Reaction aid for glycidyl ether synthesis as well as preparation method and application of reaction aid

Abstract

The invention discloses a reaction aid for glycidyl ether synthesis and a preparation method and application thereof, the reaction aid is polymer nanoparticles with a core-shell structure, and the reaction aid is prepared by an in-situ free radical polymerization method. The method comprises the following steps: synthesizing biphenyl glycidyl ether: carrying out etherification reaction on biphenyl diphenol and epoxy chloropropane under a catalytic condition to obtain an intermediate, and diluting with an organic solvent to obtain an intermediate diluent; emulsifying a sodium hydroxide solution containing a reaction aid, an organic solvent and a surfactant to obtain an emulsion; reacting the intermediate diluent with the emulsion to obtain a product solution; the product liquid enters a separation tank for demulsification, and biphenyl glycidyl ether is obtained from an organic phase; the reaction auxiliary agent is dispersed in a water phase, and is separated and recovered through a gel desalination column. The biphenyl glycidyl ether is synthesized by using the reaction aid, the process is simple and easy to control, the generation of organochlorine caused by incomplete cyclization reaction is inhibited, the organochlorine formed in the product is effectively removed, and the yield and quality of the product are improved.

Description

Technical Field

[0001] The invention relates to the field of epoxy resin synthesis, and in particular to a reaction auxiliary agent for glycidyl ether synthesis, a preparation method and application thereof. Background Art

[0002] Biphenyl glycidyl ether is an important category of epoxy resins. Its molecular structure contains chemically stable ether bonds and highly reactive epoxy groups, and the ether bonds and epoxy groups are separated by methylene groups. It also contains rigid biphenyl groups. The epoxy groups of biphenyl glycidyl ethers can react with a variety of nucleophilic reagents such as water, alcohols, amines, carboxylic acids, and thiols to open the ring structure and achieve chain extension. The unique molecular structure gives them many excellent properties, such as high glass transition temperature, strong toughness, low water absorption, low melt viscosity, high fracture strength, etc. The strength of the materials processed using biphenyl glycidyl ether as a monomer is comparable to that of steel. Thanks to the nematic molecular structure formed after polymerization, biphenyl glycidyl ethers are also used in the production and processing of liquid crystal materials. In addition, they are also widely used in the field of high-frequency electronic packaging materials.

[0003] At present, the industrial production of biphenyl glycidyl ether is mainly based on a two-step synthesis technology route, using biphenyl diphenol and epichlorohydrin as raw materials, and separating the etherification reaction and the cyclization reaction into independent units. This method has a high yield and a relatively simple post-processing process, but the following side reactions usually occur during the reaction process.

[0004] β reaction between phenolic hydroxyl group and epichlorohydrin in etherification reaction:

[0005]

[0006] Reaction of the above by-products with epichlorohydrin:

[0007]

[0008] Incomplete cyclization of chlorohydrin ether intermediates in cyclization reactions:

[0009]

[0010] The above side reactions cause the chlorine element to remain in the molecular structure in the form of organic chlorine, resulting in an increase in the chlorine content of the product and a decrease in the yield of the target product, while also reducing the quality of the product and the performance of its downstream materials.

[0011] Most of the existing research work on reducing the chlorine content of glycidyl ether epoxy resins has focused on the refined dechlorination of crude products. For example, Chinese patent CN113185671 discloses a method for removing impurities and purifying epoxy resins. First, a cation-bound zeolite molecular sieve is prepared and loaded into a fixed bed device as an adsorbent. Then, an epoxy resin fluid is injected for adsorption separation. This method can reduce the chlorine content of the epoxy resin from 800-1500 ppm to less than 400 ppm. However, the patent does not describe the adsorption capacity of the adsorbent and the regeneration process. Patent CN114989396 discloses a method for removing organic chlorine impurities in epoxy resin by using MOFs materials. MOFs materials with reduced metals are loaded as fixed phases on a grid inside a reactor. Epoxy resin fluid is passed into the reactor in an electromagnetic field to contact and react with the MOFs material. The polarization effect of chlorine-containing impurities and reduced metals of MOFs materials in the electromagnetic field is utilized to make the two highly reactive, and the chlorine content of epoxy resin can be reduced from 800-900ppm to between 200-300ppm. Similarly, the patent does not report on the processing capacity and regeneration process of the MOFs materials used. Chinese patent CN113024771 discloses a method for preparing a low total chlorine content epoxy resin, wherein a polyphenol / alcohol precursor, epichlorohydrin, a non-protonic polar solvent and a granular alkali metal hydroxide are mixed and reacted in a one-step process to obtain a crude product, and then the crude product is refined using a low-concentration alkaline aqueous solution to obtain a glycidyl ether epoxy resin monomer having a total chlorine content of less than 200 ppm.

[0012] At present, the industrial production of biphenyl glycidyl ether mainly adds a refining process after the main reaction, and the crude resin product obtained by synthesis is dechlorinated and refined. Although the refining reagent with strong alkalinity used can effectively remove the residual organic chlorine in the crude product, it will also cause certain damage to the epoxy groups in the formed product, thereby reducing the epoxy value and yield of the product while obtaining a low-chlorine content product.

[0013] Based on the above research status, it can be seen that the vast majority of research and production work focuses on achieving the purpose of dechlorination and chlorine reduction of products by adding later refining treatments, while there are no related studies based on the two-step technical route to directly synthesize biphenyl glycidyl ether epoxy resins with high yield and low chlorine content. Summary of the invention

[0014] The purpose of the present invention is to provide a synthetic reaction auxiliary for biphenyl type glycidyl ether and a preparation method thereof, as well as a synthetic method for biphenyl type glycidyl ether using the reaction auxiliary. After a two-step reaction, a product with a low chlorine content can be obtained by only conventional separation and purification operations without adding an additional refining step, thereby simplifying the process, ensuring a high yield of the product and improving the quality of the product.

[0015] The present invention provides a reaction aid for the synthesis of glycidyl ether and a preparation method thereof:

[0016] The reaction aid is a polymer nanoparticle with a core-shell structure, which is composed of a cross-linked gelatin core and a polyacrylamide shell. The core is a porous spherical structure, the shell is a loose mesh structure, and the particle size is between 50 and 100 nanometers.

[0017] The hydrophilic shell of the reaction aid ensures its dispersibility in the aqueous phase, while providing protection for the inner core, giving the system sufficient stability. The inner core is a porous and relatively hydrophobic environment, providing a suitable place for cyclization and dechlorination reactions, and inhibiting the occurrence of side reactions such as product self-polymerization and hydrolysis, which can provide auxiliary effects for the reaction;

[0018] The reaction aid has surface activity, and adding the reaction aid to the system is beneficial to the stability of the emulsion. The reaction aid has pH buffering capacity, which can inhibit the occurrence of side reactions such as secondary etherification or hydrolysis of the cyclized product caused by excessive alkalinity in the emulsion, reduce the amount of alkali used, and indirectly reduce the amount of wastewater generated during the synthesis process.

[0019] The preparation method of the reaction aid comprises the following steps:

[0020] The pre-prepared gelatin nanoparticles were dissolved in a phosphate buffer solution (50 mM, pH 7.4) to obtain a gelatin nanoparticle solution, and the gelatin concentration in the solution was determined by the BCA method; N-acryloxysuccinimide was added to the gelatin nanoparticle solution, and the mixture was stirred at 4 to 6° C. for 2 to 4 hours; small molecules in the system were filtered out by an ultrafiltration machine, and the filter membrane had a molecular weight cutoff of 1.0w, and the retained matter was diluted with pure water to obtain a modified gelatin nanoparticle solution; acrylamide and N,N-methylenebisacrylamide were added to the modified gelatin nanoparticle solution in sequence, and the mixture was stirred to dissolve and fully mixed to obtain the prepared liquid; adding ammonium persulfate and tetramethylethylenediamine to the prepared liquid to initiate polymerization, stirring and reacting at 20-25° C. for 2-4 hours; after the reaction, filtering the reaction liquid by ultrafiltration centrifugation to remove small molecules and oligomers in the system, the filter membrane has a molecular weight cutoff of 10.0w, and diluting the retentate with pure water to obtain a crude solution; using pure water as an eluent, passing the crude solution through an agarose gel desalting column under pressure, collecting the elution at the bottom of the column, freeze-drying at -50--60° C., and grinding into powder to obtain the finished product of the reaction aid.

[0021] In the above-mentioned preparation method, the concentration of the gelatin nanoparticle solution is 2% to 5%, and the mass ratio of N-acryloxysuccinimide to gelatin is 1:20 to 30.

[0022] In the above preparation method, the concentration of the modified gelatin nanoparticle solution is 2% to 5%, and the mass ratio of gelatin, acrylamide, N,N-methylenebisacrylamide, ammonium persulfate and tetramethylethylenediamine is 1:6.0 to 8.0:0.5 to 1.0:0.2 to 0.5:0.2 to 0.5.

[0023] In the above preparation method, the concentration of the crude product solution is 5%-8%.

[0024] In the above preparation method, the agarose gel desalting column filler is GE Sepharose CL-4B, the pressure condition is 0.020-0.025 MPa, and the mobile phase volume space velocity is 0.5-1.0 h -1 Among them, GE Sepharose CL-4B is available on the market, and the manufacturer is GE (General Electric).

[0025] The BCA method is a commonly used method for determining protein concentration. Its principle is based on the ability of peptide bonds in protein molecules to react with Cu under alkaline conditions. 2+ Complexation to form a complex, while Cu 2+ Reduction to Cu +Compared with the traditional Lowry method, this method is simpler to operate, the reagents are more stable, there is almost no influence of interfering substances, and it has higher sensitivity. The trace detection can reach 0.5μg / ml, and the application is more flexible.

[0026] The present invention also provides a method for synthesizing biphenyl glycidyl ether, comprising the following steps:

[0027] Step S1, adding biphenyl type dihydric phenol, epichlorohydrin and phase transfer catalyst into an etherification reaction kettle, reacting under certain conditions, then reducing pressure to recover excess epichlorohydrin in the system, adding organic solvent to the obtained intermediate for dilution, and obtaining an intermediate dilution liquid.

[0028] Step S2, adding a sodium hydroxide aqueous solution containing a reaction aid, an organic solvent and a surfactant into an emulsification tank, and obtaining an emulsion after ultrasonic emulsification.

[0029] Step S3, adding the intermediate dilution liquid and the emulsion into a cyclization reaction kettle, reacting under certain conditions to obtain a product liquid.

[0030] Step S4, adding the product liquid into a separation tank for demulsification, separating the lower aqueous phase, washing the upper organic phase with water, recovering the solvent under reduced pressure to obtain a crude product, washing the crude product with an alcohol solvent, drying and grinding it into powder to obtain the corresponding product, biphenyl glycidyl ether.

[0031] In the above-mentioned synthesis method, in step S1, the phase transfer catalyst is one of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride;

[0032] The molar ratio of biphenyl type diphenol, epichlorohydrin and phase transfer catalyst is 1.0:7.0-26.0:0.01-0.1, the reaction temperature is 60-100°C, the reaction time is 1-4 hours, the etherification reaction kettle has a condensation reflux device, and the reaction is carried out under nitrogen protection;

[0033] The organic solvent is one of toluene, xylene and methyl isobutyl ketone, and the mass ratio of the intermediate to the organic solvent is 1.0:0.8-1.0.

[0034] In step S1, after the etherification reaction is completed, the excess epichlorohydrin in the system is recovered to prevent it from entering the cyclization reaction and causing unnecessary side reactions such as etherification and hydrolysis under alkaline catalysis, which is beneficial to inhibiting the formation of organic chlorine.

[0035] In the above-mentioned synthesis method, in step S2, the reaction aid is a polymer nanoparticle with a core-shell structure, the mass concentration of the sodium hydroxide aqueous solution is 10% to 30%, the organic solvent is the same as the organic solvent in step S1, and the surfactant is one of sodium dodecylbenzene sulfonate, sodium lauroyl isethionate and sodium diisooctyl sulfosuccinate;

[0036] The mass ratio of the reaction aid to sodium hydroxide in the sodium hydroxide aqueous solution containing the reaction aid is 1.0:6.5-15.0, and the mass ratio of the sodium hydroxide aqueous solution, the organic solvent and the surfactant is 1.0:1.5-5.5:0.02-0.05.

[0037] In the above-mentioned synthesis method, in step S3, the mass ratio of the intermediate diluent and the emulsion is 1.0:1.5-3.0, the reaction temperature is 60-120°C, preferably, the reaction temperature is 80-110°C, within the preferred temperature range, the cyclization reaction of the chlorohydrin ether intermediate and the removal reaction of the organic chlorine can occur efficiently at the same time, and the refined dechlorination process is also completed after the cyclization reaction is completed. The reaction time is 2-6 hours, and the cyclization reactor has a condensation reflux device.

[0038] In the above-mentioned synthesis method, in step S4, the product liquid demulsification condition is to stand at room temperature in a separation tank for 1 to 4 hours and the vacuum degree is -0.01 to -0.09 MPa.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The aqueous phase is uniformly dispersed in the organic phase by emulsification, which enhances the mixing degree of the two-phase system and is beneficial to the contact and conversion of the raw materials; the reaction aid can be used as a mass transfer medium to assist the mutual contact of materials in the organic / aqueous phase, and the internal space of the reaction aid can provide a suitable place for the reaction; the reaction aid has both surface activity and pH buffering properties, which inhibits the occurrence of side reactions and reduces the amount of alkali used; the cyclization reaction and the dechlorination reaction are carried out simultaneously, and after the reaction process is completed, a low-chlorine product can be obtained through simple conventional separation and purification operations without the need for additional refining steps; during the reaction process, at a certain reaction temperature, as the electrolyte concentration and the oil-water ratio in the system change, the reaction liquid can complete demulsification and stratification under appropriate conditions after the reaction is completed; the reaction aid is dispersed in the aqueous phase and can be separated and recovered through subsequent desalination and dehydration treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a two-step synthetic route for biphenyl glycidyl ether.

[0042] Figure 2 Microscopic photograph of the reaction aid taken with a transmission electron microscope. DETAILED DESCRIPTION

[0043] The present invention is further illustrated below in conjunction with the examples, but is not intended to further limit the present invention.

[0044] Example 1

[0045] Preparation of reaction aids

[0046] 10 g of prefabricated gelatin nanoparticles were dispersed in 300 mL of phosphate buffer solution (50 mM, pH 7.4) to obtain a gelatin nanoparticle dispersion, to which 0.5 g of N-acryloyloxysuccinimide was added, and the mixture was stirred at 4 °C for 4 hours. The solution was concentrated by ultrafiltration and centrifugation, and the molecular weight cutoff was 1.0w (i.e., 1.0×10 4 ) and then diluted with pure water to a concentration of 4%. 60 g acrylamide and 6 g N,N-methylenebisacrylamide were added to the modified gelatin nanoparticle solution in sequence, dissolved and mixed to obtain a preparation solution, and then 2 g ammonium persulfate and 2 g tetramethylethylenediamine were added thereto to initiate polymerization. The reaction was stirred at 25°C for 2 hours. After the reaction was completed, the reaction solution was concentrated by ultrafiltration and centrifugation, and the molecular weight cutoff was 10.0w (i.e., 10.0×10 4 )) is then diluted with pure water to a concentration of 5% to obtain a crude solution, which is then desalted, freeze-dried and ground to obtain a finished reaction aid.

[0047] Example 2

[0048] Preparation of reaction aids

[0049] 10g of prefabricated gelatin nanoparticles were dispersed in 250mL of phosphate buffer solution (50mM, pH7.4) to obtain a gelatin nanoparticle dispersion, 0.4g of N-acryloyloxysuccinimide was added thereto, and the mixture was stirred and reacted at 6°C for 3 hours. The solution was concentrated by ultrafiltration and centrifugation (molecular weight cutoff 1.0w), and then diluted with pure water to a concentration of 5%. 80g of acrylamide and 9g of N,N-methylenebisacrylamide were added to the modified gelatin nanoparticle solution in sequence, and the mixture was dissolved and mixed to obtain a preparation solution, 4g of ammonium persulfate and 4g of tetramethylethylenediamine were added thereto to initiate polymerization, and the mixture was stirred and reacted at 20°C for 4 hours. After the reaction was completed, the reaction solution was concentrated by ultrafiltration and centrifugation (molecular weight cutoff 10.0w), and then diluted with pure water to a concentration of 7% to obtain a crude solution, which was then desalted, freeze-dried, ground and sieved to obtain a finished reaction aid.

[0050] Example 3

[0051] Synthesis of 4,4'-Biphenyl Diphenol Diglycidyl Ether

[0052] 300g of 4,4′-biphenyldiphenol, 1200g of epichlorohydrin and 15g of tetrabutylammonium bromide were put into the etherification reactor, nitrogen was introduced for protection, and the reaction was carried out at 80°C for 4 hours. The system was gradually heated to 115°C under a negative pressure of -0.09MPa, and the excess epichlorohydrin was recovered under reduced pressure. 450g of methyl isobutyl ketone was added to the intermediate obtained to obtain an intermediate dilution solution; 110g of sodium hydroxide was dissolved in 550g of pure water to prepare an alkaline solution, 8g of the reaction aid obtained in Example 1 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid and 1500g of methyl isobutyl ketone and 25g of sodium lauroyl isethionate were put into an emulsification tank for ultrasonic emulsification. The emulsion was obtained; the intermediate dilution liquid and the emulsion were added into a cyclization reaction kettle in a confluence and combination manner, and reacted at 100° C. for 4 hours to obtain a product liquid; the product liquid was added into a separation tank, and allowed to stand at room temperature and -0.04 MPa to demulsify and stratify, and the lower aqueous phase was separated, the organic phase was washed with pure water until the pH was neutral, and the methyl isobutyl ketone was recovered under reduced pressure, and the residue was washed with isopropanol for several times and then dried and ground to obtain a white powder product with a yield of 95.3% and a total chlorine content of 0.041%.

[0053] Example 4

[0054] Synthesis of 3,3′,5,5′-Tetramethyl-4,4′-Biphenylphenol Diglycidyl Ether

[0055] 300 g of 3,3′,5,5′-tetramethyl-4,4′-biphenol, 2400 g of epichlorohydrin and 10 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 3 hours. The system was gradually heated to 115° C. under a negative pressure of -0.09 MPa, and excess epichlorohydrin was recovered under reduced pressure. 500 g of toluene was added to the intermediate to obtain an intermediate dilution solution; 110 g of sodium hydroxide was dissolved in 500 g of pure water to prepare an alkaline solution, 10 g of the reaction aid obtained in Example 1 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid, 1200 g of toluene, and 20 g of sodium dodecylbenzene sulfonate were put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution solution and the emulsion were put into a cyclization reactor in a confluence and merging manner, and reacted at 110° C. for 5 hours to obtain a product liquid; the product liquid was put into a separation tank, and allowed to stand at room temperature and -0.02 MPa to demulsify and stratify, and the lower aqueous phase was separated. The organic phase was washed with pure water until the pH was neutral, and toluene was recovered under reduced pressure. The residue was washed with isopropanol several times and then dried and ground to obtain a white powder product with a yield of 94.9% and a total chlorine content of 0.048%.

[0056] Example 5

[0057] Synthesis of 3,3′,5,5′-Tetraethyl-4,4′-Biphenylphenol Diglycidyl Ether

[0058] 300 g of 3,3′,5,5′-tetraethyl-4,4′-biphenol, 1500 g of epichlorohydrin and 13 g of tetrabutylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 100° C. for 2 hours. The system was gradually heated to 115° C. under a negative pressure of -0.09 MPa, and the excess epichlorohydrin was recovered under reduced pressure. 520 g of xylene was added to the intermediate to obtain an intermediate dilution solution; 110 g of sodium hydroxide was dissolved in 450 g of pure water to prepare an alkaline solution, 11 g of the reaction aid obtained in Example 2 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid, 1300 g of xylene, and 25 g of sodium diisooctyl sulfosuccinate were put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution solution and the emulsion were put into a cyclization reactor in a confluence and merging manner, and reacted at 120° C. for 3 hours to obtain a product liquid; the product liquid was put into a separation tank, and allowed to stand at room temperature and -0.07 MPa for demulsification and stratification, and the lower aqueous phase was separated. The organic phase was washed with pure water until the pH was neutral, and the xylene was recovered under reduced pressure. The residue was washed with ethanol several times and then dried and ground to obtain a white powder product with a yield of 93.5% and a total chlorine content of 0.055%.

[0059] Example 6

[0060] Synthesis of 3,3′,5,5′-Tetraisopropyl-4,4′-Biphenylphenol Diglycidyl Ether

[0061] 300 g of 3,3′,5,5′-tetraisopropyl-4,4′-biphenol, 2200 g of epichlorohydrin and 15 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 4 hours. The system was gradually heated to 115°C under a negative pressure of -0.09MPa, and the excess epichlorohydrin was recovered under reduced pressure. 480g of toluene was added to the intermediate to obtain an intermediate dilution solution; 110g of sodium hydroxide was dissolved in 500g of pure water to prepare an alkaline solution, 10g of the reaction aid obtained in Example 2 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid, 1250g of toluene, and 22g of sodium dodecylbenzene sulfonate were put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution solution and the emulsion were put into a cyclization reactor in a confluence and merging manner, and reacted at 110°C for 5 hours to obtain a product liquid; the product liquid was put into a separation tank, and stood at room temperature and -0.02MPa for demulsification and stratification, and the lower aqueous phase was separated. The organic phase was washed with pure water until the pH was neutral, and toluene was recovered under reduced pressure. The residue was washed with isopropanol several times and then dried and ground to obtain an off-white powder product with a yield of 91.2% and a total chlorine content of 0.060%. .

[0062] Example 7

[0063] Synthesis of 2,2′,3,3′,5,5′-Hexamethyl-4,4′-biphenylphenol diglycidyl ether

[0064] 300 g of 2,2′,3,3′,5,5′-hexamethyl-4,4′-biphenol, 2680 g of epichlorohydrin and 11 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 3 hours. The system was gradually heated to 115° C. under a negative pressure of -0.09 MPa, and the excess epichlorohydrin was recovered under reduced pressure. 550 g of toluene was added to the intermediate to obtain an intermediate dilution solution; 120 g of sodium hydroxide was dissolved in 550 g of pure water to prepare an alkaline solution, 15 g of the reaction aid obtained in Example 1 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid, 1380 g of toluene, and 22 g of sodium dodecylbenzene sulfonate were put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution solution and the emulsion were put into a cyclization reactor in a confluence and merging manner, and reacted at 110° C. for 5 hours to obtain a product liquid; the product liquid was put into a separation tank, and allowed to stand at room temperature and -0.02 MPa to break the emulsion and decompose the layers, and the lower aqueous phase was separated. The organic phase was washed with pure water until the pH was neutral, and the toluene was recovered under reduced pressure. The residue was washed with isopropanol several times and then dried and ground to obtain a white powder product with a yield of 91.0% and a total chlorine content of 0.040%.

[0065] Comparative Example 1

[0066] Synthesis of 4,4'-Biphenyl Diphenol Diglycidyl Ether

[0067] The difference between the technical solution of Comparative Example 1 and the technical solution of Example 3 is that the sodium hydroxide solution is not emulsified, and no surfactant is added. The sodium hydroxide solution containing the reaction aid is simply mixed with the organic solvent and reacts with the intermediate dilution solution in a confluence and merging manner, as follows:

[0068] 300 g of 4,4′-biphenyldiphenol, 1200 g of epichlorohydrin and 15 g of tetrabutylammonium bromide were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 80° C. for 4 hours. The system was gradually heated to 115° C. under a negative pressure of -0.09 MPa, and the excess epichlorohydrin was recovered under reduced pressure. 450 g of methyl isobutyl ketone was added to the intermediate to obtain an intermediate dilution solution; 110 g of sodium hydroxide was dissolved in 550 g of pure water to prepare an alkaline solution, 8 g of the reaction aid obtained in Example 1 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid and 1500 g of methyl isobutyl ketone were stirred evenly to obtain a mixed solution; the intermediate dilution solution and the mixed solution were added into a cyclization reactor in a confluence and merging manner, and reacted at 100° C. for 4 hours to obtain a product liquid; the product liquid was added into a separation tank, and allowed to stand at room temperature and -0.04 MPa to demulsify and stratify, and the lower aqueous phase was separated. The organic phase was washed with pure water until the pH was neutral, and the methyl isobutyl ketone was recovered under reduced pressure. The residue was washed with isopropanol several times and then dried and ground to obtain a white powder product with a yield of 89.3% and a total chlorine content of 0.074%.

[0069] Comparative Example 2

[0070] Synthesis of 3,3′,5,5′-Tetramethyl-4,4′-Biphenylphenol Diglycidyl Ether

[0071] The difference between the technical solution of Comparative Example 2 and the technical solution of Example 4 is that the sodium hydroxide solution is not emulsified, and no surfactant is added. The sodium hydroxide solution containing the reaction aid is simply mixed with the organic solvent and reacts with the intermediate dilution solution in a confluence and merging manner, as follows:

[0072] 300 g of 3,3′,5,5′-tetramethyl-4,4′-biphenol, 2400 g of epichlorohydrin and 10 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 3 hours. The system was gradually heated to 115° C. under a negative pressure of -0.09 MPa, and excess epichlorohydrin was recovered under reduced pressure. 500 g of toluene was added to the intermediate to obtain an intermediate dilution solution; 110 g of sodium hydroxide was dissolved in 500 g of pure water to prepare an alkaline solution, 10 g of the reaction aid obtained in Example 1 was added thereto and mixed evenly, and the alkaline solution containing the reaction aid and 1200 g of toluene were stirred evenly to obtain a mixed solution; the intermediate dilution solution and the mixed solution were added into a cyclization reactor in a confluence and merging manner, and reacted at 110° C. for 5 hours to obtain a product liquid; the product liquid was added into a separation tank, and allowed to stand at room temperature and -0.02 MPa to separate the lower aqueous phase, and the organic phase was washed with pure water until the pH was neutral, and toluene was recovered under reduced pressure. The residue was washed with isopropanol several times and then dried and ground to obtain a pure white powder product with a yield of 86.5% and a total chlorine content of 0.078%.

[0073] Comparative Example 3

[0074] Synthesis of 3,3′,5,5′-Tetraethyl-4,4′-Biphenylphenol Diglycidyl Ether

[0075] The difference between the technical solution of Comparative Example 3 and the technical solution of Example 5 is that no reaction aid is added to the sodium hydroxide solution, and the emulsion is directly emulsified with the organic solvent and the surfactant to obtain an emulsion, and then reacted with the intermediate dilution solution in a confluence and merging manner, as follows:

[0076] 300 g of 3,3′,5,5′-tetraethyl-4,4′-biphenol, 1500 g of epichlorohydrin and 13 g of tetrabutylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 100° C. for 2 hours. The system is gradually heated to 115° C. under a negative pressure of -0.09 MPa, and excess epichlorohydrin is recovered under reduced pressure. 520 g of xylene is added to the obtained intermediate to obtain an intermediate dilution liquid; 110 g of sodium hydroxide is dissolved in 450 g of pure water to prepare an alkaline solution, and the alkaline solution, 1300 g of xylene and 25 g of sodium diisooctyl sulfosuccinate are put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution liquid and the emulsion are put into a cyclization reactor in a converging and merging manner, and reacted at 120° C. for 3 hours to obtain a product liquid; the product liquid is put into a separation tank, and is allowed to stand at room temperature and -0.07 MPa for demulsification and stratification, and a lower aqueous phase is separated. After the organic phase is washed with pure water until the pH is neutral, xylene is recovered under reduced pressure, and the residue is washed with ethanol for several times and then dried and ground to obtain a white powder product with a yield of 85.7% and a total chlorine content of 0.098%.

[0077] Comparative Example 4

[0078] Synthesis of 3,3′,5,5′-Tetraisopropyl-4,4′-Biphenylphenol Diglycidyl Ether

[0079] The difference between the technical solution of Comparative Example 4 and the technical solution of Example 6 is that no reaction aid is added to the sodium hydroxide solution, and the emulsion is directly emulsified with the organic solvent and the surfactant to obtain an emulsion, and then reacted with the intermediate dilution solution in a confluence and merging manner, as follows:

[0080] 300 g of 3,3′,5,5′-tetraisopropyl-4,4′-biphenol, 2200 g of epichlorohydrin and 15 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 4 hours. The system is gradually heated to 115° C. under a negative pressure of -0.09 MPa, and excess epichlorohydrin is recovered under reduced pressure. 480 g of toluene is added to the obtained intermediate to obtain an intermediate dilution liquid; 110 g of sodium hydroxide is dissolved in 500 g of pure water to prepare an alkaline solution, and the alkaline solution, 1250 g of toluene and 22 g of sodium dodecylbenzene sulfonate are put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution liquid and the emulsion are put into a cyclization reaction kettle in a confluence and merging manner, and reacted at 110° C. for 5 hours to obtain a product liquid; the product liquid is put into a separation tank, and is allowed to stand at room temperature and -0.02 MPa to break the emulsion and decompose the layers, and the lower aqueous phase is separated. After the organic phase is washed with pure water until the pH is neutral, the toluene is recovered under reduced pressure, and the residue is washed with isopropanol for several times and then dried and ground to obtain an off-white powder product with a yield of 84.1% and a total chlorine content of 0.105%.

[0081] Comparative Example 5

[0082] Synthesis of 2,2′,3,3′,5,5′-Hexamethyl-4,4′-biphenylphenol diglycidyl ether

[0083] The difference between the technical solution of Comparative Example 5 and the technical solution of Example 7 is that no reaction aid is added to the sodium hydroxide solution, and the emulsion is directly emulsified with the organic solvent and the surfactant to obtain an emulsion, and then reacted with the intermediate dilution solution in a confluence and merging manner, as follows:

[0084] 300 g of 2,2′,3,3′,5,5′-hexamethyl-4,4′-biphenol, 2680 g of epichlorohydrin and 11 g of benzyltriethylammonium chloride were put into an etherification reaction kettle, nitrogen was introduced for protection, and the reaction was carried out at 90° C. for 3 hours. The system is gradually heated to 115° C. under a negative pressure of -0.09 MPa, and excess epichlorohydrin is recovered under reduced pressure. 550 g of toluene is added to the obtained intermediate to obtain an intermediate dilution liquid; 120 g of sodium hydroxide is dissolved in 550 g of pure water to prepare an alkaline solution, and the alkaline solution, 1380 g of toluene and 22 g of sodium dodecylbenzene sulfonate are put into an emulsification tank for ultrasonic emulsification to obtain an emulsion; the intermediate dilution liquid and the emulsion are put into a cyclization reaction kettle in a confluence and merging manner, and reacted at 110° C. for 5 hours to obtain a product liquid; the product liquid is put into a separation tank, and is allowed to stand at room temperature and -0.02 MPa for demulsification and stratification, and a lower aqueous phase is separated. After the organic phase is washed with pure water until the pH is neutral, toluene is recovered under reduced pressure, and the residue is washed with isopropanol for several times and then dried and ground to obtain a white powder product with a yield of 83.5% and a total chlorine content of 0.091%.

[0085] It can be seen from the results of the embodiments and comparative examples that, compared with the existing biphenyl type glycidyl ether synthesis method, the product yield synthesized by the method reported in the present invention is improved, and the chlorine content of the product is significantly reduced, and a biphenyl type glycidyl ether product with a low chlorine content can be obtained while ensuring a high yield. In addition, the synthesis method of the present invention integrates the cyclization reaction with the refined dechlorination reaction, so that the process is effectively simplified.

[0086] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A reaction aid for the synthesis of glycidyl ether, characterized in that: The reaction aid is a polymer nanoparticle with a core-shell structure, which is composed of a cross-linked gelatin core and a polyacrylamide shell. The core is a porous spherical structure, the shell is a loose mesh structure, and the particle size is between 50 and 100 nanometers.

2. A method for preparing a reaction aid for the synthesis of glycidyl ether, characterized in that: The pre-prepared gelatin nanoparticles are dissolved in a phosphate buffer solution with a concentration of 50 mM and a pH of 7.4 to obtain a gelatin nanoparticle solution, and the gelatin concentration in the solution is determined by a BCA method; N-acryloyloxysuccinimide is added to the gelatin nanoparticle solution, and the mixture is stirred at 4 to 6° C. for 2 to 6 hours; small molecules in the system are filtered out by an ultrafiltration machine, and the filter membrane has a molecular weight cutoff of 1.0w, and the retentate is diluted with pure water to obtain a modified gelatin nanoparticle solution; Acrylamide and N,N-methylenebisacrylamide are sequentially added to the modified gelatin nanoparticle solution, stirred to dissolve and fully mixed to obtain a preparation solution; ammonium persulfate and tetramethylethylenediamine are added to the preparation solution to initiate polymerization, and the reaction is stirred at 20-25°C for 2-4 hours; after the reaction is completed, the reaction solution is filtered through ultrafiltration centrifugation to remove small molecules and oligomers in the system, the filter membrane has a molecular weight cutoff of 10.0w, and the intercepted matter is diluted with pure water to obtain a crude solution; pure water is used as an eluent, the crude solution is passed through an agarose gel desalting column under pressure, the elution at the bottom of the column is collected, freeze-dried at -50--60°C, and ground into powder to obtain the finished product of the reaction aid.

3. The method for preparing a reaction aid for glycidyl ether synthesis according to claim 2, characterized in that: The concentration of the gelatin nanoparticle solution is 2% to 5%, and the mass ratio of N-acryloxysuccinimide to gelatin is 1:(20 to 30).

4. The method for preparing a reaction aid for glycidyl ether synthesis according to claim 2, characterized in that: The concentration of the modified gelatin nanoparticle solution is 2% to 5%, and the mass ratio of gelatin, acrylamide, N,N-methylenebisacrylamide, ammonium persulfate and tetramethylethylenediamine is 1:(6.0 to 8.0):(0.5 to 1.0):(0.2 to 0.5):(0.2 to 0.5).

5. The method for preparing a reaction aid for glycidyl ether synthesis according to claim 2, characterized in that: The concentration of the crude product solution is 5% to 8%.

6. The method for preparing a reaction aid for glycidyl ether synthesis according to claim 2, characterized in that: The agarose gel desalting column filler is GE Sepharose CL-4B, the pressurization condition is 0.020MPa-0.025MPa, and the mobile phase volume space velocity is 0.5-1.0h -1 .

7. A method for synthesizing biphenyl glycidyl ether, characterized in that: The following steps are involved: Step S1, adding biphenyl type dihydric phenol, epichlorohydrin and phase transfer catalyst into an etherification reaction kettle to react, then reducing the pressure to recover excess epichlorohydrin in the system, adding an organic solvent to dilute the obtained intermediate to obtain an intermediate dilution liquid; Step S2, adding a sodium hydroxide aqueous solution containing the reaction aid for synthesis of glycidyl ether according to claim 1, an organic solvent and a surfactant into an emulsification tank, and obtaining an emulsion after ultrasonic emulsification; Step S3, adding the intermediate dilution liquid and the emulsion into a cyclization reaction kettle to react to obtain a product liquid; Step S4, adding the product liquid into a separation tank for demulsification, separating the lower aqueous phase, washing the upper organic phase with water, recovering the solvent under reduced pressure to obtain a crude product, washing the crude product with an alcohol solvent, filtering and drying to obtain the corresponding biphenyl type glycidyl ether solid product.

8. The method for synthesizing biphenyl glycidyl ether according to claim 7, characterized in that: In step S1, the biphenyl type dihydric phenol used has the following general structural formula: In the formula, the substituent R1 is one of H, methyl, ethyl, and isopropyl, and the substituent R2 = R1 or H; The phase transfer catalyst is one of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride, the molar ratio of biphenyl diphenol, epichlorohydrin and phase transfer catalyst is 1.0:(7.0-26.0):(0.01-0.1), the reaction temperature is 60-100°C, the reaction time is 1-4 hours, the etherification reaction kettle has a condensation reflux device, and the reaction is carried out under nitrogen protection; The organic solvent is one of toluene, xylene and methyl isobutyl ketone, and the mass ratio of the intermediate to the organic solvent is 1.0:(0.8-1.0).

9. The method for synthesizing biphenyl glycidyl ether according to claim 7, characterized in that: In step S2, the reaction aid is a polymer nanoparticle with a core-shell structure, the mass concentration of the sodium hydroxide aqueous solution is 10% to 30%, the organic solvent is the same as the organic solvent in step S1, and the surfactant is one of sodium dodecylbenzene sulfonate, sodium lauroyl isethionate and sodium dioctyl sulfosuccinate; In the sodium hydroxide aqueous solution containing the reaction aid, the mass ratio of the reaction aid to sodium hydroxide is 1.0:6.5-15.0, and the mass ratio of the sodium hydroxide aqueous solution, the organic solvent and the surfactant is 1.0:1.5-5.5:0.02-0.

05.

10. The method for synthesizing biphenyl glycidyl ether according to claim 1, characterized in that: In step S3, the mass ratio of the intermediate dilution liquid and the emulsion is 1.0:1.5~3.0, the reaction temperature is 60~120°C, the reaction time is 2~6 hours, and the cyclization reactor is provided with a condensation reflux device; in step S4, the product liquid demulsification condition is to stand at room temperature in a separation tank for 1~4 hours, and the vacuum degree is -0.01~-0.09MPa.

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