A boron / ammonium salt non-metallic catalyst, its preparation method and application

Abstract

The application relates to the field of high polymer materials, in particular to a boron / ammonium salt type nonmetallic catalyst and a preparation method and application thereof. The boron / ammonium salt type nonmetallic catalyst integrates an organic boron Lewis acid and an ammonium salt together, so that the nonmetallic catalyst has high selectivity and reaction activity, is low in water sensitivity, has a mild reaction condition in a reaction process of catalytic synthesis of carbon dioxide-based polycarbonate, does not need an additional catalytic material, and has high molecular weight and narrow molecular distribution of the prepared carbon dioxide-based polycarbonate. Furthermore, the nonmetallic catalyst further comprises an aromatic structural unit connected with a carboxylic acid phosphonium salt, the carboxylic acid phosphonium salt reduces the water sensitivity of the catalyst and a carbon dioxide-based polycarbonate synthesis reaction system, further improves the molecular weight of the prepared carbon dioxide-based polycarbonate, and reduces the molecular distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer materials, in particular to a boron / ammonium salt non-metallic catalyst and a preparation method and application thereof. BACKGROUND

[0002] The rapid development of the global economy has brought about climate warming, which has become a major environmental problem. The massive emission of greenhouse gases, mainly CO2, has led to the intensification of climate warming in recent years. From the perspective of resource utilization, CO2, as a cheap, non-toxic and abundant resource, can be converted into various high-value organic chemicals. At the same time, in order to limit and reduce the use of plastic bags and curb the "white pollution", polycarbonates can be synthesized by the reaction of CO2 and epoxide compounds, which can consume CO2 and obtain completely biodegradable green carbon materials.

[0003] However, due to the high activation energy of the reaction, most of the catalysts used in the current reaction system are metal-based catalysts (such as zinc glutarate and rare earth catalysts), which have the technical bottlenecks of harsh reaction conditions (high temperature (≥100℃), high pressure (≥2MPa) and long reaction time (40 hours)), poor water tolerance, high cost, and high metal residue in the product, complicated separation and recovery, etc. Therefore, it is a key and core problem to develop a cheap and easily available non-metallic catalyst with high catalytic activity and strong stability to realize the efficient conversion of CO2 / epoxide compounds under mild conditions. SUMMARY

[0004] In order to solve the problem that most of the current polycarbonate reaction systems use metal-based catalysts, which have harsh reaction conditions and poor water tolerance, the present application provides a boron / ammonium salt non-metallic catalyst and a preparation method and application thereof.

[0005] In a first aspect, the present application provides a boron / ammonium salt non-metallic catalyst:

[0006] A boron / ammonium salt non-metallic catalyst, which has the following structure:

[0007]

[0008] Wherein, R is -CH3 or -CF3, and M is phenyl or naphthyl.

[0009] By using the above technical solution, an organic boron-ammonium salt functionalized catalyst is constructed, which utilizes the synergistic catalytic effect of organic boron Lewis acid and ammonium salt to make the non-metallic catalyst have high selectivity and reaction activity, and the reaction process of catalytic synthesis of carbon dioxide-based polycarbonates has mild reaction conditions without the need for additional catalytic materials.

[0010] The non-metallic catalyst also comprises a phenyl or naphthyl aromatic structural unit connected with a carboxylic acid phosphonium salt which can be hydrolyzed in water, thereby reducing the sensitivity of the catalyst to water and the influence of water on the synthesis of the carbon dioxide-based polycarbonate, i.e., the molecular weight of the carbon dioxide-based polycarbonate is low and the molecular distribution is wide. Therefore, the reaction conditions for preparing the carbon dioxide-based polycarbonate by using the non-metallic catalyst are relatively mild, the influence of water on the reaction system is small, the molecular weight of the prepared carbon dioxide-based polycarbonate is high, and the molecular distribution is narrow, which is of great significance for realizing efficient conversion of CO2 / epoxide under mild conditions.

[0011] In a second aspect, the application provides a preparation method of a boron / ammonium salt-based non-metallic catalyst.

[0012] The preparation method of the boron / ammonium salt-based non-metallic catalyst comprises the following steps:

[0013] Preparation of compound I: 1 mol of triphenylphosphine is dissolved in acetonitrile, 0.8-1.5 mol of a dihalo aromatic hydrocarbon compound is added under inert gas protection, and heating is performed at 60-80°C for 20-48 h. After precipitation, filtration, washing and drying, compound I is prepared.

[0014] Preparation of compound II: 0.8 mol of compound I, 0.8-1.5 mol of a carboxylic acid salt and an organic solvent are mixed, and stirring is performed at 20-40°C for 30-50 h. After filtration, washing and drying, compound II is prepared.

[0015] Preparation of compound III: 0.5-1 mol of a polyallylamine, 0.5 mol of compound II and 1 mol of potassium carbonate are dissolved in an organic solvent under inert gas protection, and refluxing is performed at 80-150°C for 10-24 h. After quenching, separation, purification and drying, compound III is prepared.

[0016] Preparation of the non-metallic catalyst: 0.3-0.5 mol of 9-borabicyclo[3.3.1]nonane and 0.3 mol of compound III are dissolved in an organic solvent solution under inert gas protection, and reaction is performed at 40-80°C for 5-24 h. After concentration, purification and drying, compound IV, i.e., the non-metallic catalyst, is prepared.

[0017] By using the above technical solution, the boron / ammonium salt-based non-metallic catalyst with high reaction activity, high selectivity and low sensitivity to water is prepared.

[0018] The carboxylate salt is replaced by compound I during the reaction, and then a polyallylamine is used for amination, so that the ammonium salt in the prepared non-metallic catalyst is more likely to coordinate and open the ring function, so that the prepared non-metallic catalyst has low water sensitivity and high reaction activity.

[0019] Preferably, in the preparation of compound II, the molar ratio of triphenylphosphine to dihalogen aromatic compound is 1:(1-1.2).

[0020] By controlling the molar ratio of triphenylphosphine to dihalogen aromatic compound, the triphenylphosphine reacts well with one halogen in the dihalogen aromatic compound, the carboxylate phosphonium salt is connected in the non-metallic catalyst, and the water sensitivity of the non-metallic catalyst and the system using the non-metallic catalyst for synthesizing carbon dioxide-based polycarbonate is reduced, and the carbon dioxide-based polycarbonate prepared by using the catalyst has high molecular weight and narrow molecular distribution.

[0021] Preferably, the organic solvent is one of tetrahydrofuran, chloroform, and acetonitrile.

[0022] Preferably, the polyallylamine is one of triallylamine and diallylamine.

[0023] Preferably, the dihalogen aromatic compound is dibromobenzene or dibromonaphthalene.

[0024] Preferably, the carboxylate salt is sodium acetate or sodium trifluoroacetate.

[0025] By using the above technical solution, a boron / ammonium salt non-metallic catalyst with high reaction activity, high selectivity and low water sensitivity is prepared.

[0026] In a third aspect, the application provides an application of a boron / ammonium salt non-metallic catalyst:

[0027] The application of a boron / ammonium salt non-metallic catalyst is used for synthesizing carbon dioxide-based polycarbonate, and the molecular weight of the carbon dioxide-based polycarbonate is 32000-1000000g / mol, and the molecular weight distribution is 1.05-2.50.

[0028] Preferably, the reaction temperature in the synthesis of the carbon dioxide-based polycarbonate is 50-80℃, and the reaction time is 12-48h.

[0029] By using the above technical solution, by using the non-metallic catalyst in the synthesis of carbon dioxide-based polycarbonate, the reaction conditions are mild, the water sensitivity is low, and the carbon dioxide-based polycarbonate prepared by using the catalyst has high molecular weight and narrow molecular weight distribution.

[0030] In summary, the present application has the following advantages:

[0031] 1. A boron / ammonium salt non-metallic catalyst, the integration of organic boron Lewis acid and ammonium salt together, makes the non-metallic catalyst have higher selectivity and reaction activity, lower sensitivity to water, and the reaction condition of the catalytic synthesis of carbon dioxide-based polycarbonate is mild, without additional catalytic material, and the prepared carbon dioxide-based polycarbonate has higher molecular weight and narrower molecular distribution.

[0032] 2. Further, the structure of the prepared non-metallic catalyst also contains aromatic structural units connected with carboxylic acid phosphonium salt, which reduces the sensitivity of the catalyst and the synthesis of carbon dioxide-based polycarbonate reaction system to water, further improves the molecular weight of the prepared carbon dioxide-based polycarbonate, and reduces the molecular distribution.

[0033] 3. Preferably, the non-metallic catalyst is prepared by replacing the carboxylate of compound I and then aminating with polyallylamine, and the prepared non-metallic catalyst has higher reaction activity and better water resistance. DETAILED DESCRIPTION

[0034] EMBODIMENT

[0035] Example 1, a boron / ammonium salt non-metallic catalyst, using raw materials as shown in Table 1, the chemical reaction process is as follows:

[0036]

[0037] The specific preparation process is as follows, using raw materials as shown in Table 1:

[0038] Preparation of compound I: In a glove box, dissolve triphenylphosphine in an organic solvent acetonitrile and add to a Schlenk flask, add dihalogen aromatic hydrocarbon compound (use p-dibromobenzene) to the Schlenk flask under nitrogen protection, and heat at 70°C for 30h. Concentrate the reaction mixture to half under vacuum, add three times the original volume of diethyl ether, and put it in a refrigerator at-30°C overnight. After the precipitate is separated out, quickly filter the precipitate and wash with cold diethyl ether three times, dry the washed product to obtain compound I; and vacuum dry at 40°C for 12h, the isolated yield is 93.5%.

[0039] Preparation of compound II: In a glove box, compound I and carboxylate (use sodium acetate) are loaded into a 10ml Schlenk flask, add organic solvent acetonitrile and stir the reaction mixture at 30°C for 40h, filter, wash with cold diethyl ether three times, vacuum dry at 40°C for 12h, and obtain compound II with a yield of 93.4%.

[0040] Preparation of compound III: In a glove box, compound II, polyallylamine (diallylamine was used), and acetonitrile were loaded into a polytetrafluoroethylene valve-sealed Schlenk flask, which was heated at 100°C for 20 h, and then quenched with water. The organic phase was separated, and the aqueous phase was extracted with an organic solvent. The solvent was removed under reduced pressure to obtain a crude product, which was purified by column chromatography and dried to obtain compound III.

[0041] Preparation of compound IV / non-metallic catalyst: In a glove box, 9-borabicyclo[3.3.1]nonane, compound III, and acetonitrile were mixed in a Schlenk flask, which was then reacted at 50°C for 15 h. The reaction mixture was concentrated under vacuum to obtain a crude solid product, which was further purified by washing with n-hexane three times and dried under vacuum at 40°C for 12 h to obtain compound IV, i.e., the non-metallic catalyst, with a separation yield of 93.6%.

[0042] Examples 2 to 3, a boron / ammonium salt non-metallic catalyst, which differs from Example 1 in that different raw materials and process parameters are used, as shown in Table 1.

[0043] Table 1: List of raw materials and process parameters used in the preparation of the boron / ammonium salt non-metallic catalysts of Examples 1 to 3

[0044]

[0045]

[0046]

[0047] The yield is the ratio of the actual mass obtained to the theoretical mass obtained.

[0048] Example 4, a boron / ammonium salt non-metallic catalyst, which differs from Example 1 in that triallylamine is used instead of diallylamine.

[0049] Example 5, a boron / ammonium salt non-metallic catalyst, which differs from Example 1 in that allylamine is used instead of diallylamine.

[0050] Example 6, a boron / ammonium salt non-metallic catalyst, which differs from Example 1 in that the molar ratio of triphenylphosphine to dihaloaromatic compound in the preparation of compound I is 1:1.2.

[0051] Example 7, a boron / ammonium salt non-metallic catalyst, which differs from Example 1 in that the molar ratio of triphenylphosphine to dihaloaromatic compound in the preparation of compound I is 1:0.8.

[0052] Example 8, a boron / ammonium salt-based non-metallic catalyst, differs from Example 1 in that the molar ratio of triphenylphosphine to dihaloaromatic compound in the preparation of compound I is 1:1.5.

[0053] Table 2: Yields of each step in the preparation process of the boron / ammonium salt-based non-metallic catalysts of Examples 6 to 8 and Example 1

[0054] Application Example 1, application of a boron / ammonium salt-based non-metallic catalyst, for the synthesis of carbon dioxide-based polycarbonates, the preparation process of the carbon dioxide-based polycarbonates being as follows:

[0055] Into a 10 mL high-pressure reactor, 0.01 g of the non-metallic catalyst of Example 1, 0.116 g of propylene oxide and 0.0005 g of water (to simulate the effect of incomplete removal of water from the raw materials on polyester synthesis) were sequentially added, and the temperature was raised to 50°C. CO2was then charged to a reaction pressure of 1 MPa, and the reaction was allowed to proceed for 24 h. After cooling to room temperature, the resulting product was washed with chloroform, and the catalyst was obtained by centrifugation. The supernatant was dried by rotary evaporation to obtain polycarbonate.

[0056] Application Example 2, application of a boron / ammonium salt-based non-metallic catalyst, differs from Application Example 1 in that the non-metallic catalyst of Example 2 is used, and the reaction temperature is 60°C, and the reaction time is 12 h.

[0057] Application Example 3, application of a boron / ammonium salt-based non-metallic catalyst, differs from Application Example 1 in that the non-metallic catalyst of Example 3 is used, and the reaction temperature is 80°C, and the reaction time is 48 h.

[0058] Application Examples 4 to 8, application of a boron / ammonium salt-based non-metallic catalyst, differ from Application Example 1 in that the non-metallic catalysts of Examples 4 to 8 are used, respectively.

[0059] Comparative Example

[0060] Comparative Example 1, a boron / ammonium salt-based non-metallic catalyst, differs from Example 1 in that compound I is not reacted with a carboxylate salt (i.e., compound II is not prepared), and compound III is prepared using an equimolar amount of compound I instead of compound II.

[0061] Comparative Example 2, a boron / ammonium salt-based non-metallic catalyst, differs from Example 1 in that compound I is not reacted with a carboxylate salt (i.e., compound II is not prepared), and compound III is prepared using an equimolar amount of compound I instead of compound II; 0.2 mmol of compound IV and 0.2 mmol of sodium acetate are added to 6 mL of acetonitrile, and the reaction mixture is stirred at 100°C for 20 h. After filtration, washing with cold diethyl ether three times, and drying under vacuum at 40°C for 12 h, a non-metallic catalyst is prepared.

[0062] Comparative Example 3, application of a boron / ammonium salt type non-metallic catalyst, differs from Comparative Example 1 in that the non-metallic catalyst is replaced by the non-metallic catalyst of Comparative Example 2.

[0063] Comparative Example 3, application of a boron / ammonium salt type non-metallic catalyst, differs from Comparative Example 1 in that the non-metallic catalyst is replaced by the non-metallic catalyst of Comparative Example 2.

[0064] Performance test

[0065] Test 1: yield

[0066] The yield is the ratio of the actual mass obtained to the theoretical mass obtained, and the calculation results are shown in Table 3.

[0067] Test 2: molecular weight and molecular weight distribution

[0068] The gel chromatography method is used to test the molecular weight and molecular weight distribution of the polycarbonates prepared in Application Examples 1 to 8 and Comparative Examples 1 to 3, and the test results are shown in Table 3.

[0069] Table 3: list of molecular weight, molecular weight distribution and yield of polycarbonates prepared in Application Examples 1 to 8 and Comparative Examples 1 to 3

[0070]

[0071]

[0072] In combination with Application Examples 1 to 8 and Comparative Examples 1 to 3 and in combination with Table 3, it can be seen that:

[0073] Compared with Comparative Examples 1 to 2, the yield and number average molecular weight of the polycarbonate prepared by using Application Example 1 are higher, and the molecular weight distribution is narrower; it is shown that in the preparation of the non-metallic catalyst, after the carboxylate displacement of the compound I is carried out, then the amination is carried out by using the polyallylamine, the prepared non-metallic catalyst has higher reaction activity and better water resistance; it is possible that the carboxylate displacement of the compound I is carried out, so that the non-metallic catalyst is connected with the triphenylphosphine carboxylate, and the triphenylphosphine carboxylate can be hydrolyzed to consume water in the presence of water, thereby reducing the influence of water on the boron element in the non-metallic catalyst and on the polyester synthesis system, so that even in the presence of a small amount of water, the polycarbonate with higher yield and number average molecular weight and narrower molecular weight distribution can still be prepared.

[0074] Compared with the application example 2, the last step is used to replace the carboxylate salt, which may cause the replacement of the anion in the ammonium salt in the non-metallic catalyst by part of the carboxylate salt, resulting in the decrease of the activity of the non-metallic catalyst, and then resulting in the decrease of the yield and the number average molecular weight of the polycarbonate prepared.

[0075] Compared with the application example 1, the number average molecular weight of the polycarbonate prepared in the comparative application example 3 is lower, and the molecular weight distribution is wider, which may be because compared with p-dibromobenzene, dibromopentane has no aromaticity and poor stability, and the activity of the triphenylphosphine carboxylate connected on the dibromopentane is higher, which has a certain catalytic effect on the synthesis of polycarbonate, resulting in the poor selectivity of the non-metallic catalyst prepared to the ring-opening polymerization of propylene oxide, and then resulting in the decrease of the number average molecular weight of the polycarbonate prepared and the widening of the molecular weight distribution.

[0076] Compared with the application example 5 (allyl amine is used in the non-metallic catalyst), the yield and the number average molecular weight of the polycarbonate prepared in the application examples 1 and 4 (diallylamine and triallylamine are used in the non-metallic catalyst in turn) are higher, and the molecular weight distribution is narrower; it may be because the diallylamine or triallylamine is used in the non-metallic catalyst, so that the nitrogen element in the ammonium salt in the non-metallic catalyst is connected with more boron Lewis acid, and the ammonium salt in the non-metallic catalyst has better coordination selectivity and reactivity with the boron Lewis acid, so that the yield and the number average molecular weight of the polycarbonate prepared by using the non-metallic catalyst are higher, and the molecular weight distribution is narrower.

[0077] Compared with the non-metallic catalysts of the embodiments 8 and 7, the number average molecular weight of the polycarbonate prepared by using the non-metallic catalysts of the embodiments 1 and 6 in the application examples 1 and 6 is higher, and the molecular weight distribution is narrower, which indicates that in the preparation of the compound II of the non-metallic catalyst, the molar ratio of triphenylphosphine to the dihalogen aromatic hydrocarbon compound is 1: (1-1.2), and the yield and the number average molecular weight of the polycarbonate prepared by using the non-metallic catalyst are higher, and the molecular weight distribution is narrower, which may be because a relatively small amount of triphenylphosphine is used in the embodiment 8, resulting in that part of the non-metallic catalyst is not connected with the triphenylphosphine group, and then the triphenylphosphine carboxylate is not formed, resulting in that the non-metallic catalyst prepared is sensitive to water, and water as a chain transfer agent, resulting in that the number average molecular weight of the polycarbonate prepared in the application example 8 is lower, and the molecular weight distribution is wider.

[0078] It may be because a relatively large amount of triphenylphosphine is used in the embodiment 7, so that the two bromine elements in part of the p-dibromobenzene react with the triphenylphosphine, resulting in that part of the non-metallic catalyst is not connected with the dihalogen aromatic hydrocarbon compound, and the triphenylphosphine carboxylate is not formed, resulting in that the non-metallic catalyst prepared is sensitive to water, and water as a chain transfer agent, resulting in that the yield and the number average molecular weight of the polycarbonate prepared by using the application example 7 are lower, and the molecular weight distribution is wider.

[0079] The embodiments are only illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments according to the present application without creative contribution, as long as the modifications are within the scope of the claims of the present application.

Claims

1. A boron / ammonium salt non-metallic catalyst having the following structure: in, R is -CH3 or -CF3, and M is phenylene or naphthylene.

2. A method for preparing the boron / ammonium salt non-metallic catalyst according to claim 1, wherein the preparation process is as follows: Preparation of Compound I: Dissolve 1 mol of triphenylphosphine in acetonitrile, add 0.8-1.5 mol of a dihalogen aromatic compound under inert gas protection, and heat at 60-80°C for 20-48 hours. Precipitate, filter, wash, and dry to obtain Compound I. Preparation of compound II: 0.8 mol of compound I, 0.8-1.5 mol of carboxylate and an organic solvent are mixed, stirred at 20-40°C for 30-50h, filtered, washed and dried to obtain compound II; Preparation of compound III: Under inert gas protection, 0.5-1 mol of polyallylamine, 0.5 mol of compound II and 1 mol of potassium carbonate are dissolved in an organic solvent, followed by reflux reaction at 80-150°C for 10-24 hours, quenching the reaction, and then separating, purifying and drying to obtain compound III; Preparation of the non-metallic catalyst: Under inert gas protection, 0.3-0.5 mol of 9-borabicyclo[3.3.1]nonane and 0.3 mol of compound III are dissolved in an organic solvent solution, followed by reaction at 40-80°C for 5-24 hours. After concentration, purification, and drying, compound IV is prepared, which is the non-metallic catalyst. The polyallylamine is one of triallylamine and diallylamine; The dihalogenated aromatic compound is dibromobenzene or dibromonaphthalene; The carboxylate is sodium acetate or sodium trifluoroacetate.

3. The method for preparing the boron / ammonium salt non-metallic catalyst according to claim 2, wherein: In the preparation of the compound II, the molar ratio of triphenylphosphine to the dihalogen aromatic compound is 1:(1-1.2).

4. The method for preparing the boron / ammonium salt non-metallic catalyst according to claim 2, wherein: The organic solvent is one of tetrahydrofuran, chloroform and acetonitrile.

5. Use of the boron / ammonium salt non-metallic catalyst according to claim 1, characterized in that: The invention is used for synthesizing carbon dioxide-based polycarbonate, wherein the molecular weight of the carbon dioxide-based polycarbonate is 11,000-1,000,000 g / mol and the molecular weight distribution is 1.05-2.

50.

6. The use of the boron / ammonium salt non-metallic catalyst according to claim 5, characterized in that: During the synthesis of the carbon dioxide-based polycarbonate, the reaction temperature is 50-80° C. and the reaction time is 12-48 hours.

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