third polycondensation reaction is preferably 1h to 6h, more preferably 3h to 6h.

The present invention does not have a special limitation on the dilution process, and the dilution can be performed with the same solvent as that used in the polymerization reaction.

In the present invention, the viscosity of the polymer solution is preferably 0.40 to 0.80 dL g ^-1 , more preferably 0.50 dLg ^-1 .

The preparation method provided by the present invention adopts a specific composite base catalyst, so that the polymerization reaction is carried out under a phase transfer catalytic system, so as to reduce (or partially inhibit) the generation of cyclic oligomers during the reaction process, so as to reduce its concentration in the polymer. content in the solution.

After the polymer solution is obtained, in the present invention, the obtained polymer solution is solidified in water and then pulverized, and then washed with water, vacuum dried and granulated in sequence to obtain a polysulfone resin. In the present invention, it is preferable to further comprise:

The polymer solution is cooled; the cooling temperature is preferably 20°C to 30°C, more preferably 25°C.

The present invention has no special restrictions on the process of solidification and pulverization in the water, and the technical solutions well known to those skilled in the art can be used. In the present invention, the purpose of the water washing is to remove salt, which is not particularly limited in the present invention.

In the present invention, the temperature of the vacuum drying is preferably 100°C to 150°C, more preferably 120°C; the time of the vacuum drying is preferably 20h to 30h, more preferably 24h.

The present invention has no special limitation on the granulation process, and the technical solutions well known to those skilled in the art can be used.

The polymer solution obtained by the present invention can obtain polysulfone resin with lower cyclic oligomer content without additional organic solvent purification; meanwhile, the preparation method provided by the present invention avoids the complicated organic solvent purification process and simplifies the preparation craft.

The present invention provides a method for preparing polysulfone resin, which comprises the following steps: a) conducting a polycondensation reaction with a bisphenol monomer, a salt-forming agent, a composite base catalyst and a dihalogen monomer in a solvent to obtain a polymer solution; The composite base catalyst contains the structure represented by formula (I) or formula (II); wherein, -R ₁ is selected from -CH ₃ or phenyl; -R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or isopropyl base; -R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ; b) the polymer solution obtained in step a) is solidified in water, pulverized, washed with water, vacuum dried and granulated to obtain polysulfone resin. Compared with the prior art, the preparation method provided by the present invention adopts a specific composite base catalyst, so that the polymerization reaction is carried out under a phase transfer catalytic system, thereby reducing (or partially inhibiting) the generation of cyclic oligomers during the reaction process. , in order to reduce its content in the polymer solution, so that the obtained polymer solution can obtain polysulfone resin with lower cyclic oligomer content without additional organic solvent purification; The method avoids the complicated organic solvent purification process and simplifies the preparation process. The experimental results show that the bicyclic oligomer content of the polysulfone resin prepared by the preparation method provided by the present invention can be reduced to 1.06%, and the total cyclic oligomer content can be reduced to 3.51%.

In addition, the preparation method provided by the present invention has wide adaptability, and can prepare different types of polysulfone resins such as PPSU, PES and PSU by combining one-step synthesis, two-step synthesis and no water separation.

In order to further illustrate the present invention, the following examples are used for detailed description. The structural formula of the PTC1 composite base catalyst used in the following examples of the present invention is shown in formula (I-1);

Its preparation method is as follows:

Under ice bath, 1,8-diazabicycloundec-7-ene (DBU) was added with bromoethane, and the reaction was stirred at room temperature for 5 h, and then filtered; washed several times with ethyl acetate and diethyl ether, respectively , obtain a white solid, and then obtain the corresponding hydroxide form through a basic ion exchange resin, and the yield is greater than 95%; it is confirmed by the hydrogen NMR spectrum and carbon spectrum that it is the target product PTC1 composite base catalyst. The carbon spectrum is shown in Figures 1-2.

The structural formula of the PTC2 composite base catalyst used in the following examples of the present invention is shown in formula (I-2);

Its preparation method is as follows:

Under ice bath, benzyl bromide was added to 1,8-diazabicycloundec-7-ene (DBU), the reaction was stirred at room temperature for 5 h, and then filtered; washed with ethyl acetate and ether for several times respectively , obtain a white solid, and then obtain the corresponding hydroxide form through a basic ion exchange resin, and the yield is greater than 95%; it is confirmed by the hydrogen NMR spectrum and carbon spectrum that it is the target product PTC2 composite base catalyst. The carbon spectrum is shown in Figures 3-4.

The reaction formula of the PTC1 composite base catalyst and the PTC2 composite base catalyst is shown in formula (IV);

The structural formula of the PTC3 composite base catalyst used in the following examples of the present invention is shown in formula (II-1);

The structural formula of the used PTC4 composite base catalyst is shown in formula (II-2);

The structural formula of the used PTC5 composite base catalyst is shown in formula (II-3);

The structural formula of the used PTC6 composite base catalyst is shown in formula (II-4);

For the preparation methods of the above-mentioned PTC3-6 composite base catalysts, refer to the literature Tetrahedron Lett., 1989, 30, 1927; J. Org. Chem., 2007, 72, 4067; J. Membr. Sci., 2017, 537, 151, using tetraethylurea Or pentaalkylguanidine and other raw materials; it is confirmed by proton nuclear magnetic resonance spectrum and carbon spectrum that it is the target product PTC3-6 composite base catalyst, as shown in Figures 5-12.

The quaternary ammonium salt type catalysts used in the comparative examples of the present invention are all commercially available.

The test method of the cyclic oligomer in the following examples of the present invention is specifically:

The experiment was carried out on a Waters-GPC size exclusion (SEC) chromatographic column. First, the prepared polysulfone resin was dissolved in chromatographically pure THF, and 20 μL (concentration of 0.4 wt%) was injected into the chromatographic column; mobile phase flow rate: 1.0 mL/min; detector: UV254; column temperature: 30°C; the calculation method of cyclic oligomer content adopts the normalization method: the peak area corresponding to the bicyclic oligomer and the peak area of the polymer and cyclic oligomer The ratio of the sum is the percentage of bicyclic oligomer; similarly, the ratio of the cyclic oligomer peak area to the sum of the peak areas of the polymer and cyclic oligomer is the percentage of cyclic oligomer.

Example 1

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass 50% KOH (100 mol) aqueous solution and 0.25 mol PTC1 composite base catalyst were heated to 140 °C, and the water separation reaction was carried out for 6 h; after the water separation was completed, 14.358 kg of 4,4'-dichlorodiphenyl sulfone dissolved in toluene was added. (50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 1 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.31%, and the total content of cyclic oligomers was 3.65%.

Example 2

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass The fraction is 50% KOH (100 mol) aqueous solution and 0.25 mol PTC2 composite base catalyst, the temperature is raised to 140 ° C, and the water separation reaction is performed for 6 hours; after the water separation is completed, 14.358 kg of 4,4'-dichlorodiphenylsulfone dissolved in toluene is added. (50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 2 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.25%, and the total cyclic oligomer content was 3.68%.

Example 3

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass The fraction is 50% KOH (100mol) aqueous solution and 0.25mol PTC3 composite base catalyst, the temperature is raised to 140 ° C, and the water separation reaction is performed for 6 hours; after the water separation is completed, 14.358 kg of 4,4'-dichlorodiphenylsulfone dissolved in toluene is added. (50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 3 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.31%, and the total content of cyclic oligomers was 4.41%.

Example 4

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass The fraction is 50% KOH (100 mol) aqueous solution and 0.25 mol PTC4 composite base catalyst, the temperature is raised to 140 ° C, and the water separation reaction is performed for 6 h; after the water separation is completed, 14.358 kg of 4,4'-dichlorodiphenylsulfone ( 50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 4 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.13%, and the total content of cyclic oligomers was 3.70%.

Example 5

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass The fraction is 50% KOH (100 mol) aqueous solution and 0.25 mol PTC5 composite base catalyst, the temperature is raised to 140 ° C, and the water separation reaction is performed for 6 h; after the water separation is completed, 14.358 kg of 4,4'-dichlorodiphenylsulfone ( 50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 5 of the present invention obtained polysulfone, and its infrared spectrum and hydrogen nuclear magnetic resonance spectrum are shown in Figures 13-14; the polysulfone prepared by the preparation method provided in Example 5 of the present invention has The gel chromatogram is shown in Figure 15, and the comprehensive peak statistics are shown in Tables 1-2; it can be seen that the bicyclic oligomer content of the polymer is 1.06%, and the total cyclic oligomer content is 3.51%.

Table 1 Comprehensive statistics of peak 1 in the gel chromatogram of polysulfone prepared by the preparation method provided in Example 5 of the present invention

name Retention time (minutes) Area (µV*sec) %area Height (microvolts) 1 Peak 1 12.579 61670561 98.94 330517 Mean 12.579 61670561.467 330516.821

Table 2 Comprehensive statistics of peak 2 in the gel chromatogram of polysulfone prepared by the preparation method provided in Example 5 of the present invention

name Retention time (minutes) Area (µV*sec) %area Height (microvolts) 1 Peak 2 19.865 660921 1.06 24430 Mean 19.865 660921.144 24429.666

Example 6

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass The fraction is 50% KOH (100 mol) aqueous solution and 0.25 mol PTC6 composite base catalyst, the temperature is raised to 140 ° C, and the water separation reaction is performed for 6 h; after the water separation is completed, 14.358 kg of 4,4'-dichlorodiphenylsulfone ( 50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 6 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.24%, and the total cyclic oligomer content was 4.43%.

Example 7

(1) 50L DMSO is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, add 11.451kg bisphenol A (50mol), be warming up to 80 ℃, after it is completely dissolved, add 11.222kg mass KOH (100mol) aqueous solution with a fraction of 50% and 0.1mol PTC5 composite base catalyst, heated to 140 ° C, water separation reaction 6h; 50mol), the temperature was raised to 160° C. and reacted for 1 to 3 hours, and the reaction was stopped when the polymerization viscosity reached 0.40 to 0.80 dL g ⁻¹ to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 7 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.19%, and the total cyclic oligomer content was 3.96%.

Example 8

(1) 50L DMAc is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, successively add 11.451kg bisphenol A (50mol), 14.358kg 4,4'-dichlorodiphenylsulfone (50mol) ), 14.51kg anhydrous K ₂ CO ₃ (105mol) and 0.25mol PTC5 composite base catalyst, heat up to 140°C, and conduct water separation reaction for 6h; The reaction was stopped with 0.80 dL g ^-1 to obtain a polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 8 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.34%, and the total content of cyclic oligomers was 3.97%.

Example 9

(1) 50L DMAc is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, successively add 11.451kg bisphenol A (50mol), 14.358kg 4,4'-dichlorodiphenylsulfone (50mol) ), 25.472kg anhydrous K ₃ PO ₄ (120mol) and 0.25mol PTC4 composite base catalyst, directly heated to 160 ℃ and reacted for 3～6h, when the polymerization viscosity reached 0.40～0.80dL g ^-1 , the reaction was stopped, and DMAc was used for dilution to obtain polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 9 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.63%, and the total content of cyclic oligomers was 4.31%.

Example 10

(1) 50L DMAc is injected in 100L reactor, then under nitrogen protection and stirring condition, in reactor, successively add 11.451kg bisphenol A (50mol), 14.358kg 4,4'-dichlorodiphenylsulfone (50mol) ), 25.472kg of anhydrous K ₃ PO ₄ (120mol) and 0.25mol of PTC5 composite base catalyst, directly heated to 160 ℃ and reacted for 3～6h, when the polymerization viscosity reached 0.40～0.80dL g ^-1 to stop the reaction, and diluted with DMAc to obtain polymer solution.

(2) Cool the reaction system to room temperature, and solidify and pulverize the polymer solution obtained in step (1) in water to obtain a white powdery polymer resin; Finally, granulation is carried out to obtain the target product.

After testing, the preparation method provided in Example 10 of the present invention obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.55%, and the total content of cyclic oligomers was 4.29%.

Comparative Example 1

The preparation method provided in Example 1 is adopted, except that the PTC1 composite base catalyst is not added.

After testing, the preparation method provided in Comparative Example 1 obtained polysulfone, and its gel chromatogram is shown in Figure 16, and the comprehensive peak statistics are shown in Tables 3-4; it can be seen that the bicyclic oligomer content of the polymer is 1.32 %, and the total content of cyclic oligomers is 4.58%.

Table 3 Comprehensive statistics of peak 1 in the gel chromatogram of polysulfone prepared by the preparation method provided in Comparative Example 1

name Retention time (minutes) Area (µV*sec) %area Height (microvolts) 1 Peak 1 12.054 61752463 98.68 350115 Mean 12.054 61752463.425 350114.674

Table 4 Comprehensive statistics of peak 2 in the gel chromatogram of polysulfone prepared by the preparation method provided in Comparative Example 1

name Retention time (minutes) Area (µV*sec) %area Height (microvolts) 1 Peak 2 19.992 825130 1.32 29502 Mean 19.992 825129.575 29502.496

Comparative Example 2

The preparation method provided in Example 1 is adopted, except that 0.25 mol of benzyl trimethyl ammonium chloride is used instead of 0.25 mol of PTC1 composite base catalyst.

After testing, the preparation method provided in Comparative Example 2 obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.49%, and the total content of cyclic oligomers was 5.32%.

Comparative Example 3

The preparation method provided in Example 1 is adopted, except that 0.25 mol of dodecyl trimethyl ammonium chloride is used instead of 0.25 mol of PTC1 composite base catalyst.

After testing, the preparation method provided in Comparative Example 3 obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.59%, and the total content of cyclic oligomers was 4.69%.

Comparative Example 4

The preparation method provided in Example 1 was adopted, except that 0.25 mol of tetrabutylammonium bromide was used instead of 0.25 mol of PTC1 composite base catalyst.

After testing, the preparation method provided in Comparative Example 4 obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.46%, and the total content of cyclic oligomers was 4.86%.

Comparative Example 5

The preparation method provided in Example 8 is adopted, except that the PTC5 composite base catalyst is not added.

After testing, the preparation method provided in Comparative Example 5 obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.57%, and the total content of cyclic oligomers was 4.71%.

Comparative Example 6

The preparation method provided in Example 9 is adopted, with the difference that: no PTC4 composite base catalyst is added.

After testing, the preparation method provided in Comparative Example 6 obtained polysulfone, and the bicyclic oligomer content of the polymer was 1.98%, and the total content of cyclic oligomers was 5.09%.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a preparation method of polysulfone resin, comprises the following steps: a) The bisphenol monomer, the salt-forming agent, the composite base catalyst and the dihalogen monomer are polymerized in a solvent to obtain a polymer solution; the composite base catalyst contains the structure represented by formula (I) or formula (II) ;

Formula (I);

formula (II); Wherein, -R ₁ is selected from -CH ₃ or

; -R ₂ is selected from -CH ₃ , -CH ₂ CH ₃ or

-R ₃ is selected from -CH ₃ , -CH ₂ CH ₃ ; b) The polymer solution obtained in step a) is solidified in water and then pulverized, and then washed with water, vacuum dried and granulated to obtain a polysulfone resin. 2. The preparation method according to claim 1, wherein the bisphenol monomer in step a) is selected from bisphenol A, bisphenol S or 4,4'-biphenol. 3 . The preparation method according to claim 1 , wherein the salt-forming agent in step a) is selected from one or more of NaOH, KOH, K ₂ CO ₃ and K ₃ PO ₄ . 4 . 4 . The preparation method according to claim 1 , wherein the consumption of the composite base catalyst described in step a) is 0.1% to 3% of the molar amount of the bisphenol monomer. 5 . 5. The preparation method according to claim 1, wherein the dihalogen monomer in step a) is selected from 4,4'-dichlorodiphenylsulfone, 4,4'-difluorodiphenylsulfone or 4,4'-Difluorobenzophenone. 6. The preparation method according to claim 1, wherein the molar ratio of the bisphenol monomer, the salt-forming agent and the dihalogen monomer described in step a) is 1:(2~3):(0.8~ 1.2). 7 . The preparation method according to claim 1 , wherein the temperature of the polymerization reaction in step a) is 70° C.˜220° C., and the time is 1 h˜15 h. 8 . 8. preparation method according to claim 1 is characterized in that, the process of the polymerization reaction described in step a) is specifically: Dissolving the bisphenol monomer in a solvent, adding a salt-forming agent and a composite alkali catalyst to carry out a water separation reaction, then adding a dihalogen monomer to heat up, and performing a first polycondensation reaction to obtain a polymer solution; Or adding bisphenol monomer, dihalogen monomer, salt-forming agent and composite base catalyst to the solvent to carry out water separation reaction, heating up, and carrying out the second polycondensation reaction to obtain a polymer solution; Or after adding the bisphenol monomer, the dihalogen monomer, the salt-forming agent and the composite alkali catalyst in sequence to the solvent, the temperature is raised, the third polycondensation reaction is carried out, and the polymer solution is obtained after dilution. 9 . The preparation method according to claim 8 , wherein the temperature of the water separation reaction is 110° C.˜150° C., and the time is 5 h˜7 h. 10 . 10 . The preparation method according to claim 1 , wherein the temperature of the vacuum drying in step b) is 100°C to 150°C, and the time is 20h to 30h. 11 .

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