Process for the co-production of dmaeem and dmdee and use of dmaeem

Abstract

The application belongs to the field of organic synthesis and particularly relates to a method for co-producing dimethylaminoethoxyethyl morpholine (DMAEEM) and bis(morpholinoethyl) ether (DMDEE) by using diethylene glycol and morpholine as raw materials, aminating with a catalytic amination agent, and preparing DMAEEM in one pot and co-producing DMDEE. The method for preparing DMAEEM and co-producing DMDEE has high product selectivity and simple separation. The application also provides a method for preparing polyurethane foam by using the prepared DMAEEM, and the obtained polyurethane foam still has high foaming activity at low temperature and is high in economy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic synthesis, and particularly relates to a method for co-production of dimethylaminoethoxyethyl morpholine (DMAEEM) and bis(morpholinoethyl) ether (DMDEE). BACKGROUND

[0002] DMDEE (bis(morpholinoethyl) ether) has a CAS number of 6425-39-4, a molecular formula of C 12 H 24 N2O2, a molecular weight of 244.0, and a structural formula as shown in Formula 1 below. It is an amine catalyst suitable for one-component water-curing systems. It is a strong foaming catalyst, and due to the steric effect of the amino group, it can provide a long storage period for the NCO-containing component. It is mainly used in one-component rigid polyurethane foam systems, and can also be used in polyether and polyester polyurethane soft foam, semi-rigid foam, CASE materials, etc.

[0003]

[0004] Structural formula of DMDEE

[0005] DMAEEM (dimethylaminoethoxyethyl morpholine) has a CAS number of 99178-63-9, a molecular formula of C 10 H 22 N2O2, a molecular weight of 202.29, and a structural formula as shown in Formula 2 below. Although there are reports on the preparation method of DMAEEM, there is no report on its main use.

[0006]

[0007] Structural formula of DMAEEM

[0008] The current literature on the preparation method of DMAEEM is as follows:

[0009] Patent US20090216015A1 discloses a method for synthesizing DMAEEM from N,N-dimethylethanolamine and N-(2-chloroethyl) morpholine hydrochloride. N,N-dimethylethanolamine is dissolved in a solvent tetrahydrofuran, sodium hydride (60% dispersed in oil) is added, heated at 60°C for 1h, then cooled to room temperature, followed by adding N-(2-chloroethyl) morpholine hydrochloride in batches, stirring at 25°C for 18h, and then extracting, drying and distilling to obtain DMAEEM. The method has relatively low atom economy, and involves the generation of halogen-containing, salt and other by-products in the reaction process, which is not friendly to the environment.

[0010] A method for synthesizing DMAEEM by transesterification is reported in document (Ziwei Li, Zeng Hong, Chao Qian, et al. Chemistry: A European journal, 2024, 30(10)), which proposes two similar process routes: a) after N,N-dimethylethanolamine reacts with sulfuric acid to form the corresponding sulfate, the target product is generated by transesterification reaction with morpholine ethanol at 110°C under the catalysis of KOH, with a yield of 74%; b) after morpholine ethanol reacts with sulfuric acid to form the corresponding sulfate, the target product is generated by transesterification reaction with N,N-dimethylethanolamine at 110°C under the catalysis of KOH, with a yield of 81%. The transesterification method is simple and has mild reaction conditions, but an equivalent amount of by-product sulfate is generated during the reaction process, and the treatment of three wastes is difficult. SUMMARY

[0011] The technical problem to be solved by the present application is to provide a method for co-producing DMAEEM and DMDEE and the use of DMAEEM.

[0012] In order to solve the above technical problems, the present application provides a method for co-producing DMAEEM and DMDEE, comprising the following steps:

[0013] 1) Put diethylene glycol and morpholine into an autoclave, and add an amination catalyst into the autoclave. After gas replacement in the autoclave with an inert gas, hydrogen is introduced into the autoclave until the pressure is 1.0-3.0 MPa (preferably 1-2 MPa), and then the temperature is raised to 200-250°C. The reaction is carried out at a pressure of 2.8-8.0 MPa (preferably 2.8-6.5 MPa) for 5-25 h to obtain reaction liquid I, which contains DMDEE and 2-(2-morpholinoethoxy) ethanol;

[0014] Note: During the reaction, light components are generated, so the pressure will increase as the reaction proceeds;

[0015] 2) Cool the reaction liquid I obtained in step 1) to 170-220°C (preferably 180-200°C), and intermittently pump dimethylamine (using a plunger pump) into the autoclave. After the completion of dimethylamine pumping, the reaction is carried out at a set reaction pressure at 170-220°C for 5-30 h (preferably 180-200°C for 6-30 h) to obtain reaction liquid II, which contains DMAEEM and DMDEE;

[0016] The set reaction pressure is 2.0-8.0 MPa (preferably 4.0-5.5 MPa, for example 4.5 MPa);

[0017] Dipropylene glycol: morpholine: dimethylamine = 1: (1.5-5.0): (0.5-2.0) molar ratio; the amount of amine catalyst added is 1%-40% of the mass of dipropylene glycol;

[0018] Description: The reaction process of the present application is one-pot synthesis of DMAEEM and DMDEE in a high-pressure reaction kettle;

[0019] 3) After step 2) is completed, the obtained reaction solution II is cooled to 60±10℃, and then the gas is discharged through the gas discharge valve of the high-pressure kettle (i.e., the unreacted dimethylamine is slowly discharged);

[0020] Then continue to cool to room temperature, open the kettle and stand (usually for 3-5h), filter the obtained standing product, and distill the filtrate (distill under reduced pressure) to obtain morpholine (recovered and used), DMAEEM (as a product) and DMDEE (as a product), respectively.

[0021] Description: Distill the filtrate, collect the morpholine fraction at about 50℃ under water pump-0.1MPa, collect the DMAEEM fraction at about 120℃ under oil pump 300Pa under reduced pressure, and collect the DMDEE fraction at about 155℃ under oil pump 300Pa under reduced pressure.

[0022] Improvement of the method for co-producing DMDEE with DMAEEM of the present application: the amine catalyst is any one of Raney Cu, Raney Ni, and metal amine catalyst.

[0023] Further improvement of the method for co-producing DMDEE with DMAEEM of the present application: the intermittent pumping of dimethylamine in step 2) is as follows: when the pressure rises more than 0.5MPa above the set pressure, stop pumping dimethylamine; otherwise, when the pressure drops to 0.5-1.0MPa below the set pressure, continue pumping dimethylamine.

[0024] Description: Dimethylamine is a gas, which is used as a raw material for the continuous reaction with the intermediate to generate DMAEEM. Dimethylamine needs to be intermittently pumped under high temperature and high pressure. The pressure will rise as dimethylamine enters, and will drop after dimethylamine is consumed. That is, intermittent pumping of dimethylamine can avoid the phenomenon of sudden pressure rise caused by one-time pumping of too much dimethylamine.

[0025] The time for intermittent pumping of dimethylamine is about 8-12h.

[0026] Further improvement of the method for co-producing DMDEE with DMAEEM of the present application: the dimethylamine discharged by the gas discharge valve is absorbed with water to obtain a dimethylamine aqueous solution;

[0027] The morpholine recovered by distillation in step 3) can be used for the next batch of reaction;

[0028] The step 3) filters the obtained filter cake after water washing, and the amine catalyst can be used for the next batch reaction.

[0029] Description: Because the amount of catalyst is lost in the recovery process, when the catalyst is used, new catalyst needs to be supplemented to the set amount (the supplement amount is about 5% to 10% of the set amount).

[0030] Further improvement of the method for co-producing DMAEEM and DMDEE according to the present application:

[0031] The molar ratio of diethylene glycol: morpholine: dimethylamine is 1:2.9-3.1:0.7-0.8 (preferably 1:3:0.75);

[0032] The amine catalyst is 10% to 15% of the mass of diethylene glycol.

[0033] Further improvement of the method for co-producing DMAEEM and DMDEE according to the present application, the preparation method of the metal amine catalyst is:

[0034] According to the set mass ratio of metal, add metal nitrate providing active components and alumina as carrier to the reaction kettle, and add deionized water, stir and soak at 50±10℃ for 6±1h, then dry the water (dry the water in a 120±10℃ oven), grind the obtained solid into powder, and then perform programmed temperature roasting (place in a muffle furnace), the programmed temperature is: from room temperature to 200±20℃, heat roasting for 0.5±0.1h; then heat to 300±20℃, heat roasting for 0.5±0.1h; then heat to 400±20℃, heat roasting for 1±0.1h; then heat to 500±20℃, heat roasting for 4±0.1h, to obtain the metal amine catalyst;

[0035] The active components are at least two of Cu, Ni, Co and Zr, and correspondingly, the metal nitrate is selected from at least two of Cu(NO3)2, Ni(NO3)2, Co(NO3)2 and Zr(NO3)4;

[0036] The active components (calculated as oxides) account for 10% to 40% (preferably 20-25%) of the total weight of the metal amine catalyst;

[0037] The amount of deionized water added is 5 to 10 times (for example, 6 to 8 times) the weight of the metal nitrate;

[0038] The programmed temperature rate is 9 to 11℃ / min.

[0039] Further improvement of the method for co-producing DMAEEM and DMDEE according to the present application: the preparation method of the metal amine catalyst is:

[0040] The active component consists of Cu, Ni and Co, and the mass ratio of Cu:Ni:Co is (13.5-22.5):(4.5-13.5):2 (preferably 18:9:2).

[0041] As a further improvement of the method for co-producing DMDEE from DMAEEM of the present invention: the present invention also provides a method for preparing polyurethane foam, using DMAEEM prepared by the method described above, the polyurethane foam formula is 90-100 parts of PPG (polypropylene glycol), 4-5 parts of water, 0.5-1.5 parts of silicone oil 815H, 0.1-0.5 parts of stannous octoate, 0.2-1.0 parts of DMAEEM, 10-15 parts of dichloromethane and 55-65 parts of TDI-80; the above parts are by mass.

[0042] That is, the DMAEEM obtained in the present invention can be used as a highly active foaming catalyst at low temperature (0-20° C.) for preparing polyurethane foam.

[0043] This invention proposes a one-pot process for preparing DMAEEM and co-producing DMDEE using diethylene glycol and morpholine as raw materials through amination catalyzed by a metal catalyst. While methods for preparing DMAEEM have been reported in the literature, its application has not been further explored. Testing in this invention demonstrates that it maintains high foaming activity at low temperatures and can replace DMDEE, a polyurethane foaming catalyst, in certain applications, demonstrating promising application prospects.

[0044] The synthetic route of the present invention is as follows:

[0045]

[0046] Synthetic route of 3DMAEEM co-production of DMDEE

[0047] The present invention prepares DMAEEM and co-produces DMDEE using the above-mentioned synthetic route, which has the following technical advantages:

[0048] 1. A new process route is used to prepare DMAEEM and co-produce DMDEE in a high-pressure reactor, with high product selectivity and simple separation;

[0049] 2. The amination catalysts of the two products can be used continuously in one pot, which is simple to operate; the excess morpholine and amination catalyst can be recycled and reused, reducing production costs;

[0050] 3. The DMAEEM of the present invention is used to prepare polyurethane foam, has high foaming activity at low temperatures, and is highly economical.

[0051] In summary, this synthetic route has the characteristics of novel route, low production cost and excellent product performance, so it has good application prospects and is suitable for industrial production. DETAILED DESCRIPTION

[0052] The present invention is further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto:

[0053] Example 1: A method for preparing DMAEEM and DMDEE, comprising the following steps:

[0054] 1) Preparation of metal catalyst:

[0055] To a reaction kettle, 17.1 g of copper nitrate trihydrate (containing 4.5 g of copper), 11.2 g of nickel nitrate hexahydrate (containing 2.25 g of nickel), 2.5 g of cobalt nitrate hexahydrate (containing 0.5 g of cobalt), and 33.5 g of aluminum oxide (containing 17.75 g of aluminum) were added in a mass ratio of Cu:Ni:Co:Al = 18:9:2:71. 200 g of deionized water was also added to the kettle, and the mixture was stirred and immersed at 50°C for 6 hours. The reaction solution was then placed in an oven at 120°C until the water was dried out. The solid obtained by drying the moisture was ground into powder and then placed in a muffle furnace for programmed temperature calcination. The programmed temperature was as follows: heating from room temperature to 200°C at a rate of 10°C / min, and calcining at 200°C for 0.5h; heating from 200°C to 300°C at a rate of 10°C / min, and calcining at 300°C for 0.5h; heating from 300°C to 400°C at a rate of 10°C / min, and calcining at 400°C for 1h; heating from 400°C to 500°C at a rate of 10°C / min, and calcining at 500°C for 4h. Finally, the powder was ground to pass through a 100-mesh sieve to obtain Cu / Ni / Co / Al metal catalyst I.

[0056] In this case, the active component (calculated as oxide) accounts for 21.4% of the total weight of the metal amination catalyst I.

[0057] 2) Reaction process:

[0058] 2.1) Add 212.2 g (2.0 mol) of diethylene glycol and 522.7 g (6.0 mol) of morpholine to a 1 L autoclave, and add 21.2 g of amination catalyst—Cu / Ni / Co / Al metal catalyst I—to the autoclave. The autoclave is then closed, and the atmosphere is replaced with nitrogen three times and hydrogen three times. After replacement, the autoclave is pressurized with hydrogen to an initial pressure of 1.5 MPa. The temperature is then raised to the reaction temperature, and the reaction is stirred for 10 hours at a temperature of 220° C. and a pressure of approximately 3.5 to 5.0 MPa (light components are generated during the reaction, resulting in an increase in pressure) to obtain reaction solution I. In addition to DMDEE and the intermediate 2-(2-morpholinoethoxy)ethanol, the reaction solution also contains unreacted morpholine and an amination catalyst.

[0059] 2.2) Set the reaction temperature to 190°C and the reaction pressure to 4.5 MPa;

[0060] After step 2.1), the autoclave was cooled to the set reaction temperature (190° C.), and dimethylamine was intermittently pumped into the autoclave using a plunger pump. A total of 67.6 g (1.5 mol) of dimethylamine was pumped into the autoclave within about 10 hours. After the dimethylamine was pumped in, the reaction was continued at 190° C. and a set reaction pressure of 4.5 MPa for 6 hours to obtain a reaction solution II. In addition to DMAEEM and DMDEE, the reaction solution II also contained unreacted dimethylamine, unreacted morpholine, and amination catalyst.

[0061] Note: During the intermittent pumping of dimethylamine, the pressure in the autoclave was controlled at 4.0-5.0 MPa. That is, when the pressure was higher than 5.0 MPa, the pumping of dimethylamine was stopped; when the pressure dropped to 4.0 MPa due to consumption of dimethylamine, the pumping of dimethylamine continued.

[0062] 2.3) After step 2.2), the obtained reaction solution II containing DMAEEM and DMDEE was cooled to 60°C, and the air release valve on the autoclave was slowly opened at this temperature to release unreacted dimethylamine, which was absorbed with water to obtain a 40% mass concentration of dimethylamine aqueous solution (about 50g); after the recovery of dimethylamine, the temperature was cooled to room temperature, the air release valve was opened, the autoclave was opened and allowed to stand for 4h, and filtered to obtain a filtrate and a filter cake, respectively. The filtrate was a mixed solution containing morpholine, DMAEEM and DMDEE; the filter cake was washed with water three times and then recovered to obtain a catalyst that can be used for recycling;

[0063] The filtrate was distilled, and the morpholine fraction at 50°C was collected at -0.1 MPa of a water pump, the fraction at 120°C was collected at a reduced pressure of 300 Pa of an oil pump, which was DMAEEM, and the fraction at 155°C was collected at a reduced pressure of 300 Pa of an oil pump, which was DMDEE.

[0064] Thus, 194.2 g of DMAEEM with a purity of 99.1% was obtained as a product, with a DMAEEM yield of 48.0%. 198.6 g of DMDEE with a purity of 99.5% was obtained as a product, with a DMDEE yield of 40.7%. The total yield of DMAEEM and DMDEE was 88.7%. 250 g of morpholine and 20 g of amination catalyst were recovered.

[0065] DMAEEM yield = actual amount of DMAEEM obtained by distillation / theoretical amount of DMAEEM;

[0066] DMDEE yield = amount of DMDEE actually obtained by distillation / amount of DMDEE theoretically obtained.

[0067] Example 2-1: Compared with Example 1, the following changes are made:

[0068] Cancel step 1);

[0069] The catalyst in step 2) was changed from the homemade amination catalyst in step 1) to commercial grade Raney Cu, and the weight remained unchanged at 21.2 g; the rest was the same as in Example 1.

[0070] Step 2) The final yield of DMAEEM is 43.3%, the yield of DMDEE is 36.6%, and the total yield is 79.9%.

[0071] Example 2-2: Compared with Example 1, the following changes are made:

[0072] Cancel step 1);

[0073] The catalyst in step 2) was changed from the homemade amination catalyst in step 1) to commercial grade Raney Ni, and the weight remained unchanged at 21.2 g; the rest was the same as in Example 1.

[0074] Step 2) The final yield of DMAEEM is 25.7%, the yield of DMDEE is 20.5%, and the total yield is 46.2%.

[0075] Example 3: Compared with Example 1, the following changes are made:

[0076] The amount of catalyst in step 2) was changed from 21.2 g to 10.6 g, and the rest was the same as in Example 1.

[0077] Step 2) The final yield of DMAEEM was 27.4%, the yield of DMDEE was 23.1%, and the total yield was 50.5%.

[0078] Example 4-1: Compared with Example 1, the following changes are made:

[0079] The initial hydrogen filling pressure in step 2.1) was changed from 1.5 MPa to 1.0 MPa. Accordingly, the pressure during the reaction at 220°C was approximately 3.0-4.5 MPa.

[0080] The set reaction pressure in step 2.2) remains unchanged, and the rest is the same as in Example 1.

[0081] Step 2) The final yield of DMAEEM is 46.2%, the yield of DMDEE is 38.6%, and the total yield is 84.8%.

[0082] Example 4-2: Compared with Example 1, the following changes are made:

[0083] The initial hydrogen filling pressure in step 2.1) was changed from 1.5 MPa to 2.0 MPa. Accordingly, the pressure during the reaction at 220°C was approximately 4.0-5.5 MPa.

[0084] The set reaction pressure in step 2.2) remains unchanged, and the rest is the same as in Example 1.

[0085] Step 2) The final yield of DMAEEM is 47.5%, the yield of DMDEE is 41.0%, and the total yield is 88.5%.

[0086] Example 5-1: With respect to Example 1, the following changes are made:

[0087] The reaction temperature in step 2.1) was changed from 220°C to 200°C, and the reaction time was changed from 10 h to 24 h; accordingly, the pressure during the reaction was about 2.8-4.0 MPa;

[0088] In step 2.2), the reaction temperature was changed to 180° C., the reaction pressure was kept unchanged, and the reaction time was changed from 16 h to 30 h; the rest was the same as in Example 1.

[0089] Step 2) The final yield of DMAEEM is 48.3%, the yield of DMDEE is 41.2%, and the total yield is 89.5%.

[0090] Example 5-2: Compared with Example 1, the following changes are made:

[0091] The initial reaction temperature in step 2.1) was changed from 220°C to 240°C, and the reaction time was changed from 10h to 5h; accordingly, the pressure during the reaction was 4.4-6.5MPa;

[0092] The reaction temperature in step 2.2) was changed to 200° C., the reaction pressure was kept unchanged, and the reaction time was changed to 10 h; the rest was the same as in Example 1.

[0093] The yield of DMAEEM obtained in step 2) is 37.5%, the yield of DMDEE is 32.8%, and the total yield is 70.3%.

[0094] Example 6, catalyst recycling:

[0095] Compared with Example 1, the "21.2 g amination catalyst" in step 2) is changed to "20 g of amination catalyst recovered in step 2) of Example 1 and 1.2 g of fresh amination catalyst". The rest is the same as Example 1.

[0096] The corresponding relationship between the number of times the catalyst was recycled and the results obtained is shown in Table 1 below.

[0097] Table 1 Effect of the number of times the amination catalyst is recycled on the yield

[0098]

[0099] Example 7-1: With respect to Example 1, the following changes are made:

[0100] 1) With respect to step 1) of Example 1:

[0101] The mass ratio of "Cu:Ni:Co:Al" in the preparation of the metal catalyst in step 1) was changed from "18:9:2:71" to "13.5:13.5:2:71", and thus 12.8 g of copper nitrate trihydrate (containing 3.375 g of copper), 16.8 g of nickel nitrate hexahydrate (containing 3.375 g of nickel), 2.5 g of cobalt nitrate hexahydrate (containing 0.5 g of cobalt), and 33.5 g of aluminum oxide (containing 17.75 g of aluminum) were used, and the rest was the same as in step 1) of Example 1; a Cu / Ni / Co / Al metal catalyst II was obtained; in this case, the active component (calculated as oxide) accounted for 20.5% of the total weight of the metal amination catalyst II.

[0102] 2) The Cu / Ni / Co / Al metal catalyst II obtained in step 1) was used to replace the Cu / Ni / Co / Al metal catalyst I. The weight remained unchanged during the reaction, still 21.2 g; the rest was the same as step 2) of Example 1.

[0103] The yield of DMAEEM was 46.1%, the yield of DMDEE was 41.5%, and the total yield was 87.6%.

[0104] Example 7-2: Compared with Example 1, the following changes are made:

[0105] 1) With respect to step 1) of Example 1:

[0106] The mass ratio of "Cu:Ni:Co:Al" in the preparation of the metal catalyst in step 1) was changed from "18:9:2:71" to "22.5:4.5:2:71", and thus 21.4 g of copper nitrate trihydrate (containing 5.625 g of copper), 5.6 g of nickel nitrate hexahydrate (containing 1.125 g of nickel), 2.5 g of cobalt nitrate hexahydrate (containing 0.5 g of cobalt), and 33.5 g of aluminum oxide (containing 17.75 g of aluminum) were used, and the rest was the same as in step 1) of Example 1; a Cu / Ni / Co / Al metal catalyst III was obtained; in this case, the active component (calculated as oxide) accounted for 21.4% of the total weight of the metal amination catalyst III.

[0107] 2) The Cu / Ni / Co / Al metal catalyst III obtained in step 1) was used to replace the Cu / Ni / Co / Al metal catalyst I. The weight remained unchanged during the reaction, still 21.2 g; the rest was the same as step 2) of Example 1.

[0108] The yield of DMAEEM was 50.6%, the yield of DMDEE was 37.3%, and the total yield was 87.9%.

[0109] Comparative Example 1: With respect to Example 1, the following changes were made:

[0110] 1) With respect to step 1) of Example 1:

[0111] The mass ratio of Cu:Ni:Co:Al in step 1) of the metal catalyst preparation was changed to a mass ratio of Cu, Zr, Al of 20:9:71. Thus, 19.0 g of copper nitrate trihydrate (containing 5.0 g of copper), 10.6 g of zirconium nitrate pentahydrate (containing 2.25 g of zirconium), and 33.5 g of aluminum oxide (containing 17.75 g of aluminum) were used to prepare a Cu / Zr / Al metal catalyst. The remaining steps were the same as those in step 1) of Example 1.

[0112] 2) The Cu / Zr / Al metal catalyst obtained in step 1) was used to replace the Cu / Ni / Co / Al metal catalyst I. The weight remained unchanged during the reaction, still 21.2 g. The rest was the same as step 2) of Example 1.

[0113] The yield of DMAEEM was 23.5%, the yield of DMDEE was 19.6%, and the total yield was 43.1%.

[0114] Experiment 1: DMAEEM was used as an amine catalyst to prepare polyurethane foam as follows:

[0115] The materials required for preparing polyurethane foam were placed in a constant temperature chamber at 15°C and allowed to stand for 24 hours. Then, 93 parts of PPG (polypropylene glycol), 4.8 parts of water, 0.8 parts of silicone oil 815H (silicone oil HGD-815H), 0.2 parts of stannous octoate, 0.8 parts of amine catalyst, and 12 parts of dichloromethane were added to a mixing barrel in sequence according to the mass parts. After mixing and stirring for 10 seconds with a stirrer at a speed of 2000 r / min, the mixture was allowed to stand for 1 minute. Then, 58 parts of toluene diisocyanate (TDI-80) with a 2,4-body content of 80% were added to the mixing barrel. The temperature was controlled at 15°C, the timing was started, and after rapid stirring at 2000 r / min for 2 seconds (the purpose was to ensure uniform mixing of the raw materials and reduce the mixing of air), the mixture was poured into a foaming box for foaming. After ripening, it was cut into the required size and performance tested.

[0116] Silicone oil HGD-815H was purchased from Hengguang New Material (Jiangsu) Co., Ltd.

[0117] 2,4 body content of 80% of toluene diisocyanate (TDI-80), that is, containing 2,4-TDI 80%, 2,6-TDI 20%.

[0118] Experiment 2, change DMAEEM in experiment 1 to DMDEE, the rest is the same as experiment 1.

[0119] Under the same experimental conditions, the foaming effect of DMAEEM and DMDEE was compared, and the corresponding foaming data obtained are listed in Table 2.

[0120] Table 2 Comparison of polyurethane foaming data obtained by DMAEEM and DMDEE

[0121] Amine catalyst Start time Curing time Foam smell DMDEE 108s 540s No irritating odor DMAEEM 74s 100s No irritating odor

[0122] From the foaming data in Table 2, it can be concluded that DMAEEM has higher foaming activity at low temperature than DMDEE, and can replace polyurethane foaming catalyst DMDEE in some fields.

[0123] Finally, it should also be noted that the above only lists several specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, but can also have many variations. All variations that can be directly derived or inferred from the disclosed content by those of ordinary skill in the art should be considered within the scope of the present application.

Claims

1. A method for co-producing DMDEE from DMAEEM, characterized in that: Using diethylene glycol and morpholine as raw materials and an amination catalyst, DMAEEM is prepared in one pot and DMDEE is co-produced. The following steps are involved: 1) Add diethylene glycol and morpholine to an autoclave, add an amination catalyst to the autoclave, replace the gas in the autoclave with an inert gas, and then introduce hydrogen into the autoclave until the pressure reaches 1.0-3.0 MPa. Then, heat the autoclave to 200-250° C. and react at a pressure of 2.8-8.0 MPa for 5-25 hours to obtain a reaction solution I, which contains DMDEE and 2-(2-morpholinoethoxy)ethanol. The amination catalyst is any one of the following: Raney Cu, Raney Ni, or a metal amination catalyst; The preparation method of the metal amination catalyst is: A metal nitrate providing an active component and alumina as a carrier are added to a reactor, and deionized water is added. The mixture is stirred and impregnated at 50±10°C for 6±1 h. The water is then dried. The resulting solid is ground into a powder and then subjected to a programmed temperature roasting process. The programmed temperature roasting process is as follows: heating from room temperature to 200±20°C and holding the temperature for 0.5±0.1 h; then heating to 300±20°C and holding the temperature for 0.5±0.1 h; then heating to 400±20°C and holding the temperature for 1±0.1 h; and finally heating to 500±20°C and holding the temperature for 4±0.1 h to prepare a metal amination catalyst. The active component is composed of Cu, Ni, and Co, wherein the ratio of Cu:Ni:Co is 13.5-22.5:4.5-13.5:2; The active component accounts for 10% to 40% of the total weight of the metal amination catalyst, and the active component is calculated as oxide; 2) Cooling the reaction solution I obtained in step 1) to 170-220°C, intermittently pumping dimethylamine into the autoclave, and reacting at 170-220°C under a set reaction pressure for 5-30 hours to obtain a reaction solution II, wherein the reaction solution II contains DMAEEM and DMDEE; The reaction pressure is set to 2.0~8.0 MPa; The molar ratio of diethylene glycol:morpholine:dimethylamine is 1:(1.5~5.0):(0.5~2.0); the amination catalyst is 1%~40% of the mass of diethylene glycol; 3) After step 2), the obtained reaction solution II is cooled to 60±10°C, and then the air is released through the air release valve of the autoclave; The temperature was then lowered to room temperature, the kettle was opened and allowed to stand, the product obtained was filtered, and the filtrate was distilled to obtain morpholine, DMAEEM and DMDEE, respectively.

2. The method for co-producing DMAEEM with DMDEE according to claim 1, wherein: The intermittent pumping of dimethylamine in step 2) is as follows: when the pressure rises above the set pressure by 0.5 MPa, the pumping of dimethylamine is stopped; conversely, when the pressure drops to 0.5-1 MPa below the set pressure, the pumping of dimethylamine is continued.

3. the method for DMAEEM co-production DMDEE according to claim 1 or 2, is characterized in that In the step 3): The dimethylamine released from the air release valve is absorbed by water to obtain a dimethylamine aqueous solution; The morpholine recovered by distillation in step 3) can be used in the next batch of reactions; The filter cake obtained by filtration in step 3) is washed with water to be used as an amination catalyst and can be used in the next batch of reactions.

4. The method for co-producing DMAEEM with DMDEE according to claim 3, wherein: The molar ratio of diethylene glycol:morpholine:dimethylamine = 1:2.9~3.1:0.7~0.8; The amination catalyst is 10% to 15% of the mass of diethylene glycol.

5. The method for co-producing DMDEE from DMAEEM according to claim 4, wherein: The metal nitrate is selected from Cu(NO3)2, Ni(NO3)2, Co(NO3)2; The heating rate is 9~11℃ / min; The amount of deionized water is 5 to 10 times the weight of the metal nitrate.

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