An end-capped polysulfone resin and a method for its preparation

Abstract

This invention belongs to the field of polymer materials technology, specifically relating to a capped polysulfone resin and its preparation method. The method for preparing the capped polysulfone resin provided by this invention involves adding a capping agent to the polysulfone after obtaining a polymer mixture. The capping agent includes one or more of 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, 2-(trimethylsilyl)ethoxymethyl chloride, and chloromethyl methyl ether. Due to the change in the end-group structure, the steric hindrance increases, improving the temperature resistance and stability of the capped polysulfone resin. Simultaneously, the light transmittance of the capped polysulfone resin product is significantly improved, the haze is significantly reduced, the color is improved, the flowability is improved, and the corrosivity is reduced.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a capped polysulfone resin and its preparation method. Background Technology

[0002] Polysulfone resin has a high glass transition temperature and a wide range of applications, making it a promising polymer material. However, existing polysulfone production processes often result in polysulfone resins containing chlorine-terminated, hydroxyl-terminated, or metal-terminated groups. While resins with hydroxyl-terminated or metal-terminated groups are beneficial in the coatings industry, their use should be avoided in other applications. Furthermore, chlorine in chlorine-terminated groups is corrosive to injection molding equipment; therefore, end-group modification is essential. Chinese patent CN104530419A discloses an industrial synthesis method for a high thermal stability end-capped polysulfone resin, but the resulting end-capped polysulfone resin product exhibits poor optical properties. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a capped polysulfone resin and a method for preparing the same. The capped polysulfone resin product obtained by this invention has significantly improved light transmittance and significantly reduced haze.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing end-capped polysulfone resin, comprising the following steps:

[0006] Aromatic dihydroxy monomers, aromatic dihalogen sulfone monomers, dehydrating agents, alkali metal substances, and solvents are mixed and then subjected to a polymerization reaction to obtain a polymer mixture.

[0007] The polymer mixture, phase transfer catalyst, and end-capping agent are mixed and then refluxed to obtain a end-capped polymer mixture; the end-capping agent includes one or more of 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, 2-(trimethylsilyl)ethoxymethyl chloride, and chloromethyl methyl ether.

[0008] The end-capped polymer mixture is sequentially discharged, dispersed, crushed, washed, and dried to obtain the end-capped polysulfone resin.

[0009] Preferably, the amount of the capping agent is 1 to 10 wt% of the aromatic dihydroxy monomer.

[0010] Preferably, the aromatic dihydroxy monomer includes one or more of bisphenol A, bisphenol S, and 4,4'-biphenyl.

[0011] Preferably, the aromatic dihalogen sulfone monomer comprises 4,4'-dichlorodiphenyl sulfone and / or 4,4'-difluorodiphenyl sulfone.

[0012] Preferably, the molar ratio of the aromatic dihydroxy monomer to the aromatic dihalogen sulfone monomer is 1.01 to 1.05:1.

[0013] Preferably, the dehydrating agent includes one or more of toluene, xylene, ethylbenzene, and chlorobenzene.

[0014] Preferably, the alkali metal-containing substance includes alkali metal hydroxides and / or alkali metal salts.

[0015] Preferably, the polymerization reaction is carried out at a temperature of 150–270°C for 4–8 hours.

[0016] Preferably, the phase transfer catalyst comprises one or more of 18-crown ether-6, 15-crown-5, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, pyridine, and tributylamine.

[0017] The present invention also provides a capped polysulfone resin obtained by the preparation method described above, wherein the capping rate of the capped polysulfone resin is 80-95%.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The method for preparing end-capped polysulfone resin provided by this invention involves adding an end-capping agent to the polysulfone after obtaining a polymer mixture. The end-capping agent includes one or more of 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, 2-(trimethylsilyl)ethoxymethyl chloride, and chloromethyl methyl ether. Due to the change in the end group structure, the steric hindrance increases, thereby improving the temperature resistance and stability of the end-capped polysulfone resin. At the same time, the light transmittance of the end-capped polysulfone resin product is significantly improved, the haze is significantly reduced, the color is improved, the fluidity is improved, and the corrosivity is reduced.

[0020] The data from the examples show that the temperature resistance of the uncapped polysulfone resin product in the comparative example is 300-340°C, while the temperature resistance of the capped polysulfone resin product in the examples can be increased to 350-360°C; the melt flow rate of the capped polysulfone resin is increased by 10-30% compared with that of the uncapped product. Detailed Implementation

[0021] This invention provides a method for preparing end-capped polysulfone resin, comprising the following steps:

[0022] Aromatic dihydroxy monomers, aromatic dihalogen sulfone monomers, dehydrating agents, alkali metal substances, and solvents are mixed and then subjected to a polymerization reaction to obtain a polymer mixture.

[0023] The polymer mixture, phase transfer catalyst, and end-capping agent are mixed and then refluxed to obtain a end-capped polymer mixture; the end-capping agent includes one or more of 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, 2-(trimethylsilyl)ethoxymethyl chloride, and chloromethyl methyl ether.

[0024] The end-capped polymer mixture is sequentially discharged, dispersed, crushed, washed, and dried to obtain the end-capped polysulfone resin.

[0025] Unless otherwise specified, all materials and equipment used in this invention are commercially available products in the field.

[0026] This invention involves mixing aromatic dihydroxy monomers, aromatic dihalogen sulfone monomers, a dehydrating agent, an alkali metal substance, and a solvent, and then carrying out a polymerization reaction to obtain a polymer mixture.

[0027] In this invention, the aromatic dihydroxy monomer preferably includes one or more of bisphenol A, bisphenol S, and 4,4'-biphenyl.

[0028] In this invention, the aromatic dihalogen sulfone monomer preferably includes 4,4'-dichlorodiphenyl sulfone (DCPDS) and / or 4,4'-difluorodiphenyl sulfone (DFDPS).

[0029] In this invention, the preferred molar ratio of the aromatic dihydroxy monomer to the aromatic dihalogen sulfone monomer is 1.01 to 1.05:1. This molar ratio is beneficial for subsequent end-capping, improves product stability, and reduces corrosivity.

[0030] In this invention, the water-removing agent preferably includes one or more of toluene, xylene, ethylbenzene and chlorobenzene, more preferably toluene.

[0031] In this invention, the alkali metal-containing substance preferably includes alkali metal hydroxides and / or alkali metal salts, the alkali metal hydroxides preferably include sodium hydroxide and / or potassium hydroxide, and the alkali metal salts preferably include one or more of sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, and sodium hydride.

[0032] In this invention, the molar ratio of the alkali metal substance to the aromatic dihydroxy monomer is preferably 1.01 to 2:1.

[0033] In this invention, the solvent is preferably an aprotic polar solvent, which preferably includes one or more of dimethyl sulfoxide (DMSO), dimethyl sulfone, diphenyl sulfone (DPS), diethylene sulfoxide, sulfolane, tetrahydrothiophene-1-oxide, N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and 1,3-dimethyl-2-imidazolinone (DMI).

[0034] In this invention, the volume ratio of the water-removing agent to the solvent is preferably 5 to 100:100, more preferably 10 to 15:100.

[0035] In this invention, the polymerization temperature is preferably 150–270°C, more preferably 235°C, and the polymerization time is preferably adjusted according to the molecular weight of the polysulfone product to be prepared, preferably 4–8 h, more preferably 7 h; the polymerization reaction is preferably carried out under nitrogen protection, and the end groups of the polysulfone in the polymer mixture obtained after the polymerization reaction are mainly -OH, -ONa, or -halogen. If the aromatic dihalogen sulfone monomer is in excess, the end groups are mainly -halogen; if the aromatic dihydroxy monomer is in excess, the end groups are mainly -OH, and because of the excess alkali metal salt, -OH will be converted into -ONa.

[0036] After obtaining the polymer mixture, the present invention mixes the polymer mixture, phase transfer catalyst and end-capping agent and then refluxes the mixture to obtain a end-capped polymer mixture; the end-capping agent includes one or more of 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, 2-(trimethylsilyl)ethoxymethyl chloride and chloromethyl methyl ether.

[0037] In this invention, the polymer mixture, phase transfer catalyst and end-capping agent are preferably mixed by cooling the polymer mixture before mixing, and the temperature of the polymer mixture after cooling is preferably 100-120°C.

[0038] In this invention, the phase transfer catalyst preferably comprises one or more of 18-crown ether-6, 15-crown-5, benzyltriethylammonium chloride (TEBA), tetrabutylammonium bromide (TBAB), tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, pyridine, and tributylamine.

[0039] In this invention, the amount of the capping agent is preferably 1 to 10 wt% of the aromatic dihydroxy monomer, more preferably 5%.

[0040] In this invention, the amount of the phase transfer catalyst is preferably 1 to 10 wt% of an aromatic dihydroxy monomer, more preferably 5%.

[0041] In this invention, the reflux process is preferably accompanied by stirring, and the stirring speed is preferably 100-2000 rpm, more preferably 500-700 rpm; the reflux temperature is preferably 100-120°C, the reflux time is preferably 1-3 hours, and the reflux is preferably carried out under pressure, and the pressure is preferably 0.1-0.3 MPa.

[0042] After obtaining the end-capped polymer mixture, the present invention sequentially discharges, disperses, crushes, washes, and dries the end-capped polymer mixture to obtain the end-capped polysulfone resin.

[0043] The present invention does not have any special requirements for the methods of dispersing, crushing, washing and drying the materials; methods commonly used by those skilled in the art can be used.

[0044] The present invention also provides a capped polysulfone resin obtained by the preparation method described above, wherein the capping rate of the capped polysulfone resin is 80-95%.

[0045] In this invention, the end-capped polysulfone resin preferably includes end-capped ordinary bisphenol A type polysulfone, end-capped polyarylsulfone, end-capped polyether ether ketone, or end-capped polyether sulfone, and the end-capped polyarylsulfone preferably includes end-capped polyphenylsulfone.

[0046] To further illustrate the present invention, the end-capped polysulfone resin and its preparation method of the present invention are described in detail below with reference to embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0047] In this example, polyethersulfone is used as an example. The reaction formula for synthesizing polyethersulfone (before end-capping) is shown in Formula I:

[0048]

[0049] The structural formula of the obtained uncapped polyethersulfone is shown in Formula II:

[0050]

[0051] The structural formula of the end-capping agent 2-propoxychloroethane is shown in Formula III:

[0052]

[0053] The end groups of the obtained capped polyethersulfone are shown in Formula IV:

[0054]

[0055] Example 1

[0056] Polymerization was carried out in a four-necked flask at 235°C for 7 hours under nitrogen protection using 287.1600 g (1.0000 mol) of 4,4'-dichlorodiphenyl sulfone, 158.9850 g (1.5000 mol) of sodium carbonate, 1408.3100 g (11.7193 mol) of sulfolane and 250.2758 g (1.0200 mol) of bisphenol S (in excess). The mixture was then cooled to 100°C, and 12.5138 g of end-capping agent (2-propoxychloroethane) and 12.5138 g of phase transfer catalyst (benzyltriethylammonium chloride) were added to the flask. The mixture was stirred and refluxed at 100°C for 1 hour. After reflux was stopped, the mixture was discharged, dispersed, pulverized, washed, and dried to obtain end-capped polyethersulfone resin with an end-capping rate of 87.5%.

[0057] Example 2

[0058] The only difference from Example 1 is that the mass of bisphenol S is 257.7785 g (1.0300 mol), and all other conditions are the same. The end-capping rate of the obtained end-capped polyethersulfone resin is 88.3%.

[0059] Example 3

[0060] The only difference from Example 1 is that the capping agent used is 2-methoxyethoxymethyl chloride, and the capping rate of the resulting capped polyethersulfone resin is 91.2%.

[0061] Comparative Example 1

[0062] Polymerization of 4,4'-dichlorodiphenyl sulfone (287.1600 g, 1.0000 mol), sodium carbonate (158.9850 g, 1.5000 mol), sulfolane (1408.3100 g, 11.7193 mol), and bisphenol S (250.2758 g, 1.0200 mol) in excess was carried out in a four-necked flask under nitrogen protection at 235 °C for 7 h. The mixture was then cooled to 100 °C, dispersed, pulverized, washed, and dried to obtain uncapped polyethersulfone resin.

[0063] Comparative Example 2

[0064] Polymerization was carried out in a four-necked flask at 235°C for 7 h under nitrogen protection using 287.1600 g (1.0000 mol) of 4,4'-dichlorodiphenyl sulfone, 158.9850 g (1.5000 mol) of sodium carbonate, 1408.3100 g (11.7193 mol) of sulfolane and 250.2758 g (1.0200 mol) of bisphenol S (in excess). The mixture was cooled to 100°C, and then 12.5138 g of phase transfer catalyst (benzyltriethylammonium chloride) was added to the flask. End-capping agent (chloromethane) was introduced at 1 mL / min for 30 min while stirring. The mixture was then refluxed at 100°C for 1 h. After reflux was stopped, the mixture was discharged, dispersed, pulverized, washed, and dried to obtain end-capped polyethersulfone resin with an end-capping rate of 75%.

[0065] The performance test data of the polyethersulfone resins prepared in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1:

[0066] Table 1 Performance test data of polyethersulfone resin in Examples 1-3 and Comparative Examples 1-2

[0067]

[0068] As can be seen from the above examples and comparative data, the end-capping rate of the polysulfone resin prepared in the embodiments of the present invention is 80-95%. The melt flow rate of the polysulfone product after end-capping with an alkoxyalkyl ether structure is improved, the color is significantly improved, and other optical properties (including total transmittance and haze) are also improved. Moreover, the polysulfone resin end-capped with an alkoxyalkyl ether structure in the present invention can improve the temperature resistance and stability of the polysulfone product and reduce its corrosivity.

[0069] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing end-capped polysulfone resin, characterized in that, Includes the following steps: Aromatic dihydroxy monomer, aromatic dihalogen sulfone monomer, water-removing agent, alkali metal substance and solvent are mixed and then subjected to polymerization reaction to obtain polymer mixture; The polymer mixture, phase transfer catalyst, and capping agent are mixed and refluxed to obtain a capped polymer mixture; the capping agent is one or more selected from 2-methoxyethoxymethyl chloride, 2-propoxychloroethane, and chloromethyl methyl ether; the amount of the capping agent is 1-10 wt% of the aromatic dihydroxy monomer; The end-capped polymer mixture is sequentially discharged, dispersed, crushed, washed, and dried to obtain the end-capped polysulfone resin.

2. The preparation method according to claim 1, characterized in that, The aromatic dihydroxy monomer is one or more of bisphenol A, bisphenol S, and 4,4'-biphenyl.

3. The preparation method according to claim 1, characterized in that, The aromatic dihalogen sulfone monomer is 4,4'-dichlorodiphenyl sulfone and / or 4,4'-difluorodiphenyl sulfone.

4. The preparation method according to claim 1, 2 or 3, characterized in that, The molar ratio of the aromatic dihydroxy monomer to the aromatic dihalogen sulfone monomer is 1.01~1.05:

1.

5. The preparation method according to claim 1, characterized in that, The water-removing agent is one or more of toluene, xylene, ethylbenzene, and chlorobenzene.

6. The preparation method according to claim 1, characterized in that, The alkali metal-containing substance is an alkali metal hydroxide and / or an alkali metal salt.

7. The preparation method according to claim 1, characterized in that, The polymerization reaction is carried out at a temperature of 150~270℃ for 4~8 hours.

8. The preparation method according to claim 1, characterized in that, The phase transfer catalyst is one or more of 18-crown ether-6, 15-crown-5, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride.

9. The end-capped polysulfone resin obtained by the preparation method according to any one of claims 1 to 8, characterized in that, The end-capping rate of the polysulfone resin is 80-95%.

Images