Polyvinylamine-based polymers, methods of making and using the same

Abstract

The application relates to the field of organic synthesis and discloses a polyvinylamine polymer, a preparation method and application thereof. The polyvinylamine polymer contains structural unit B shown in formula (2), structural unit C shown in formula (3) and optional structural unit A shown in formula (1); the content of the structural unit C is above 5% by weight; wherein R is methyl or ethyl. The polyvinylamine polymer of the application has a C-C bond as a main chain and better temperature resistance. The method of the application can obtain secondary amines and tertiary amines without generating quaternary ammonium salts, and the method can realize adjustable proportions of primary amines, secondary amines and tertiary amines.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, and more specifically, to polyethyleneamine polymers, their preparation methods, and applications. Background Technology

[0002] Polyvinylamine (PVC) is a chain-like, water-soluble polymer with highly reactive amino groups in its side chains. Because amino groups readily form positive charges, it exhibits high cationicity and can form polyelectrolyte complexes with oppositely charged polymers over a wide pH range. Furthermore, it can undergo most reactions of the amino groups, thus acquiring unique physicochemical properties and finding wide applications in papermaking, water treatment, enhanced oil recovery, adhesives, and metal ion complexation. Although PVC has a simple structure, its synthesis is extremely difficult. Due to the high instability of ethyleneamine, PVC cannot be prepared through the polymerization of ethyleneamine monomers. The main methods for preparing PVC are the Hofmann degradation reaction of polyacrylamide and the hydrolysis of poly(N-acyl)ethyleneamine.

[0003] Secondary and tertiary amines are important raw materials and intermediates in organic synthesis, with wide applications in pharmaceuticals, pesticides, food, and water treatment. Tertiary amines are chemical substances with significant applications, widely used in medicine, agriculture, food, and cosmetics. Although polyacrylamide can be partially aminationd via the Hofmann degradation rearrangement reaction to obtain polyethyleneamines with different degrees of amination, side reactions occur, leading to low conversion rates. Polyethyleneamine can be obtained by hydrolysis of poly(N-acyl)ethyleneamine, which has high commercial value; however, hydrolysis generally yields primary amines, not secondary or tertiary amines. While reacting the obtained polyethyleneamine with haloalkanes can yield secondary or tertiary amines, this usually involves the formation of quaternary ammonium salts.

[0004] Polyethyleneimine contains primary, secondary, and tertiary amines, exhibiting high reactivity. However, its main chain is dominated by C-C bonds, resulting in poor high-temperature thermal stability, and the raw materials are highly toxic and expensive. Therefore, developing a low-cost polymer with C-C bonds as the main chain and containing high levels of tertiary amines, along with its synthetic method, is of great significance. Summary of the Invention

[0005] The purpose of this invention is to overcome the difficulties in preparing polyethyleneamine in the prior art, and the problem that quaternary ammonium salts are generated. This invention provides polyethyleneamine polymers, their preparation methods and applications. The method of this invention can prepare polyethyleneamine polymers with C-C bonds as the main chain, containing a certain proportion of primary amines, secondary amines and tertiary amines. The reaction is mild, the cost is low, and no quaternary ammonium salts are generated.

[0006] To achieve the above objectives, the first aspect of the present invention provides a polyethyleneamine polymer, the polyethyleneamine polymer containing structural unit B shown in formula (2), structural unit C shown in formula (3), and optionally structural unit A shown in formula (1); the content of structural unit C is 5% by weight or more;

[0007]

[0008] Where R is methyl or ethyl.

[0009] A second aspect of the present invention provides a method for preparing a polyethyleneamine polymer, the method comprising: performing an addition reaction between the polymer and an aldehyde compound to obtain an amino alcohol; wherein the polymer contains structural unit A as shown in formula (1) and / or structural unit B as shown in formula (2);

[0010] The amino alcohol is dehydrated to form an imine and / or imine ion intermediate, and then a reductive amination reaction is carried out.

[0011]

[0012] Where R is methyl or ethyl.

[0013] A third aspect of the present invention provides a polyethyleneamine polymer prepared by the preparation method described in the second aspect above.

[0014] The fourth aspect of the present invention provides the application of polyethyleneamine polymers as described in the first and third aspects above in papermaking, water treatment, oilfield additives or acid gas absorption.

[0015] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0016] (1) The polyethyleneamine polymers provided by the present invention have C-C bonds as the main chain and contain highly active secondary amines, tertiary amines and optional primary amines in the side chains. Their binding ability with hydrogen ions in aqueous solution is different, and polymers with different cation densities can be obtained.

[0017] (2) The polyethyleneamine polymer of the present invention can be used as a crosslinking agent to form a gel with good temperature resistance with polymers containing amide groups. The gel can be used as a plugging agent for high-temperature and high-salt oil reservoirs to block high-permeability channels. The polyethyleneamine polymer of the present invention can also be used as an absorbent material for acidic gases, and has good adsorption performance for acidic gases such as CO2.

[0018] (3) The method of the present invention does not produce quaternary ammonium salts while obtaining secondary and tertiary amines. Furthermore, the method can achieve adjustable ratio of primary, secondary and tertiary amines, the raw materials are readily available, and the reaction conditions are mild. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] The first aspect of the present invention provides a polyethyleneamine polymer, the polyethyleneamine polymer containing structural unit B of formula (2), structural unit C of formula (3), and optionally structural unit A of formula (1); the content of structural unit C is 5% by weight or more;

[0021]

[0022] Where R is methyl or ethyl.

[0023] Preferably, R is a methyl group.

[0024] According to the present invention, the three structural units A, B and C can be segmented, alternately connected or randomly connected in any order.

[0025] According to the present invention, the polyethyleneamine polymer has C-C bonds as the main chain, which has better temperature resistance. At the same time, the side chains contain highly active secondary amines, tertiary amines and optional primary amines, and the densities of primary, secondary and tertiary amines can be adjusted. Their binding ability with hydrogen ions in aqueous solution is different (tertiary amine > secondary amine > primary amine), so polymers with different cation densities can be obtained.

[0026] According to some embodiments of the present invention, based on the total weight of the polyethyleneamine polymer, the content of structural unit A is 0-85% by weight, the content of structural unit B is 5-95% by weight, and the content of structural unit C is 5-90% by weight.

[0027] According to a preferred embodiment of the present invention, based on the total weight of the polymer, the content of structural unit A is 0-85% by weight, for example, 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, and any value within any range of any two values, preferably 5-40% by weight.

[0028] According to a preferred embodiment of the present invention, based on the total weight of the polymer, the content of the structural unit B is 5-95% by weight, for example, 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 95% by weight, and any value within any range of any two values, preferably 10-80% by weight.

[0029] According to a preferred embodiment of the present invention, the content of the structural unit C is 5-90 wt%, based on the total weight of the polymer, for example, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, and any value within any range of any two values, more preferably 20-85 wt%.

[0030] According to some preferred embodiments of the present invention, based on the total weight of the polyethyleneamine polymer, the content of structural unit A is 5-40% by weight, the content of structural unit B is 10-80% by weight, and the content of structural unit C is 20-85% by weight.

[0031] In addition to the structural units shown in formulas (1), (2) and (3) above, the polyethyleneamine polymers of the present invention may also contain other structural units.

[0032] According to some embodiments of the present invention, the polyethyleneamine polymer further contains structural units from at least one of 2-acrylamido-2-methylpropanesulfonic acid (sodium), N,N-dimethylacrylamide, acrylamide, N-vinylpyrrolidone, vinyl acetate, acrylonitrile, dimethylaminoethyl methacrylate, styrene sulfonic acid, vinyl sulfonic acid, acrylic acid, and their salts.

[0033] According to some embodiments of the present invention, the polyethyleneamine polymer does not contain a quaternary ammonium salt structure.

[0034] According to some embodiments of the present invention, the content of quaternary ammonium salt structure is 0, based on the total weight of the polyethyleneamine polymer.

[0035] According to some embodiments of the present invention, the number average molecular weight of the polyethyleneamine polymer is 10,000 to 1,000,000 g / mol, for example, 1000 g / mol, 10,000 g / mol, 20,000 g / mol, 50,000 g / mol, 80,000 g / mol, 100,000 g / mol, 200,000 g / mol, 300,000 g / mol, 400,000 g / mol, 500,000 g / mol, 600,000 g / mol, 700,000 g / mol, 800,000 g / mol, 900,000 g / mol, 1,000,000 g / mol, and any value within any range of any two values.

[0036] A second aspect of the present invention provides a method for preparing a polyethyleneamine polymer, the method comprising: performing an addition reaction between the polymer and an aldehyde compound to obtain an amino alcohol; wherein the polymer contains structural unit A as shown in formula (1) and / or structural unit B as shown in formula (2);

[0037] The amino alcohol is dehydrated to form an imine and / or imine ion intermediate, and then a reductive amination reaction is carried out.

[0038]

[0039] Where R is methyl or ethyl.

[0040] Preferably, R is a methyl group.

[0041] According to the present invention, if the polymer contains only structural unit A as shown in formula (1), then the obtained polyethyleneamine polymer may simultaneously contain structural unit A as shown in formula (1), structural unit B as shown in formula (2), and structural unit C as shown in formula (3). The proportion of each structural unit can be adjusted by controlling the reaction.

[0042] According to the present invention, if the polymer contains only structural unit B as shown in formula (2), then the obtained polyethyleneamine polymer may contain both structural unit B as shown in formula (2) and structural unit C as shown in formula (3). The proportion of each structural unit can be adjusted by controlling the reaction.

[0043] According to the present invention, if the polymer contains both structural unit A shown in formula (1) and structural unit B shown in formula (2), then the resulting polyethyleneamine polymer may contain both structural unit A shown in formula (1), structural unit B shown in formula (2), and structural unit C shown in formula (3). The proportion of each structural unit can be adjusted by controlling the reaction.

[0044] According to this invention, this method yields secondary and tertiary amines without generating quaternary ammonium salts, and the ratio of primary, secondary, and tertiary amines is adjustable. The raw materials are readily available, and the reaction conditions are mild. This method is a reductive amination reaction, in which formaldehyde reacts with primary or secondary amines in the presence of formic acid to generate secondary or tertiary amines. Under acidic conditions provided by formic acid, the primary or secondary amine undergoes an addition reaction with formaldehyde to give hydroxylamine, which then undergoes dehydration to generate a carbon-nitrogen double bond, i.e., an imine. Finally, the imine intermediate is reduced in the presence of formic acid to obtain the product.

[0045] The method of this invention can prevent the formation of quaternary ammonium salts because the intermediate hydroxylamine in this reaction requires the presence of a hydrogen atom on the nitrogen atom to dehydrate and yield an imine. Since the hydrogen atom in the tertiary amine is replaced by an alkyl group, the imine intermediate cannot be obtained, thus preventing the formation of quaternary ammonium salts. Quaternary ammonium salts, however, lead to a decrease in the content of tertiary amines. Furthermore, the cationic nature of quaternary ammonium salts can affect the function of surrounding tertiary or primary amines. As a crosslinking agent, it can affect the reaction between surrounding primary or tertiary amines and amide groups. As an acidic gas absorbent material, it can affect the absorption efficiency of tertiary amines.

[0046] According to some embodiments of the present invention, the polymer is selected from copolymers or homopolymers formed by polymerization of free monomers; the free monomers include N-vinylformamide and / or N-methyl-N-vinylformamide.

[0047] Preferably, the polymeric monomer further includes at least one of 2-acrylamido-2-methylpropanesulfonic acid (sodium), N,N-dimethylacrylamide, acrylamide, N-vinylpyrrolidone, vinyl acetate, acrylonitrile, dimethylaminoethyl methacrylate, styrene sulfonic acid, vinyl sulfonic acid, acrylic acid, and their salts.

[0048] The present invention does not impose any particular requirements on the preparation method of the polymer containing structural unit A of formula (1) and / or structural unit B of formula (2). Those skilled in the art can determine a suitable synthesis method by combining the structural formula provided by the present invention with commonly used methods in the fields of organic synthesis and free radical polymerization. The source can be a copolymer or homopolymer formed by polymerization of N-vinylformamide and / or N-methyl-N-vinylformamide, or it can be the Hoffman degradation product of polyacrylamide.

[0049] According to some embodiments of the present invention, the polymer is obtained by Hoffman degradation of polyacrylamide.

[0050] According to some embodiments of the present invention, the aldehyde compound is selected from formaldehyde and / or acetaldehyde, preferably formaldehyde.

[0051] According to some embodiments of the present invention, the temperature of the addition reaction is 30-60°C, preferably 40-50°C; the pH is 1-3, preferably 1-2; and the time is 1-6h, preferably 2-5h.

[0052] According to some embodiments of the present invention, the reductive amination reaction is selected from catalytic hydrogenation reduction reaction, metal hydride reduction reaction, borane reduction reaction or formic acid reduction reaction.

[0053] According to some embodiments of the present invention, the reductive amination reaction is a formic acid reduction reaction, the reaction temperature is 80-100℃, preferably 85-95℃, and the reaction time is 4-11h, preferably 6-10h.

[0054] According to some embodiments of the present invention, in the system of the reductive amination reaction, the molar ratio of the aldehyde compound to formic acid is 1:0.8-8, for example, 1:0.8, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, and any value within the range of any two values, preferably 1:1-6.

[0055] According to the present invention, in the reductive amination reaction system, in addition to the added formic acid, formic acid is also generated during the preparation process. This is because sodium formate released during polymer hydrolysis can be converted into formic acid by adjusting the pH. For example, formic acid is generated by the hydrolysis of polymers formed from N-vinylformamide monomers. Therefore, the amount of formic acid in the reductive amination reaction system is greater than the actual amount of formic acid added.

[0056] In this invention, formic acid is obtained partly by hydrolyzing a polymer containing structural unit A as shown in formula (1) and / or structural unit B as shown in formula (2) under alkaline or acidic conditions, and partly by additional addition.

[0057] The inventors of this invention have discovered that the reaction can be carried out under mild conditions according to the method described above to obtain a polyethyleneamine polymer containing high tertiary amines with adjustable primary, secondary, and tertiary amines. The method provided by this invention does not produce quaternary ammonium salts while obtaining secondary and tertiary amines, thus reducing the influence of quaternary ammonium salts on tertiary amines.

[0058] In this invention, there is no particular limitation on the amount of each raw material used in the preparation of the polymer, and the amount of each raw material can be adjusted according to the actual needs of primary, secondary and tertiary amines.

[0059] According to the present invention, the preparation method may further include: after completing the reductive amination reaction, subjecting the polymer solution to vacuum distillation to remove unreacted aldehyde compounds and formic acid, thereby obtaining the polymer solution product.

[0060] According to the present invention, after obtaining the polymer solution product, it can also be subjected to vacuum distillation as needed to remove a portion of the water, thereby obtaining polymer solution products with different contents.

[0061] According to the present invention, the pressure of the vacuum distillation is 900-2000 kPa, and the temperature is 40-70°C, preferably 45-65°C. In the present invention, the vacuum distillation time is not specifically limited and can be adjusted according to actual needs.

[0062] A third aspect of the present invention provides a polyethyleneamine polymer prepared by the preparation method described in the second aspect above.

[0063] The polyethyleneamine polymers of this invention have C-C bonds as the main chain and serve as crosslinking agents. The gels formed with polymers containing amide groups have better temperature resistance. They also contain primary amines, a large amount of highly active secondary amines and tertiary amines, and have the advantage of adjustable ratios of primary, secondary and tertiary amines. They can be used as polymers with high cation density and have good adsorption capacity for acidic gases such as CO2.

[0064] The fourth aspect of the present invention provides the application of polyethyleneamine polymers as described in the first and third aspects above in papermaking, water treatment, oilfield additives or acid gas absorption.

[0065] According to the present invention, acidic gases are absorbed, such as carbon dioxide and hydrogen sulfide.

[0066] The polyethyleneamine polymers of the present invention can be used as crosslinking agents to form gels with good temperature resistance with polymers containing amide groups. These gels can be used as plugging agents in high-temperature and high-salinity oil reservoirs to seal high-permeability channels. The polyethyleneamine polymers of the present invention can also be used as absorbent materials for acidic gases, exhibiting good adsorption performance for acidic gases such as CO2.

[0067] The present invention will be described in detail below through embodiments. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0068] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0069] The testing method is as follows:

[0070] 1) The determination of primary, secondary and tertiary amine content was carried out in accordance with the method in "Analysis of Primary, Secondary and Tertiary Amine Content in Polyethyleneimine by Potentiometric Titration", Yunnan Chemical Industry, 2018, Vol. 45, No. 10, pp. 122-123.

[0071] 2) The determination method for quaternary ammonium salts was chemical titration, referring to "Research on the Determination of Quaternary Ammonium Salts by Sodium Tetraphenylborate Back Titration", Journal of Xi'an Petroleum University (Natural Science Edition), 2009, Vol. 24, No. 4, pp. 62-63.

[0072] 3) Number-average molecular weight determination: Molecular weight was determined using a gel permeation chromatograph. The test conditions were as follows: a polymer solution of approximately 1% (w / v) was prepared and injected into the gel permeation chromatograph using a microsyringe. The mobile phase was 0.1 mol / L NaCl, the temperature was 30℃, and the flow rate was maintained at 1.0 mL per minute.

[0073] Example 1

[0074] (1) Take 50g of N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1.5g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2 wt% ammonium persulfate aqueous solution, and 0.8g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0075] (2) Take 50g of the reaction solution obtained in step (1), add 32.3g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0076] (3) Adjust the pH to 1.0 with sulfuric acid, add 24.6 g of formaldehyde aqueous solution (37 wt%), react at 40 °C for 2 h, then add 16.2 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P1.

[0077] Polyethyleneamine polymer P1 contains structural units as shown in formula (1), formula (2) and formula (3), where R is methyl.

[0078] The obtained polyethyleneamine polymer P1 was detected using a TENSOR 27 infrared spectrometer (Bruker, Germany), at 3450 cm⁻¹. -1 and 3400cm -1 The characteristic absorption peaks for the antisymmetric and symmetric contractile vibrations of primary amine -NH2 are at 3200 cm⁻¹. -1 The characteristic absorption peak of secondary amines is 2700 cm⁻¹. -1 -2250cm -1 The broad peak at this point is a characteristic absorption peak of tertiary amines, confirming the existence of three structural units.

[0079] The number average molecular weight of the polyethyleneamine polymer was determined to be 96,000 g / mol. It contained 25% by weight of primary amine structural units of formula (1), 25% by weight of secondary amine structural units of formula (2), and 50% by weight of tertiary amine structural units of formula (3). Quaternary ammonium salts were not detected.

[0080] Example 2

[0081] (1) Take 30g of N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1.5g of 0.25% by weight of 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2% by weight of ammonium persulfate aqueous solution, and 0.8g of 0.3% by weight of sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0082] (2) Take 15g of the reaction solution obtained in step (1), add 0.49mol of hydrochloric acid while stirring, react at 80℃ for 6h, and then cool to room temperature.

[0083] (3) Adjust the pH to 1.5 with sulfuric acid, add 4.5 g of formaldehyde aqueous solution (37 wt%), react at 30 °C for 5 h, then add 2.5 g of formic acid, and react at 90 °C for 7 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation. After drying the reaction solution, obtain polyethyleneamine polymer P2.

[0084] Polyethyleneamine polymer P2 contains structural units as shown in formula (1), formula (2) and formula (3), where R is methyl.

[0085] The number average molecular weight of the polyethyleneamine polymer P2 was determined to be 18000 g / mol, wherein the content of primary amine structural unit of formula (1) was 30 wt%, the content of secondary amine structural unit of formula (2) was 30 wt%, the content of tertiary amine structural unit of formula (3) was 40 wt%, and quaternary ammonium salt was not detected.

[0086] Example 3

[0087] (1) Take 45g of N-methyl-N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 2g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2 wt% ammonium persulfate aqueous solution, and 1g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 6 hours.

[0088] (2) Take 15g of the reaction solution obtained in step (1), add 0.05mol of hydrochloric acid while stirring, react at 90℃ for 10h, and then cool to room temperature.

[0089] (3) Adjust the pH to 1 with sulfuric acid, add 3.5 g of formaldehyde aqueous solution (37 wt%), react at 50 °C for 3 h, then add 2.7 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P3.

[0090] Polyethyleneamine polymer P3 contains structural units as shown in formulas (2) and (3), where R is methyl.

[0091] The number average molecular weight of the polyethyleneamine polymer P3 was determined to be 45,000 g / mol, with a secondary amine structural unit content of 25% by weight, a tertiary amine structural unit content of 75% by weight, and no quaternary ammonium salt detected.

[0092] Example 4

[0093] (1) Take 50g of N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2 wt% ammonium persulfate aqueous solution, and 0.8g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0094] (2) Take 50g of the reaction solution obtained in step (1), add 31.3g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0095] (3) Adjust the pH to 2.0 with sulfuric acid, add 13g of acetaldehyde, react at 40℃ for 2h, then add 14.7g of formic acid, and react at 95℃ for 6h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P4.

[0096] Polyethyleneamine polymer P4 contains structural units as shown in formulas (1), (2) and (3), where R is ethyl.

[0097] The number average molecular weight of the polyethyleneamine polymer P4 was determined to be 73,000 g / mol, wherein the content of primary amine structural unit of formula (1) was 25 wt%, the content of secondary amine of formula (2) was 50 wt%, the content of tertiary amine structural unit of formula (3) was 25 wt%, and quaternary ammonium salt was not detected.

[0098] Example 5

[0099] (1) Take 12.5g N-vinylformamide and 12.5g N-methyl-N-vinylformamide, dissolve them in 100g deionized water, control the initial temperature at 12℃, purge the system with nitrogen gas for 20min to remove oxygen, and then add 1.5g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.8g of 0.2 wt% ammonium persulfate aqueous solution, and 1g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen gas and continue the reaction for 4 hours.

[0100] (2) Take 50g of the reaction solution obtained in step (1), add 17.2g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0101] (3) Adjust the pH to 1.0 with sulfuric acid, add 5.3 g of formaldehyde aqueous solution (37 wt%), react at 40 °C for 2 h, then add 2.7 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P5.

[0102] Polyethyleneamine polymer P5 contains structural units as shown in formulas (1), (2) and (3), where R is methyl.

[0103] The number average molecular weight of the polyethyleneamine polymer P5 was determined to be 6500 g / mol, wherein the content of primary amine (1) was 40 wt%, the content of secondary amine (2) was 18 wt%, the content of tertiary amine structural unit (3) was 42 wt%, and quaternary ammonium salt was not detected.

[0104] Example 6

[0105] (1) Dissolve 40g of N-vinylformamide and 10g of acrylamide in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1.5g of 0.25% by weight of 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2% by weight of ammonium persulfate aqueous solution, and 0.8g of 0.3% by weight of sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0106] (2) Take 50g of the reaction solution obtained in step (1), add 31.3g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0107] (3) Adjust the pH to 1.0 with sulfuric acid, add 18.3 g of formaldehyde aqueous solution (37 wt%), react at 40 °C for 2 h, then add 19.5 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P6.

[0108] Polyethyleneamine polymer P6 contains structural units shown in formulas (1), (2), and (3), where R is methyl, and also contains... Structural unit.

[0109] The number-average molecular weight of the polyethyleneamine polymer P6 was determined to be 490,000 g / mol, containing 8% by weight of primary amine structural units of formula (1), 48% by weight of secondary amine structural units of formula (2), and 24% by weight of tertiary amine structural units of formula (3). The content of structural units was 20% by weight, and quaternary ammonium salts were not detected.

[0110] Example 7

[0111] (1) Dissolve 40g of N-vinylformamide and 10g of sodium acrylate in 100g of deionized water. Control the initial temperature at 12℃ and purge the system with nitrogen for 20min to remove oxygen. Then add 1.5g of 0.25% by weight of 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2% by weight of ammonium persulfate aqueous solution, and 0.8g of 0.3% by weight of sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0112] (2) Take 50g of the reaction solution obtained in step (1), add 25g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0113] (3) Adjust the pH to 1.0 with sulfuric acid, add 12.2 g of formaldehyde aqueous solution (37 wt%), react at 40 °C for 2 h, then add 9.3 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P7.

[0114] Polyethyleneamine polymer P7 contains structural units shown in formulas (1), (2), and (3), where R is methyl, and also contains... Structural unit.

[0115] The number-average molecular weight of the polyethyleneamine polymer P7 was determined to be 405,000 g / mol. It contained 32% by weight of primary amine structural units (1), 32% by weight of secondary amine structural units (2), and 16% by weight of tertiary amine structural units (3). The content of structural units was 20% by weight, and quaternary ammonium salts were not detected.

[0116] Example 8

[0117] (1) Dissolve 40g of N-vinylformamide and 10g of sodium 2-acrylamido-2-methyl-propanesulfonate in 100g of deionized water. Control the initial temperature at 12℃ and purge the system with nitrogen for 20min to remove oxygen. Then add 1.5g of 0.25% by weight of 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2% by weight of ammonium persulfate aqueous solution, and 0.8g of 0.3% by weight of sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0118] (2) Take 50g of the reaction solution obtained in step (1), add 25g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0119] (3) Adjust the pH to 1.0 with sulfuric acid, add 11.4 g of formaldehyde aqueous solution (37 wt%), react at 40 °C for 2 h, then add 15.0 g of formic acid, and react at 85 °C for 8 h. After the reaction is complete, remove unreacted formaldehyde and formic acid by vacuum distillation to obtain polyethyleneamine polymer P8.

[0120] Polyethyleneamine polymer P8 contains structural units shown in formulas (1), (2), and (3), where R is methyl, and also contains... Structural unit.

[0121] The number-average molecular weight of the polyethyleneamine polymer P8 was determined to be 223,500 g / mol, containing 40% by weight of primary amine structural units of formula (1), 20% by weight of secondary amine structural units of formula (2), and 20% by weight of tertiary amine structural units. The content of structural units was 20% by weight, and quaternary ammonium salts were not detected.

[0122] Example 9

[0123] Similar to Example 3, except that in step (3), the pH was adjusted to 1 with sulfuric acid, 5.5 g of formaldehyde aqueous solution (37% by weight) was added, and the reaction was carried out at 50°C for 3 h. Then, 4.7 g of formic acid was added, and the reaction was carried out at 85°C for 8 h. After the reaction was completed, the unreacted formaldehyde and formic acid were removed by vacuum distillation to obtain the polyethyleneamine polymer P9.

[0124] Polyethyleneamine polymer P9 contains structural units as shown in formulas (2) and (3), where R is methyl.

[0125] The number average molecular weight of the polyethyleneamine polymer P9 was determined to be 47,100 g / mol, of which the content of secondary amine structural units of formula (2) was 10 wt%, the content of tertiary amine structural units of formula (3) was 90 wt%, and quaternary ammonium salts were not detected.

[0126] Comparative Example 1

[0127] (1) Take 12.5g N-vinylformamide and 12.5g N-methyl-N-vinylformamide, dissolve them in 100g deionized water, control the initial temperature at 12℃, purge the system with nitrogen gas for 20min to remove oxygen, and then add 1.5g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.8g of 0.2 wt% ammonium persulfate aqueous solution, and 1g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen gas and continue the reaction for 4 hours.

[0128] (2) Take 50g of the reaction solution obtained in step (1), add 17.2g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, cool to room temperature, remove the formic acid produced by hydrolysis by vacuum distillation, and obtain polyethyleneamine polymer D1.

[0129] The number average molecular weight of polyethyleneamine polymer D1 was determined to be 5100 g / mol. It contained only the structural units shown in formula (1) and formula (2), and the content of the primary amine structural unit of formula (1) was 47.6 wt%, and the content of the secondary amine structural unit of formula (2) was 52.4 wt%.

[0130] Comparative Example 2

[0131] (1) Take 50g of N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1.5g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2 wt% ammonium persulfate aqueous solution, and 0.8g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0132] (2) Take 50g of the reaction solution obtained in step (1), add 32.3g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, cool to room temperature, remove the formic acid produced by hydrolysis by vacuum distillation, and obtain polyethyleneamine polymer D2.

[0133] It was determined that the polyethyleneamine polymer D2 contains only the structural unit shown in formula (1). The number-average molecular weight of the polyethyleneamine polymer D2 was determined to be 84630 g / mol.

[0134] Comparative Example 3

[0135] (1) Take 50g of N-vinylformamide, dissolve it in 100g of deionized water, control the initial temperature at 12℃, purge the system with nitrogen for 20min to remove oxygen, and then add 1.5g of 0.25 wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 1.2g of 0.2 wt% ammonium persulfate aqueous solution, and 0.8g of 0.3 wt% sodium bisulfite aqueous solution to initiate polymerization. After the system temperature rises by 0.5℃, stop purging with nitrogen and continue the reaction for 4 hours.

[0136] (2) Take 50g of the reaction solution obtained in step (1), add 32.3g of sodium hydroxide solution with a mass fraction of 30% under stirring, react at 80℃ for 5h, and then cool to room temperature.

[0137] (3) Add 43.1 g of iodomethane, 25.5 g of sodium bicarbonate and 50 g of ethanol, and react at room temperature for 8 h. After the reaction is complete, remove ethanol and unreacted iodomethane by vacuum distillation to obtain polyethyleneamine polymer D3.

[0138] Polyethyleneamine polymer D3 contains structural units as shown in formula (1), formula (2), and formula (3).

[0139] The number average molecular weight of the polyethyleneamine polymer D3 was determined to be 103,000 g / mol, containing 23% by weight of primary amine structural units of formula (1), 20% by weight of secondary amine structural units of formula (2), 42% by weight of tertiary amine structural units of formula (3), and 15% by weight of quaternary ammonium salt units.

[0140] The results above show that the polyethyleneamine polymers obtained by the method provided in this invention contain primary amines, a large amount of highly reactive secondary amines, and tertiary amines, and have the advantage of adjustable ratios of primary, secondary, and tertiary amines. The method provided in this invention does not produce quaternary ammonium salts while obtaining secondary and tertiary amines. The method uses readily available raw materials and operates under mild reaction conditions.

[0141] Application Example 1

[0142] This application example illustrates the use of polyethyleneamine polymers as crosslinking agents in the field of oilfield additives.

[0143] 4g of acrylamide / sodium acrylate / sodium 2-acrylamido-2-methylpropanesulfonate copolymer (molecular weight 26 million, sodium acrylate structural unit content 22% by weight) was added to 900g of simulated brine (mineralization 100000mg / L, calcium and magnesium ion content 2000mg / L). After stirring at 600rpm / min until completely dissolved, 3g of polymers P1-P2 prepared in Examples 1-2, polymers P4-P8 prepared in Examples 4-8, and polyethyleneamine polymers D1-D3 prepared in Comparative Examples 1-3 were added and stirred until completely dissolved. Then, 0.8g of thiourea was added, and the total weight was made up to 1kg with simulated brine. The pH was adjusted to 8, and the mixture was stirred evenly. The mixture was placed at 150℃ to observe gelation, and the dehydration rate was measured after 30 days at 150℃. The results are shown in Table 1.

[0144] Table 1

[0145] serial number Dehydration rate (%) after being placed at 150℃ for 30 days Example 1 4.2 Example 2 1.3 Example 4 3.4 Example 5 3.7 Example 6 9.6 Example 7 6.8 Example 8 5.9 Comparative Example 1 30.4 Comparative Example 2 35.2 Comparative Example 3 13.5

[0146] As can be seen from the results in Table 1, compared with Comparative Examples 1-3, the polyethyleneamine polymers prepared using Examples 1-2 and 4-8 of the present invention can be used as crosslinking agents to crosslink with polymers containing amide groups. The resulting gels have low dehydration rates after being placed in brine with a mineralization of 100,000 mg / L and a calcium and magnesium ion content of 2,000 mg / L at 150°C for 30 days. They can be used as plugging agents to seal high-permeability channels in high-temperature and high-salt oil reservoirs.

[0147] Application Example 2

[0148] This application example illustrates the use of polyethyleneamine polymers in the field of acid gas recovery.

[0149] ZSM-5 was washed with deionized water and ethanol to remove floating dust, soluble salts, and organic matter from the molecular sieve. It was then dried in an oven. The dried molecular sieve was added to a 1 mol / L solution of the polyethyleneamine polymer prepared in Examples 1-9 and Comparative Examples 1-3, stirred at room temperature for 2 hours, and ultrasonically impregnated for 2 hours. The molecular sieve was then filtered out and dried to obtain a molecular sieve coated with the polymer. The polymer-coated molecular sieve was then used for the capture of acidic gases.

[0150] CO2 adsorption was tested using a TGA 5500 thermogravimetric analyzer from Waters China Ltd. The specific steps were as follows: 0.1 g of molecular sieve coated with polyethyleneamine polymer was placed in a quartz crucible and pretreated for 2 h at 100℃ in a N2 atmosphere (flow rate 50 mL / min) to remove impurities. Afterward, the temperature was adjusted to 80℃, and the adsorption gas was switched to pure CO2 (flow rate 40 mL / min) for 30 min of adsorption testing. After adsorption, the temperature was increased to 135℃, and pure CO2 was used as the purge gas for 30 min of desorption testing. The CO2 adsorption capacity of the above material was obtained, as shown in Table 2.

[0151] Table 2

[0152] serial number <![CDATA[CO2 adsorption capacity (mmol / g)]]> Example 1 7.21 Example 2 6.93 Example 3 7.52 Example 4 5.95 Example 5 6.48 Example 6 5.32 Example 7 5.16 Example 8 5.54 Example 9 7.65 Comparative Example 1 4.02 Comparative Example 2 4.17 Comparative Example 3 4.82

[0153] As can be seen from the results in Table 2, compared with Comparative Examples 1-3, the polyethyleneamine polymers prepared using Examples 1-9 of the present invention have good adsorption capacity for CO2 due to the adjustable ratio of primary, secondary, and tertiary amines and the presence of high content of tertiary amines, and can be used as CO2 gas absorption materials.

[0154] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polyethyleneamine polymer, characterized in that, The polyethyleneamine polymer contains structural unit B as shown in formula (2), structural unit C as shown in formula (3), and optional structural unit A as shown in formula (1); the content of structural unit C is more than 5% by weight; Where R is methyl or ethyl.

2. The polyethyleneamine polymer according to claim 1, wherein, Based on the total weight of the polyvinylamine polymer, the content of structural unit A is 0-85% by weight, the content of structural unit B is 5-95% by weight, and the content of structural unit C is 5-90% by weight. Preferably, based on the total weight of the polyethyleneamine polymer, the content of structural unit A is 5-40% by weight, the content of structural unit B is 10-80% by weight, and the content of structural unit C is 20-85% by weight.

3. The polyethyleneamine polymer according to claim 1 or 2, wherein, The polyvinylamine polymers also contain structural units from at least one of 2-acrylamido-2-methylpropanesulfonic acid (sodium), N,N-dimethylacrylamide, acrylamide, N-vinylpyrrolidone, vinyl acetate, acrylonitrile, dimethylaminoethyl methacrylate, styrene sulfonic acid, vinyl sulfonic acid, acrylic acid, and their salts. And / or, the polyethyleneamine polymer does not contain quaternary ammonium salt structures; preferably, the content of quaternary ammonium salt structures is 0 based on the total weight of the polyethyleneamine polymer.

4. The polyethyleneamine polymer according to any one of claims 1-3, wherein, The number-average molecular weight of the polyethyleneamine polymer is 10,000 to 1,000,000 g / mol.

5. A method for preparing a polyethyleneamine polymer, characterized in that, The preparation method includes: reacting a polymer with an aldehyde compound by an addition reaction to obtain an amino alcohol; the polymer contains structural unit A as shown in formula (1) and / or structural unit B as shown in formula (2); The amino alcohol is dehydrated to form an imine and / or imine ion intermediate, and then a reductive amination reaction is carried out. Where R is methyl or ethyl.

6. The preparation method according to claim 5, wherein, The polymer is selected from copolymers or homopolymers formed by polymerization of monomers; the monomers include N-vinylformamide and / or N-methyl-N-vinylformamide; preferably, the monomers further include at least one of 2-acrylamido-2-methylpropanesulfonic acid (sodium), N,N-dimethylacrylamide, acrylamide, N-vinylpyrrolidone, vinyl acetate, acrylonitrile, dimethylaminoethyl methacrylate, styrene sulfonic acid, vinyl sulfonic acid, acrylic acid and its salts.

7. The preparation method according to claim 5 or 6, wherein, The aldehyde compound is selected from formaldehyde and / or acetaldehyde, preferably formaldehyde.

8. The preparation method according to any one of claims 5-7, wherein, The addition reaction is carried out at a temperature of 30-60℃, preferably 40-50℃; at a pH of 1-3, preferably 1-2; and for a time of 1-6h, preferably 2-5h.

9. The preparation method according to any one of claims 5-8, wherein, The reductive amination reaction is selected from catalytic hydrogenation reduction reaction, metal hydride reduction reaction, borane reduction reaction or formic acid reduction reaction.

10. The preparation method according to any one of claims 5-9, wherein, The reducing amination reaction is a formic acid reduction reaction, and the reaction temperature is 80-100℃, preferably 85-95℃; the reaction time is 4-11h, preferably 6-10h. Preferably, in the system of the reductive amination reaction, the molar ratio of aldehyde compound to formic acid is 1:0.8-8, more preferably 1:1-6.

11. A polyethyleneamine polymer prepared by any one of claims 5-10.

12. The use of polyethyleneamine polymers as described in any one of claims 1-4 and 11 in papermaking, water treatment, oilfield additives, or acid gas absorption.

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