An epoxy-based fatty amine modified amphiphilic block copolymer and a method of making the same

Abstract

The present application relates to a kind of epoxy group fatty amine modified amphiphilic block copolymer and its preparation method, the present application first adopts RAFT method to obtain amphiphilic block copolymer, then long-chain fatty amine and epoxy group amphiphilic block copolymer occur epoxy ring-opening reaction, obtain epoxy group fatty amine modified amphiphilic block copolymer.The epoxy modified amphiphilic block copolymer of the present application has certain viscosity reduction effect and the emulsion formed is better, can be used as thickened oil viscosity reducer, reduce the viscosity of special thickened oil.

Description

Technical Field

[0001] This invention relates to an epoxy-based fatty amine-modified amphiphilic block copolymer and its preparation method, belonging to the field of heavy oil viscosity reduction. Background Technology

[0002] Petroleum is a vital energy resource, but with the increasing consumption of oil and gas, conventional oil and gas reserves and production have been declining year by year. In this context, unconventional oil and gas resources, primarily heavy oil, are receiving increasing attention. Heavy oil generally has four main components: saturated components, aromatic components, gums, and asphaltenes. Asphaltenes have a complex structure, with molecules typically composed of large aromatic rings connected or surrounded by alkyl side chains, containing most of the heteroatoms present in crude oil (such as nitrogen, sulfur, and oxygen). The various interactions between these molecules lead to significant precipitation and aggregation characteristics of asphaltenes. Higher asphaltenes content results in higher crude oil viscosity; therefore, asphaltenes are a crucial factor affecting crude oil viscosity and are considered one of the most serious problems in oil extraction, transportation, and the production chain (such as extraction and refining). Thus, breaking the interactions between asphaltenes molecules and preventing their precipitation and aggregation has become a key challenge in heavy oil viscosity reduction technology in recent years.

[0003] Physical methods (such as heating) and chemical methods (such as adding chemical viscosity reducers) are commonly used to inhibit the aggregation of asphaltene. While physical methods (such as heating) are effective, they require a large amount of energy and are costly, while chemical methods are more energy-efficient and therefore have an advantage. Emulsification viscosity reduction technology utilizes functional molecules as viscosity reducers for heavy oils. This method is low-cost and highly effective, and is one of the current focuses of viscosity reduction research. However, the biggest problem with traditional emulsification viscosity reduction is the difficulty in controlling the stability of the emulsion. If the stability of the emulsion is too poor, an oil-water phase reversal phenomenon will occur during flow, resulting in a significant increase in viscosity; conversely, if the emulsion is too stable, it will affect subsequent demulsification and dehydration, leading to high post-processing costs.

[0004] Therefore, developing a viscosity reducer for heavy oil that is low in cost, requires small dosage, and has good emulsion stability has become an urgent problem to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an epoxy-based fatty amine-modified amphiphilic block copolymer and its preparation method. The invention first uses the RAFT method to obtain the amphiphilic block copolymer, and then introduces epoxy group modification into long-chain alkyl groups to obtain an epoxy-based fatty amine-modified amphiphilic block copolymer. This copolymer exhibits excellent viscosity-reducing effects and can be used as a viscosity reducer for heavy oils, lowering the viscosity of extra-heavy oils.

[0006] This invention is achieved through the following technical solution:

[0007] An epoxy-based fatty amine-modified amphiphilic block copolymer having the structure shown in Formula I:

[0008]

[0009] Where x = 80 - 220, y = 100 - 300, and n = 6 - 10.

[0010] According to a preferred embodiment of the present invention, x = 80-220, y = 100-300, and n = 6, 8, or 10.

[0011] This invention provides a method for preparing the epoxy-based fatty amine modified amphiphilic block copolymer described above, comprising the following steps:

[0012] (1) Mix monomer acrylamide (ACMO), compound a, initiator 1 and solvent A to react and obtain compound b;

[0013] (2) Compound b, glycidyl methacrylate (GMA) monomer, initiator and solvent B are mixed and reacted to obtain compound c;

[0014] (3) Compound c reacts with aliphatic amines in solvent C to obtain an epoxy-modified amphiphilic block copolymer.

[0015] According to a preferred embodiment of the present invention, the structure of compound a is shown in Formula II:

[0016]

[0017] According to a preferred embodiment of the present invention, in step (1), solvent A is 1,4-dioxane, chloroform, ethanol, methanol, acetone or toluene.

[0018] More preferably, solvent A is 1,4-dioxane.

[0019] According to a preferred embodiment of the present invention, in step (1), the mass-to-volume ratio of monomer acryloylmorpholine (ACMO) to solvent A is 0.1-1:1, g / mL.

[0020] According to a preferred embodiment of the present invention, in step (1), the initiator 1 is 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN), or azobisisoheptanenitrile (ABVN).

[0021] More preferably, the initiator 1 is 4,4'-azobis(4-cyanopentanoic acid) (ACVA).

[0022] According to a preferred embodiment of the present invention, in step (1), the amount of initiator 1 is 0.1-1% of the mass of monomer acryloylmorpholine (ACMO).

[0023] According to a preferred embodiment of the present invention, in step (1), the molar ratio of monomer acrylamide morpholine (ACMO) to compound a is 100:1-300:1.

[0024] More preferably, the molar ratio of monomer acrylamide (ACMO) to compound a is 200:1.

[0025] According to a preferred embodiment of the present invention, in step (1), the reaction temperature is 60-80°C, the reaction is carried out under inert gas protection, and the reaction time is 10-15 hours.

[0026] Further preferably, the reaction temperature is 70°C, the inert gas is preferably nitrogen or argon, and the reaction time is 12 hours.

[0027] According to a preferred embodiment of the present invention, in step (1), the post-treatment method of the reaction solution obtained from the reaction can be carried out according to the prior art. Preferably, after the reaction is completed, the solution is precipitated three times with anhydrous diethyl ether and then vacuum dried to obtain a light red solid.

[0028] According to a preferred embodiment of the present invention, the structure of compound b is shown in Formula III:

[0029]

[0030] Where x = 100 - 300

[0031] According to a preferred embodiment of the present invention, in step (2), the solvent B is 1,4-dioxane, dimethyl sulfoxide (DMSO), methanol or ethanol.

[0032] More preferably, the solvent B is 1,4-dioxane.

[0033] According to a preferred embodiment of the present invention, in step (2), the mass-to-volume ratio of compound b to solvent B is 0.1-1:1, g / mL.

[0034] According to a preferred embodiment of the present invention, in step (2), the initiator 2 is 4,4'-azobis(4-cyanopentanoic acid) (ACVA), azobisisobutyronitrile (AIBN), or azobisisoheptanenitrile (ABVN).

[0035] More preferably, the initiator 2 is 4,4'-azobis(4-cyanopentanoic acid) (ACVA).

[0036] According to a preferred embodiment of the present invention, in step (2), the amount of initiator 2 is 0.1-1% of the mass of compound b.

[0037] According to a preferred embodiment of the present invention, in step (2), the molar ratio of glycidyl methacrylate (GMA) to compound b is 100:1-300:1.

[0038] According to a preferred embodiment of the present invention, in step (2), the reaction temperature is 60-80°C, the reaction is carried out under inert gas protection, and the reaction time is 12-24h.

[0039] More preferably, in step (2), the reaction temperature is 70°C, the inert gas is nitrogen or argon, and the reaction time is 18h.

[0040] According to a preferred embodiment of the present invention, in step (2), the post-treatment method of the reaction solution obtained from the reaction can be carried out according to the prior art. Preferably: after the reaction is completed, the polymer solution is transferred to a semi-permeable membrane and purified by dialyzing in deionized water for 3 days. The dialysate is then freeze-dried to obtain compound b.

[0041] According to a preferred embodiment of the present invention, the structure of compound c is shown in formula IV:

[0042]

[0043] Where x = 100 - 300, y = 300 - 100.

[0044] According to a preferred embodiment of the present invention, in step (3), the fatty amine is one or a combination of two or more of n-hexylamine, octylamine, or decylamine.

[0045] According to a preferred embodiment of the present invention, in step (3), the molar ratio of the fatty amine to compound c is 1-10:1.

[0046] According to a preferred embodiment of the present invention, in step (3), the reaction temperature of the fatty amine with compound c is 30-70°C, and the reaction time is 12-28h.

[0047] More preferably, the reaction temperature of the fatty amine with compound c is 60°C and the reaction time is 24 h.

[0048] According to a preferred embodiment of the present invention, in step (3), the solvent C is dimethyl sulfoxide (DMSO).

[0049] According to a preferred embodiment of the present invention, in step (3), the mass-to-volume ratio of compound c to solvent C is 1:(10-30), g / mL.

[0050] The synthetic route of the epoxy-based fatty amine modified amphiphilic block copolymer of the present invention is as follows:

[0051]

[0052] The above-mentioned epoxy-based fatty amine modified amphiphilic block copolymer or the epoxy-based fatty amine modified amphiphilic block copolymer prepared by the above preparation method is used as a viscosity reducer for heavy oil to reduce the viscosity of heavy oil, with an addition amount of 800-1500 mg / L.

[0053] The technical features and beneficial effects of this invention are as follows:

[0054] 1. This invention first uses the RAFT method to obtain an amphiphilic block copolymer, and then reacts a long-chain aliphatic amine with the epoxy-based amphiphilic block copolymer via an epoxy ring-opening reaction to obtain an epoxy-based aliphatic amine-modified amphiphilic block copolymer. RAFT polymerization is considered one of the best methods for preparing multi-block copolymers and complex polymer structures due to its reactivity and controllability throughout the polymerization process. The RAFT reagent plays a crucial role in the entire RAFT polymerization process. This invention selects compound a, a RAFT reagent particularly suitable for methacrylate and acryloylmorpholine monomers, which can effectively polymerize both monomers under mild reaction conditions and good controllability.

[0055] 2. Acryloylmorpholine, as a functional monomer of this invention, possesses excellent amphiphilic properties. Its unique N,O heterocyclic structure can effectively interact with the asphaltenes of heavy oil, disrupting hydrogen bonds and π-π stacking to achieve a viscosity-reducing effect. Glycidyl methacrylate (GMA) homopolymers exhibit certain hydrophobic properties and possess a unique epoxy structure, allowing for ring-opening reactions with amino, carboxyl, and hydroxyl groups under different conditions, thus enabling further modification. This invention uses acryloylmorpholine and glycidyl methacrylate as monomers, modified with fatty amines to form an amphiphilic surfactant. Through the regulation of polar and hydrophobic groups, it can dissociate with heavy oil, significantly reducing the viscosity of the heavy oil.

[0056] 3. The present invention uses monomers with specific structures (such as glycidyl methacrylate), combined with specific monomer dosages and preparation methods to prepare polymers with the structure and properties of the present invention. Each group works together to achieve the excellent effects of the present invention. Attached Figure Description

[0057] Figure 1 The NMR spectra of the block copolymer PACMO-b-PGMA and the final product of Example 1 are shown; a is the block copolymer PACMO-b-PGMA, and b is the final product.

[0058] Figure 2 The infrared spectra of the block copolymer PACMO-b-PGMA and the final product of Example 1 are shown; a is the block copolymer PACMO-b-PGMA, and b is the final product.

[0059] Figure 3 The graphs show the stability analysis of the final product of Example 1 and Comparative Example 1, where a represents Comparative Example 1 and b represents Example 1. Detailed Implementation

[0060] The present invention will be further described below with reference to specific embodiments, but is not limited thereto.

[0061] Furthermore, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods; and unless otherwise specified, the reagents, materials and equipment are all commercially available.

[0062] Example 1

[0063] A method for preparing an epoxy-based fatty amine-modified amphiphilic block copolymer includes the following steps:

[0064] (1) In a 5 mL reaction flask, 0.56 g of monomer ACMO, 0.0028 g of initiator ACVA, and 0.0112 g of compound a (RAFT chain transfer agent II) were added sequentially and dissolved in 2 mL of 1,4-dioxane. The mixture was evacuated and purged with nitrogen three times, and stirred at 70 °C for 12 h. The reaction was then terminated by rapid cooling. After the reaction was completed, the mixture was precipitated three times with anhydrous diethyl ether and dried under vacuum to obtain a pale red solid (PACMO).

[0065] (2) Add 0.571g of PACMO synthesized in step (1), 0.568g of monomer GMA, and 0.0028g of ACVA to a 5mL reaction flask, dissolve them in 2mL of 1,4-dioxane, evacuate and purge with nitrogen three times, and stir at 70℃ for 18h. Then, cool the temperature rapidly to terminate the reaction. After the reaction is complete, transfer the polymer solution to a semipermeable membrane and dialyze it in deionized water for 3 days. After the dialysate is freeze-dried, the block copolymer PACMO-b-PGMA is obtained.

[0066] (3) The block copolymer PACMO-b-PGMA was dissolved in DMSO, and n-hexylamine with a molar ratio of 1:10 to the GMA segment contained in the polymer was added. The reaction was carried out at 60°C for 24 hours under nitrogen protection. After the reaction was completed, the polymer solution was transferred to a semipermeable membrane and purified by dialyzing with deionized water for 3 days to remove impurities. The dialysate was freeze-dried to obtain the epoxy fatty amine modified amphiphilic block copolymer PA-HA.

[0067] 1. Nuclear magnetic resonance characterization

[0068] To determine whether the synthesized product matched the designed product structure, the block copolymer PACMO-b-PGMA from Example 1 and the final product structure were determined using a Bruker Avance 400MHz NMR spectrometer. The results are as follows: Figure 1As shown in the figure, 'a' represents the block copolymer PACMO-b-PGMA. The peaks at δ: 1.0-1.5 ppm represent protons on the RAFT chain transfer agent backbone, δ: 3.0 ppm represents a proton peak on the epoxy ring, and δ: 3.2-3.7 ppm represents a proton peak on the morpholine ring. Simultaneously, the disappearance of the double bond peaks in the olefin indicates that the monomers have been removed from the polymer. This demonstrates that both ACMO and GMA monomers have been introduced into the polymer.

[0069] Where b is the final product, after modification by introducing an alkyl chain, through... 1 The 1H NMR spectrum shows the addition of a proton peak at δ:0.75 ppm on the terminal methyl group of the long-chain alkyl group, and a proton peak on the methylene group of the alkyl chain appearing at δ:1.10-1.25 ppm, proving that a long-chain alkyl group has been successfully introduced into the polymer. 1 1H NMR spectral analysis indicates that the polymer has been modified.

[0070] 2. Infrared characterization

[0071] The structures of the block copolymer PACMO-b-PGMA and the final product of Example 1 were determined using a Tensor 27 Fourier transform infrared spectrometer from Burker, Germany. The results are as follows: Figure 2 As shown. Where a. 3100cm -1 The absence of a -C=C- absorption peak near the 1645 cm⁻¹ indicates the absence of a monomer. -1 The peak value for the stretching vibration of C=O in PACMO is 2856-2965 cm⁻¹. -1 The peak at 1730 cm⁻¹ represents the symmetric stretching vibration of the methylene group in PACMO, while the peak at 1730 cm⁻¹ represents the peak of the methylene group in PACMO. -1 The peak of the C=O stretching vibration of PGMA is located at 757 cm⁻¹. -1 The peaks are characteristic of the three-membered ring in PGMA, indicating that the monomers have been incorporated into the polymer. Compared to PACMO-b-PGMA, the FT-IR spectra (b) of polymers with different aliphatic amines show peaks at 3500 cm⁻¹. -1 The area and intensity of the polymer characteristic peaks changed after left and right modifications, and also changed at 3467, 3500, and 3521 cm⁻¹. -1 The NH stretching vibration peak was added at 1280-1100 cm⁻¹. -1 The intensity of the CO stretching vibration peak within the specified range decreased, indicating that the polymer has been successfully modified. Figure 1 and Figure 2 This indicates that the target product has been synthesized.

[0072] Example 2

[0073] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is described in Example 1, except that the amount of compound a RAFT chain transfer agent is 0.286 g, and the other steps and conditions are the same as in Example 1.

[0074] Example 3

[0075] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is described in Example 1, except that the amount of compound a RAFT chain transfer agent is 0.857 g, and the other steps and conditions are the same as in Example 1.

[0076] Example 4

[0077] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is described in Example 1, except that the amount of compound a RAFT chain transfer agent is 1.142 g, and the other steps and conditions are the same as in Example 1.

[0078] Example 5

[0079] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is described in Example 1, except that the amount of GMA used is 0.852 g, and the other steps and conditions are the same as in Example 1.

[0080] Example 6

[0081] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is described in Example 1, except that the amount of n-hexylamine used is 0.06 g, and the other steps and conditions are the same as in Example 1.

[0082] Example 7

[0083] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is as described in Example 1, except that the amount of n-hexylamine used is 0.03 g, and the other steps and conditions are the same as in Example 1.

[0084] Example 8

[0085] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is as described in Example 1, except that the fatty amine used is octylamine, and the amount used is 0.05g. The other steps and conditions are the same as in Example 1.

[0086] Example 9

[0087] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is as described in Example 1, except that the fatty amine used is decylamine, and the amount used is 0.05g. The other steps and conditions are the same as in Example 1.

[0088] Comparative Example 1

[0089] A method for preparing an epoxy-based fatty amine modified amphiphilic block copolymer is as described in Example 1, except that step (3) fatty amine modification is not performed, while other steps and conditions are the same as in Example 1, to obtain a block copolymer of type IV.

[0090] Comparative Example 2

[0091] A method for preparing an epoxy-based fatty amine-modified amphiphilic block copolymer is described in Example 1, except that the RAFT chain transfer agent is replaced with 4-cyano-4-(ethylthioalkylthiocarbonyl)thioalkylpentanoic acid, while the other steps and conditions are the same as in Example 1. However, the monomer conversion rate is low, and the copolymer synthesis is difficult.

[0092] Test case

[0093] Viscosity reduction test

[0094] Examples and Comparative Example 1 were prepared into aqueous solutions with a concentration of 1000 ppm. They were mixed in a ratio of 7:3 for heavy oil to polymer aqueous solution and heated at 50°C for 1 hour to ensure thorough mixing. The viscosity of the oil-water mixture at 50°C was then measured using a viscometer. The viscosity of the crude oil was 28530 mPa·s. The test results are shown in Table 1.

[0095] Table 1. Viscosity comparison of the products from the examples and comparative examples.

[0096]

[0097]

[0098] Stability analysis

[0099] The stability of the heavy oil emulsion formed after polymer emulsification and viscosity reduction was determined using a Turbiscan Lab stability analyzer. The TSI (Stability Kinetic Index) was then analyzed using software to reflect the emulsion's instability. The test results are shown below. Figure 3 As shown. Comparative Example 1(a) before modification and Example 1(b) with the best viscosity-reducing effect after modification were analyzed. The results showed that the TSI value of the polymer-based heavy oil emulsion before modification gradually increased, with a faster rate of change in the early stage followed by a more stable rate, but overall it remained unstable and the emulsion was prone to demulsification. In contrast, the overall TSI index of Example 1 after modification was more stable and less than 1, indicating that the oil-water emulsion was more stable with only a small amount of dehydration and demulsification. This demonstrates that the introduction of short alkyl chains can improve the stability of the O / W emulsion formed by the interaction between the viscosity reducer and heavy oil to a certain extent.

Claims

1. A method for preparing an epoxy-based fatty amine-modified amphiphilic block copolymer, comprising the following steps: (1) The monomer acryloylmorpholine (ACMO), compound a, initiator 1 and solvent A are mixed and reacted to obtain compound b; The structure of compound a is shown in Formula II below: ， The structure of the obtained compound b is shown in Formula III below: Where x = 80 - 220, (2) Compound b, glycidyl methacrylate (GMA) monomer, initiator 2 and solvent B are mixed and reacted to obtain compound c; the solvent B is 1,4-dioxane, dimethyl sulfoxide (DMSO), methanol or ethanol, and the mass-volume ratio of compound b to solvent B is (0.1-1):1 g / mL; the initiator 2 is 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN) or azobisisoheptanenitrile (ABVN), and the amount of initiator 2 is 0.1-1% of the mass of compound b; The structure of compound c is shown in formula IV below: Where x = 80 - 220, y = 300 - 100, (3) Compound c reacts with aliphatic amines in solvent C to obtain an epoxy-modified amphiphilic block copolymer, which has the structure shown in Formula I: Where x = 80 - 220, y = 100 - 300, and n = 6 - 10.

2. The preparation method according to claim 1, characterized in that, In step (1), solvent A is 1,4-dioxane, chloroform, ethanol, methanol, acetone or toluene, and the mass-volume ratio of monomer acrylomorpholine (ACMO) to solvent A is (0.1-1):1 g / mL. Initiator 1 is 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN) or azobisisoheptanenitrile (ABVN), and the amount of initiator 1 is 0.1-1% of the mass of monomer acrylomorpholine (ACMO).

3. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of monomer acrylamide (ACMO) to compound a is 100:1-300:1, the reaction temperature is 60-80℃, the reaction is carried out under inert gas protection, and the reaction time is 10-15h. After the reaction is completed in step (1), the solid is precipitated three times with anhydrous diethyl ether and dried under vacuum to obtain a light red solid.

4. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of glycidyl methacrylate (GMA) to compound b is 100:1-300:1, the reaction temperature is 60-80℃, the reaction is carried out under inert gas protection, and the reaction time is 12-24h. In step (2), after the reaction is completed, the polymer solution is transferred to a semi-permeable membrane and purified by dialyzing in deionized water for 3 days. After the dialysate is freeze-dried, compound b is obtained.

5. The preparation method according to claim 1, characterized in that, In step (3), the fatty amine is one or more of hexylamine, octylamine or decylamine, and the molar ratio of the fatty amine to compound c is 1-10:

1.

6. The preparation method according to claim 2, characterized in that, In step (3), the reaction temperature of the fatty amine with compound c is 30-70℃ and the reaction time is 12-28h. In step (3), the solvent C is dimethyl sulfoxide (DMSO) and the mass-volume ratio of compound c to solvent C is 1:(10-30)g / mL.

7. The application of the epoxy-based fatty amine modified amphiphilic block copolymer prepared by any of the preparation methods described in claims 1-6, as a viscosity reducer for heavy oil, wherein the addition amount is 800-1500 mg / L.

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