CN114940752B - Catalyst for epoxy ring-opening polymerization and its preparation method and application - Google Patents

Abstract

The invention provides a catalyst for epoxy ring-opening polymerization and its preparation method and application. The preparation method comprises the following steps: mixing a carrier, an active component and a solvent, drying after mixing, and grinding to obtain the epoxy ring-opening A catalyst for polymerization, the carrier includes boron nitride and/or modified boron nitride. By coordinating the carrier with the active component, the reactivity of the ring-opening polymerization of epoxy compounds can be improved and the polymerization rate can be increased. Therefore, the catalyst obtained by the preparation method provided by the invention has strong catalytic activity and is suitable for the ring-opening polymerization of epoxy compounds reaction.

Description

Catalyst for epoxy ring-opening polymerization, preparation method and application thereof

technical field

The invention belongs to the technical field of catalyst preparation, and relates to a catalyst for epoxy ring-opening polymerization, a preparation method and application thereof.

Background technique

Polyether is a class of polymer materials widely used in the fields of synthetic polyurethane, lithium battery electrolyte, papermaking, coatings, elastomers, foam plastics, cosmetics, etc. Polyether is formed by ring-opening polymerization of epoxy monomers, such as epoxy Ethane and propylene oxide are the most commonly used polymerized monomers.

The catalysts most used in the synthesis of polyethers in industry are alkali metal hydroxides or Zn-Co double metal cyanides (DMC). Potassium hydroxide is the most commonly used catalyst because of its low cost and moderate catalytic activity. However, high-quality polyether products cannot be prepared because strong alkalinity easily causes the isomerization reaction of monomers. Moreover, when potassium hydroxide is used as a catalyst, the polyether product needs to be refined to remove potassium ions, which increases the production cost. As a substitute catalyst for potassium hydroxide, double metal cyanide does not require further purification operations during use, has high catalytic activity, and can realize monomer polymerization and conversion into polyether in a short reaction time.

The catalytic activity of double metal cyanide catalysts is mainly affected by the metal active sites, but the metal active sites cannot all participate in the reaction during the reaction process, resulting in low utilization of active metals. By immobilizing the double metal cyanide on the carrier, the researchers successfully increased the activity of the double metal cyanide catalyst while reducing the amount of active metal required. Commonly used carriers are silicon oxide and titanium dioxide. Boron nitride is a crystal composed of nitrogen atoms and boron atoms. It has the advantages of high thermal conductivity, high specific surface area, and strong chemical stability. It can be used as a carrier for ammonia synthesis, CO Catalytic systems such as oxidation and Fischer-Tropsch synthesis.

The present invention adopts boron nitride or modified boron nitride as double metal cyanide catalyst carrier, double metal cyanide as active component, and prepares a kind of high activity catalyst of epoxy ring-opening polymerization and its Preparation method and application.

Contents of the invention

The object of the present invention is to provide a catalyst for epoxy ring-opening polymerization and its preparation method and application. The preparation method of the catalyst for epoxy ring-opening polymerization is simple, double metal cyanide can be uniformly dispersed on the carrier, and the metal active center Availability and quantity are enhanced, increasing its catalytic activity.

To achieve this purpose of the invention, the present invention adopts the following technical solutions:

First aspect, the present invention provides a kind of preparation method of epoxy ring-opening polymerization catalyst, described preparation method comprises the steps:

The carrier, the active component and the solvent are mixed, dried and ground after mixing to obtain the catalyst for epoxy ring-opening polymerization.

The support includes boron nitride and/or modified boron nitride.

Preferably, said mixing comprises sonication and/or stirring.

Preferably, the stirring speed is 300-800r/min, such as 300r/min, 400r/min, 500r/min, 600r/min, 700r/min or 800r/min, but not limited to the listed values, Other unrecited values within the range of values also apply.

Preferably, the stirring time is 12-20h, such as 12h, 13h, 14h, 15h, 16h, 18h or 20h, but not limited to the listed values, and other unlisted values within the numerical range are also applicable.

Preferably, the drying method includes vacuum drying, and the temperature of the vacuum drying is 90-110°C, such as 90°C, 95°C, 100°C, 105°C or 110°C, but not limited to the listed values, Other unrecited values within the range of values also apply.

Preferably, the solvent comprises water.

Preferably, the mass ratio of the carrier, the active component and the solvent is 1:(0.1-0.4):10, such as 1:0.1:10, 1:0.15:10, 1:0.2:10, 1:0.25 :10, 1:0.3:10, 1:0.35:10 or 1:0.4:10, but not limited to the listed values, other unlisted values within the value range are also applicable.

Preferably, the particle size D50 of the catalyst for epoxy ring-opening polymerization obtained after grinding is 0.5-1 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, but not limited to the listed Numerical values, other unrecited numerical values within the numerical range also apply.

Preferably, the preparation method of described boron nitride comprises the following steps:

(1) Mix boric acid, nitrogen source, dispersant and water, dry and crystallize after uniform dispersion, and obtain a crystallization precursor;

(2) pyrolyzing the crystalline precursor obtained in step (1) under a protective atmosphere to obtain the boron nitride;

Preferably, the mass ratio of boric acid, nitrogen source, dispersant and water in step (1) is 1:(20-40):(1-4):(20-50).

The mass ratio of boric acid to nitrogen source in step (1) is 1:(20-40), such as 1:20, 1:25, 1:30, 1:35 or 1:40, but not limited to the listed The numerical value of , other unlisted numerical values in the numerical range are also applicable.

The mass ratio of boric acid to dispersant in step (1) is 1:(1-4), for example, it can be 1:1, 1:2, 1:3 or 1:4, but it is not limited to the listed values, the values Other unrecited values within the range also apply.

The mass ratio of boric acid and water described in step (1) is 1:(20-50), for example can be 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1: 50, but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the nitrogen source in step (1) includes urea and/or melamine.

Preferably, the dispersant in step (1) includes any one or a combination of at least two of PEG-200, PEG-400 or PEG-1000, typical but non-limiting combinations include PEG-200 and PEG-400 A combination of PEG-400 and PEG-1000, a combination of PEG-200 and PEG-1000, or a combination of PEG-200, PEG-400 and PEG-1000.

Preferably, the method for uniform dispersion in step (1) includes ultrasonic dispersion, and the time for ultrasonic dispersion is 5-15 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min , but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the drying temperature in step (1) is 90-100°C, such as 90°C, 92°C, 95°C, 96°C, 98°C or 100°C, but not limited to the listed values, within the range of values Other unlisted values are also applicable; the time is 8-12h, such as 8h, 9h, 10h, 11h or 12h, but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the gas used in the protective atmosphere in step (2) includes nitrogen and/or inert gas.

Preferably, the pyrolysis temperature in step (2) is 900-950°C, for example, it can be 900°C, 910°C, 920°C, 930°C, 940°C or 950°C, but not limited to the listed values, the range of values Other unlisted values are also applicable; the time is 6-9h, such as 6h, 7h, 8h or 9h, but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the preparation method of the modified boron nitride comprises the following steps:

(a) mixing nitrate, boron nitride and water, uniformly dispersing and drying to obtain a precursor;

(b) The precursor obtained in step (a) is pyrolyzed under a protective atmosphere to obtain the modified boron nitride.

After the modified boron nitride is doped with metal, the dispersed metal sites can be used as Lewis acid sites to activate the epoxide, thereby accelerating the ring-opening step.

Preferably, the mass ratio of nitrate, boron nitride and water in step (a) is (0.1-0.5):(1-3):(20-30).

The mass ratio of nitrate to boron nitride in step (a) is (0.1-0.5):(1-3), for example, it can be 0.1:1, 0.3:1, 0.5:1, 0.3:2, 0.5:1 , 0.5:2 or 0.5:3, but not limited to the listed values, other unlisted values within the range of values are also applicable.

The mass ratio of boron nitride to water in step (a) is (1-3):(20-30), for example, it can be 1:20, 1:25, 1:30, 2:20, 2:25, 2:30, 3:20 or 3:25, but not limited to the listed values, other unlisted values within the value range are also applicable.

Preferably, the nitrate in step (a) includes any one or a combination of at least two of lanthanum nitrate, cerium nitrate, zinc nitrate, copper nitrate or cobalt nitrate, typical but non-limiting combinations include lanthanum nitrate and nitrate Combination of cerium, combination of cerium nitrate and zinc nitrate, combination of zinc nitrate and copper nitrate, combination of copper nitrate and cobalt nitrate, combination of lanthanum nitrate, cerium nitrate and zinc nitrate, combination of zinc nitrate, copper nitrate and cobalt nitrate, Or, combinations of lanthanum nitrate, cerium nitrate, zinc nitrate, copper nitrate and copper nitrate.

Preferably, the homogeneous dispersion method in step (a) includes ultrasonic post-stirring.

Preferably, the stirring time is 10-20h, such as 10h, 12h, 15h, 16h, 18h or 20h, but not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the drying temperature in step (a) is 90-100°C, such as 90°C, 92°C, 95°C, 96°C, 98°C or 100°C, but not limited to the listed values, within the range of values Other unlisted values are also applicable; the time is 10-20h, such as 10h, 12h, 15h, 16h, 18h or 20h, but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the gas used in the protective atmosphere in step (b) includes nitrogen and/or inert gas.

Preferably, the pyrolysis temperature in step (b) is 600-700°C, for example, it can be 600°C, 620°C, 640°C, 650°C, 680°C or 700°C, but not limited to the listed values, the range of values Other unlisted values are also applicable; the time is 5-8h, such as 5h, 6h, 7h or 8h, but not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the active ingredient comprises a double metal cyanide.

The double metal cyanide compound of the present invention is a conventional double metal cyanide compound in the field, and the present invention is not specifically limited. Exemplarily, the preparation method of the double metal cyanide compound of the present invention includes the following steps:

(1) mixing zinc acetate dihydrate solution and acetic acid, then the resulting mixed solution is mixed with molecular sieves, heated and stirred to obtain a dispersion;

(II) adding an aqueous solution of potassium cobaltcyanide dropwise to the dispersion liquid obtained in step (I), followed by centrifugation, washing, ultrasonication and drying in sequence to obtain the double metal cyanide.

In a second aspect, the present invention provides a catalyst for epoxy ring-opening polymerization, which is prepared by the preparation method described in the first aspect.

In a third aspect, the present invention provides an application of the catalyst for epoxy ring-opening polymerization described in the second aspect, the catalyst for ring-opening polymerization of epoxy is used for ring-opening polymerization of epoxy compounds;

The epoxy compound includes any one or a combination of at least two of ethylene oxide, propylene oxide or butylene oxide.

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

(1) The present invention can prepare a highly active and stable double metal cyanide catalyst supported by boron nitride or modified boron nitride through a simple impregnation loading method. In catalyzing the polymerization of epoxy compounds, double metal cyanide activity is enhanced by dispersing on the support, and the availability and number of metal active centers are improved;

(2) The boron nitride of the present invention not only has a dispersion effect as a carrier, but the boron atom in the boron nitride has electron-deficient characteristics with Lewis acidity, has the function of activating epoxy monomers, and activates epoxy monomers synergistically with double metal cyanides , to further improve the catalytic activity;

(3) After the boron nitride is modified in the present invention, the Lewis acidity is enhanced, and the effect of synergistically activating the epoxy monomer with double metal cyanide is enhanced, and the catalytic activity is further improved;

(4) The present invention adopts boron nitride or modified supported double metal cyanide, which reduces the consumption of active metal in the catalytic process, and can further reduce the cost of industrial production of polyether.

Detailed ways

The technical solutions of the present invention will be further described below through specific embodiments. It should be clear to those skilled in the art that the examples are only for helping to understand the present invention, and should not be regarded as specific limitations on the present invention.

The double metal cyanide used in the embodiment of the present invention and comparative example adopts following method to prepare, comprises the following steps:

(1) Add zinc acetate dihydrate (3mmol, 657mg) into 15mL deionized water, mix and stir until dissolved, then add 5mL acetic acid and mix well;

(2) Add 2 g of molecular sieves to the solution in step (1), raise the temperature to 80° C., and continue stirring;

(3) Get potassium cobalt cyanide (1.5mmol, 498mg) and be mixed with 10mL aqueous solution, drop in step (2) dispersion liquid with the speed of 5 seconds/drop, take out reaction solution immediately after dropping, with 3500r/min speed Centrifuge for 3 minutes, wash with deionized water three times, each time with 30 mL of water, sonicate for 30 minutes, and vacuum dry at 80°C for 10 hours to obtain 0.62 g of double metal cyanide.

The source of each raw material in the specific embodiment is as follows:

1,2-Butene oxide: CAS number: 106-88-7, after refluxing in calcium hydride for 8 hours, redistilled for use, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

Polyethylene glycol-400 (PEG-400): CAS number; 25322-68-3, molecular weight 400, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

Zinc acetate dihydrate: CAS number; 25322-68-3, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

Potassium cobaltcyanide: CAS number; 13963-58-1, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

Acetic acid: CAS number; 64-19-7, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

PEG-1000: 25322-68-3, average molecular weight 1000, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

The formula for calculating the loading capacity of double metal cyanide is: (total solid mass-boron nitride mass)/total solid mass×100%

Example 1

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

Add 2g of boron nitride and 0.2g of double metal cyanide into 20mL of deionized water, sonicate for 10min, stir at 500r/min for 16h, vacuum dry at 100°C for 10h, and grind to obtain the epoxy ring-opening polymerization with a particle size D50 of 0.8μm. Use a catalyst.

Wherein the preparation method of boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 2

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 1 is that the mass of double metal cyanide in this example is 0.4 g, and the rest are the same as Example 1.

Example 3

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 1 is that the mass of double metal cyanide in this example is 0.5 g, and the rest are the same as Example 1.

Example 4

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 1 is that the mass of double metal cyanide in this example is 0.6 g, and the rest are the same as Example 1.

Example 5

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 1 is that the mass of double metal cyanide in this example is 0.8 g, and the rest are the same as Example 1.

Example 6

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

2g of modified boron nitride and 0.5g of double metal cyanide were added to 20mL of deionized water, ultrasonicated for 10min, stirred at 500r/min for 16h, vacuum-dried at 100°C for 10h, and ground to obtain the epoxy resin with a particle size D50 of 0.8μm. Catalyst for ring polymerization.

The preparation method of the modified boron nitride is as follows: add 0.1g of cerium nitrate and 2g of boron nitride into 20mL of deionized water, sonicate for 10min to obtain a dispersion, stir for 15h, and dry at 100°C for 15h to obtain a precursor. Pyrolyze at 650°C for 6 hours under nitrogen atmosphere, cool to room temperature and grind to obtain the target sample;

The preparation method of used boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 7

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 6 is that the mass of cerium nitrate in this example is 0.3 g, and the rest are the same as Example 6.

Example 8

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 6 is that the mass of cerium nitrate in this example is 0.5 g, and the rest are the same as Example 6.

Example 9

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 6 is that in this example, the quality of cerium nitrate is replaced by copper nitrate, and the rest are the same as in Example 6.

Example 10

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization. The difference from Example 6 is that in this example, the mass of cerium nitrate is replaced by lanthanum nitrate, and the rest are the same as in Example 6.

Example 11

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

Add 2g of boron nitride and 0.2g of double metal cyanide into 20mL of deionized water, sonicate for 10min, stir at 300r/min for 16h, vacuum dry at 100°C for 10h, grind to obtain the catalyst for epoxy ring-opening polymerization with a particle size D50 of 1 μm .

Wherein the preparation method of boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 12

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

Add 2g of boron nitride and 0.2g of double metal cyanide into 20mL of deionized water, sonicate for 10min, stir at 800r/min for 16h, vacuum dry at 100°C for 10h, and grind to obtain a particle size D50 of 0.5μm for epoxy ring-opening polymerization. catalyst.

Wherein the preparation method of boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 13

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

Add 2g of modified boron nitride and 0.5g of double metal cyanide into 20mL of deionized water, ultrasonicate for 10min, stir at 300r/min for 16h, vacuum dry at 100°C for 10h, and grind to obtain the epoxy ring-opened compound with a particle size D50 of 1 μm. Catalyst for polymerization.

The preparation method of the modified boron nitride is as follows: add 0.1g of cerium nitrate and 2g of boron nitride into 20mL of deionized water, sonicate for 10min to obtain a dispersion, stir for 15h, and dry at 100°C for 15h to obtain a precursor. Pyrolyze at 650°C for 6 hours under nitrogen atmosphere, cool to room temperature and grind to obtain the target sample;

The preparation method of used boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 14

The present embodiment provides a kind of preparation method of epoxy ring-opening polymerization catalyst, and described preparation method comprises the steps:

2g of modified boron nitride and 0.5g of double metal cyanide were added to 20mL of deionized water, ultrasonicated for 10min, stirred at 800r/min for 16h, vacuum-dried at 100°C for 10h, and ground to obtain the epoxy resin with a particle size D50 of 0.5μm. Catalyst for ring polymerization.

The preparation method of the modified boron nitride is as follows: add 0.1g of cerium nitrate and 2g of boron nitride into 20mL of deionized water, sonicate for 10min to obtain a dispersion, stir for 15h, and dry at 100°C for 15h to obtain a precursor. Pyrolyze at 650°C for 6 hours under nitrogen atmosphere, cool to room temperature and grind to obtain the target sample;

The preparation method of used boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Example 15

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization, except that the pyrolysis in the preparation of modified boron nitride is carried out at 600° C. for 8 hours under a nitrogen atmosphere, and the rest are the same as in Example 7.

Example 16

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization, except that the pyrolysis in the preparation of modified boron nitride is carried out at 700° C. for 5 hours under a nitrogen atmosphere, and the rest are the same as in Example 7.

Example 17

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization, which is the same as Example 7 except that the pyrolysis temperature is 580° C. when preparing modified boron nitride.

Example 18

This example provides a method for preparing a catalyst for epoxy ring-opening polymerization, which is the same as Example 7 except that the pyrolysis temperature is 720° C. when preparing modified boron nitride.

Comparative example 1

This comparative example provides a kind of double metal cyanide, and preparation method comprises the steps:

(1) Add zinc acetate dihydrate (3mmol, 657mg) into 15mL deionized water, mix and stir until dissolved, then add 5mL acetic acid and mix well;

(2) Add 2 g of molecular sieves to the solution in step (1), raise the temperature to 80° C., and continue stirring;

(3) Get potassium cobalt cyanide (1.5mmol, 498mg) and be mixed with 10mL aqueous solution, drop in step (2) dispersion liquid with the speed of 5 seconds/drop, take out reaction solution immediately after dropping, with 3500r/min speed Centrifuge for 3 minutes, wash with deionized water three times, each time with 30 mL of water, sonicate for 30 minutes, and vacuum dry at 80°C for 10 hours to obtain 0.62 g of double metal cyanide.

Comparative example 2

This comparative example provides a kind of boron nitride, and its preparation method comprises the steps:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Comparative example 3

This comparative example provides a kind of modified boron nitride, and its preparation method comprises the steps:

Add 0.1g of cerium nitrate and 2g of boron nitride into 20mL of deionized water, sonicate for 10min to obtain a dispersion, stir for 15h, and dry at 100°C for 15h to obtain a precursor, pyrolyze the precursor for 6h in a nitrogen atmosphere, cool to room temperature and grind to obtain target sample.

The preparation method of used boron nitride is as follows:

First, 1 g of boric acid, 30 g of urea, and 3 g of PEG-1000 were dissolved in 30 mL of deionized water, and ultrasonicated for 10 min. Then, the solution was poured into a quartz boat and dried at 100 ° C for 10 h to obtain a precursor for crystallization. Finally, the completely recrystallized precursor was pyrolyzed at 950 °C for 6 h under nitrogen atmosphere, cooled to room temperature and ground to obtain the target sample.

Application example 1

The catalysts prepared by Examples 1-18 and Comparative Examples 1-3 are applied in the ring-opening polymerization of epoxy compounds, and the specific operation steps are as follows:

Under the protection of nitrogen, add 1.5mg of catalyst to a 50mL autoclave, then add 5g of polyethylene glycol and 18g of 1,2-butylene oxide, start stirring, raise the temperature to 110°C, react for 6h, cool to room temperature, remove unreacted in vacuo 1,2-epoxybutane, that is, polyether.

The results are shown in Table 1.

Application example 2

Under the protection of nitrogen, add 1.5 mg of the double metal cyanide provided in Comparative Example 1 into a 50 mL autoclave, then add 5 g of polyethylene glycol and 18 g of 1,2-butylene oxide, start stirring, raise the temperature to 110 ° C, and react for 6 h. Cool to room temperature and remove unreacted 1,2-epoxybutane in vacuum to obtain polyether.

Results: The conversion rate of 1,2-butylene oxide was 5.3%.

Application example 3

Under nitrogen protection, add 1.5mg of the double metal cyanide catalyst provided in Comparative Example 1 and the 4.5mg modified boron nitride provided in Example 6 to a 50mL autoclave, then add 5g polyethylene glycol and 18g1,2-epoxy Butane, start stirring, heat up to 110°C, react for 6h, cool to room temperature, remove unreacted 1,2-epoxybutane in vacuum to obtain polyether.

Results: The conversion rate of 1,2-butylene oxide was 45.6%.

Table 1

Catalyzed ring-opening polymerization of epoxide by embodiment 3 and comparative example 1, embodiment 3 is boron nitride supported double metal cyanide catalyst catalyzed ring-opening polymerization of 1,2-epoxybutane, reaction 6h, 1,2- The conversion rate of butylene oxide is as high as 91.1%, while the double metal cyanide catalyst in comparative example 1 catalyzes the ring-opening polymerization of 1,2-butylene oxide, and the conversion rate of 1,2-butylene oxide is 25.1% after 6 hours of reaction . The results show that boron nitride and double metal cyanide catalysts have a synergistic catalytic effect and can increase the rate of ring-opening polymerization of 1,2-butylene oxide. In Example 7, after boron nitride is modified, double metal cyanide is supported as a catalyst, and the 6h conversion rate of 1,2-epoxybutylene is as high as 99.8%, which shows that after the modified boron nitride anchors the metal site, The Lewis acidity is enhanced, and the catalytic activity is enhanced.

Comparing Example 7 with Application Example 3, it can be found that the catalytic activity of double metal cyanide supported on modified boron nitride is significantly higher than that of the mixture of double metal cyanide and modified boron nitride. It shows that when the distance between the zinc site of DMC and the Lewis site on the surface of boron nitride is very close, the synergistic catalytic effect can be better produced. When boron nitride or modified boron nitride is used as a catalyst alone, it is difficult to realize the ring opening of epoxy compounds only by the Lewis acid sites of boron and metal, so there is no catalytic activity.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any person skilled in the art is within the technical scope disclosed in the present invention. Easily conceivable changes or substitutions all fall within the scope of protection and disclosure of the present invention.

Claims (23)

1. A method for preparing a catalyst for ring-opening polymerization of epoxy, which is characterized by comprising the following steps:

mixing a carrier, an active component and a solvent, drying after mixing, and grinding to obtain the catalyst for epoxy ring-opening polymerization;

the carrier is modified boron nitride;

the active component is double metal cyanide;

the preparation method of the modified boron nitride comprises the following steps:

(a) Mixing nitrate, boron nitride and water, uniformly dispersing and drying to obtain a precursor; the nitrate comprises any one or a combination of at least two of lanthanum nitrate, cerium nitrate, zinc nitrate, copper nitrate and cobalt nitrate;

(b) Pyrolyzing the precursor obtained in the step (a) in a protective atmosphere to obtain the modified boron nitride;

the preparation method of the boron nitride comprises the following steps:

(1) Mixing boric acid, a nitrogen source, a dispersing agent and water, uniformly dispersing, drying and crystallizing to obtain a crystallization precursor;

(2) Pyrolyzing the crystal precursor obtained in the step (1) in a protective atmosphere to obtain the boron nitride.

2. The method of preparation according to claim 1, wherein the mixing comprises ultrasound and/or stirring.

3. The method according to claim 2, wherein the stirring speed is 300-800r/min.

4. The method of claim 2, wherein the stirring is for a period of 12-20 hours.

5. The method according to claim 2, wherein in the drying after mixing, the drying method comprises vacuum drying at a temperature of 90 to 110 ℃.

6. The method of claim 1, wherein the solvent comprises water.

7. The preparation method according to claim 1, wherein the mass ratio of the carrier, the active ingredient and the solvent is 1 (0.1-0.4): 10.

8. The process according to claim 1, wherein the particle diameter D50 of the catalyst for ring-opening polymerization obtained after grinding is 0.5 to 1. Mu.m.

9. The preparation method according to claim 1, wherein the mass ratio of boric acid, nitrogen source, dispersant and water in the step (1) is 1 (20-40): 1-4): 20-50.

10. The method of claim 1, wherein the nitrogen source of step (1) comprises urea and/or melamine.

11. The method of claim 1, wherein the dispersant of step (1) comprises any one or a combination of at least two of PEG-200, PEG-400, or PEG-1000.

12. The method of claim 1, wherein the method of uniform dispersion in step (1) comprises ultrasonic dispersion for a period of 5 to 15 minutes.

13. The method according to claim 1, wherein the drying in step (1) is carried out at a temperature of 90 to 100 ℃ for a time of 8 to 12 hours.

14. The method according to claim 1, wherein the gas used in the protective atmosphere in the step (2) comprises nitrogen and/or inert gas.

15. The method of claim 1, wherein the pyrolysis in step (2) is performed at a temperature of 900 to 950 ℃ for a period of 6 to 9 hours.

16. The method according to claim 1, wherein the mass ratio of the nitrate, boron nitride and water in the step (a) is (0.1-0.5): 1-3): 20-30.

17. The method of claim 1, wherein the method of uniform dispersion of step (a) comprises post-ultrasonic agitation.

18. The method of claim 17, wherein the stirring is for a period of 10 to 20 hours.

19. The method of claim 1, wherein the drying in step (a) is performed at a temperature of 90-100 ℃ for a time of 10-20 hours.

20. The method according to claim 1, wherein the gas used in the protective atmosphere in the step (b) comprises nitrogen and/or inert gas.

21. The method of claim 1, wherein the pyrolysis in step (b) is performed at a temperature of 600-700 ℃ for a period of 5-8 hours.

22. A catalyst for ring-opening polymerization of epoxy, characterized in that it is prepared by the preparation method according to any one of claims 1 to 21.

23. The use of the catalyst for ring-opening polymerization of epoxy according to claim 22, wherein the catalyst for ring-opening polymerization of epoxy compound is used for ring-opening polymerization of epoxy compound;

the epoxy compound includes any one or a combination of at least two of ethylene oxide, propylene oxide, or butylene oxide.