Lignin alcohol ether, emulsifying system composition containing lignin alcohol ether, and preparation method and application of emulsifying system composition

Abstract

The invention discloses lignin alcohol ether, an emulsification system composition containing the lignin alcohol ether as well as a preparation method and application of the emulsification system composition. The lignin alcohol ether disclosed by the invention is obtained by sequentially reacting phenolated modified lignin with raw materials including epoxy haloalkane and polyhydric alcohol. The emulsification system composition comprises span and lignin alcohol ether. The emulsion system composition containing lignin alcohol ether can be applied to the inverse emulsion synthesis process of acrylamide polymers and can well emulsify and stabilize a polymerization reaction system, and the obtained emulsion product has the characteristics of low gel content, higher molecular weight, better long-term storage stability, lower residual monomer content and higher dissolution rate. According to the emulsification system, the production cost of the acrylamide polymer emulsion is reduced, the performance and economical efficiency requirements of site construction can be met, and the practicability is relatively high.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsifiers for synthesizing acrylamide polymers by inverse emulsion, and further relates to lignin alcohol ethers, emulsifying system compositions containing lignin alcohol ethers, and their preparation methods and applications. Background Art

[0002] Inverse emulsion polymerization refers to a process in which an aqueous monomer solution and an organic oil phase form a water-in-oil emulsion under the emulsification of a surfactant, and then a water-in-oil polymer is synthesized under the action of an initiator. Among them, emulsifiers belong to surfactants, which are substances that can form micelles and play an important role in emulsion polymerization. The types and amounts of emulsifiers and the selection of the emulsifying system directly affect the stability of the inverse emulsion and are necessary conditions for successful polymerization reactions.

[0003] The polyacrylamide structural unit contains an amide group, which is easy to form intramolecular and intermolecular hydrogen bonds, making it have good thickening, flocculation, and drag reduction effects. Therefore, it has a wide range of applications in the fields of oil exploitation, water treatment, papermaking, etc. At present, there are many methods for synthesizing polyacrylamide, such as aqueous solution polymerization, bulk polymerization, suspension polymerization, etc. Among them, inverse emulsion polymerization has the advantages of high polymerization rate, high molecular weight of the product, and rapid solubility, and has become a research hotspot.

[0004] Natural lignin is a natural polyaromatic macromolecular compound composed of hydrophobic non-polar groups with a phenylpropane skeleton and hydrophilic polar groups such as phenolic groups. The main connection methods between the structural main bodies of lignin are ether bonds and carbon-carbon bonds. These two types of bonds have small molecular polarity and high bond energy and are difficult to react. Moreover, the methoxy content is high, the hydroxyl content is low, and the steric hindrance on the benzene ring is large, resulting in significantly insufficient reaction activity. For commercially available industrial by-product lignin, due to the condensation reaction after chemical treatment, its reaction sites are even fewer. Therefore, although lignin has certain surface activity, its direct use as an emulsifier has unsatisfactory effects due to its poor performance, and its application market is greatly restricted. However, using lignin as a raw material for preparing emulsifiers can turn waste into treasure and significantly reduce the cost of emulsifiers.

[0005] At the same time, the reserves of lignin in nature are second only to cellulose and are the second largest natural organic matter. Industrial lignin is rich in sources and low in price and can be used as a raw material for producing oilfield chemicals. With the rise in the price of petrochemical raw materials and the improvement of environmental protection requirements, green chemicals using low-cost natural renewable resources such as lignin as raw materials have become an international hot research direction.

[0006] Therefore, if lignin can be modified to prepare an emulsifier for synthesizing acrylamide polymers by inverse emulsion, it will have important significance. Summary of the Invention

[0007] To solve the problems in the existing technology, the present invention provides lignin alcohol ether, an emulsifying system composition containing lignin alcohol ether, and its preparation method and application. The emulsifying system composition containing lignin alcohol ether in the present invention consists of lignin alcohol ether and Span surfactants. Among them, lignin alcohol ether is obtained by first modifying lignin to obtain phenolic modified lignin, and then reacting with epoxy haloalkanes (such as epichlorohydrin) and polyols.

[0008] The emulsifying system composition containing lignin alcohol ether can be applied to the inverse emulsion synthesis process of acrylamide polymers, and can well emulsify and stabilize the polymerization reaction system. This emulsifying system expands the raw material sources of surfactants, all of which belong to natural surfactants, have high safety, and are biodegradable. When the emulsifying system composition containing lignin alcohol ether is used in the process of inverse emulsion synthesis of acrylamide polymers, the obtained emulsion products have the characteristics of low gel content, higher molecular weight, better long-term storage stability, lower residual monomer content, and faster dissolution rate. This emulsifying system reduces the production cost of acrylamide polymer emulsions, can meet the performance and economic requirements of on-site construction, and has high practicability. And after the acrylamide polymer is injected underground, the phenylpropane structure of lignin can well emulsify crude oil, which is beneficial to the emulsification and production of crude oil.

[0009] One of the purposes of the present invention is to provide a lignin alcohol ether, which is obtained by sequentially reacting raw materials including phenolic modified lignin, epoxy haloalkanes, and polyols. Among them, the phenolic modified lignin is selected from phenolic modified lignin modified by alkali catalysis.

[0010] Another purpose of the present invention is to provide a preparation method of lignin alcohol ether, which includes the following steps:

[0011] Step (A): Add phenolic modified lignin to water, adjust the pH, and after the phenolic modified lignin is completely dissolved, add epoxy haloalkane for heating reaction to obtain lignin ether; among them, the phenolic modified lignin is selected from phenolic modified lignin modified by alkali catalysis;

[0012] Step (B): Carry out a contact reaction between lignin ether and polyol in water to obtain lignin alcohol ether;

[0013] It is preferably used to prepare the lignin alcohol ether described in one of the purposes of the present invention.

[0014] In the preparation method of the lignin alcohol ether described in the present invention, preferably,

[0015] In step (A),

[0016] the epoxy haloalkane is selected from epichlorohydrin; and / or,

[0017] adjust the pH value to 12.5 - 13.5; and / or,

[0018] Based on the total mass of water, phenolic-modified lignin, and epoxy haloalkane added in this step being 100%,

[0019] the addition amount of phenolic-modified lignin is 40 - 60 wt%;

[0020] the addition amount of epichlorohydrin is 2 - 5 wt%; the rest is water;

[0021] the temperature of the heating reaction is 60 - 70 °C; and / or,

[0022] the time of the heating reaction is 2 - 8 h.

[0023] In the method for preparing lignin alcohol ether described in the present invention, preferably,

[0024] in step (B),

[0025] the polyol is selected from at least one of glycerol and pentaerythritol; and / or,

[0026] Based on the total mass of water, lignin ether, and polyol added in this step being 100%,

[0027] the addition amount of lignin ether is 40 - 60 wt%;

[0028] the addition amount of polyol is 1 - 3 wt%; the rest is water;

[0029] the temperature of the contact reaction is 30 - 45 °C; and / or,

[0030] the time of the contact reaction is 1 - 4 h.

[0031] In the method for preparing lignin alcohol ether described in the present invention, preferably,

[0032] The method for preparing phenolic-modified lignin is as follows:

[0033] After the raw materials including lignin, phenolic modifier, and alkaline catalyst are subjected to a contact reaction in water, optionally adjust the pH to obtain phenolic-modified lignin;

[0034] Preferably,

[0035] the lignin is selected from at least one of alkali lignin and enzymatic hydrolysis lignin; and / or,

[0036] the phenolic modifier is selected from at least one of phenol and hydroquinone; and / or,

[0037] the alkaline catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, and ammonia water; and / or,

[0038] Based on the total mass of lignin, phenolic modifier, alkaline catalyst and water added in this step being 100%,

[0039] the addition amount of lignin is 10 - 15 wt%;

[0040] the mass ratio of the phenolic modifier to the lignin is 0.2 - 0.4:1;

[0041] the mass ratio of the alkaline catalyst to the lignin is 0.12 - 0.3:1; and / or,

[0042] the temperature of the contact reaction is 70 - 85 °C; and / or,

[0043] the contact reaction time is 0.5 - 2 h; and / or,

[0044] adjust the pH to 2 - 3.

[0045] The third object of the present invention is to provide an emulsifying system composition containing lignin alcohol ether, and the emulsifying system composition includes span and lignin alcohol ether;

[0046] The lignin alcohol ether is the lignin alcohol ether described in one of the objects of the present invention or the lignin alcohol ether prepared by the preparation method described in any one of the second objects of the present invention.

[0047] In the emulsifying system composition containing lignin alcohol ether of the present invention, preferably,

[0048] in the emulsifying system composition,

[0049] the content of span is 70 - 90 wt%;

[0050] the content of lignin alcohol ether is 10 - 30 wt%;

[0051] Preferably,

[0052] the content of span is 75 - 80 wt%;

[0053] the content of lignin alcohol ether is 20 - 25 wt%.

[0054] In the emulsifying system composition containing lignin alcohol ether of the present invention, preferably,

[0055] the span is selected from at least one of span 60, span 80, and span 83.

[0056] The fourth object of the present invention is to provide a preparation method of the emulsifying system composition containing lignin alcohol ether described in any one of the third objects of the present invention, including the following steps:

[0057] Mix span and lignin alcohol ether evenly to obtain the emulsifying system composition.

[0058] A fifth object of the present invention is to provide an emulsion containing an acrylamide polymer, which is prepared by inverse emulsion synthesis using raw materials including an emulsifying system composition containing lignin alcohol ether, monomers, initiators, and chelating agents described in any one of the third objects of the present invention to obtain an acrylamide polymer emulsion.

[0059] A sixth object of the present invention is to provide a method for preparing an emulsion containing an acrylamide polymer.

[0060] Form an oil solution by mixing the emulsifying system composition with an organic solvent;

[0061] Mix a vinyl monomer, optionally a sulfonic acid monomer, a chelating agent, a part of the initiator, and water to form an aqueous solution;

[0062] Mix the oil solution with the aqueous solution to form a water-in-oil emulsion;

[0063] After deoxygenating the water-in-oil emulsion, add the remaining initiator to carry out a polymerization reaction to obtain an emulsion containing an acrylamide polymer;

[0064] The emulsifying system composition is selected from the emulsifying system compositions described in any one of the third objects of the present invention;

[0065] It is preferably used for the preparation of the emulsion containing an acrylamide polymer described in any one of the fifth objects of the present invention.

[0066] In the method for preparing the emulsion containing an acrylamide polymer described in the present invention, preferably,

[0067] The organic solvent is selected from at least one of white oil and kerosene; and / or,

[0068] The mass ratio of the organic solvent to the emulsifying system composition is 1:0.05 - 0.2; and / or,

[0069] The vinyl monomer is selected from at least one of acrylamide, acrylic acid, and N-isopropylacrylamide; and / or,

[0070] When a sulfonic acid monomer is contained, the sulfonic acid monomer is selected from at least one of 2-acrylamido-2-methylpropanesulfonic acid and 2-acryloyloxy-2-methylpropanesulfonic acid; and / or,

[0071] The chelating agent is selected from at least one of disodium ethylenediaminetetraacetate and trisodium ethylenediaminetetraacetate; and / or,

[0072] The initiator is selected from at least one of redox initiators (such as ammonium persulfate - sodium bisulfite) and azo initiators (such as VA-044);

[0073] In the aqueous solution,

[0074] The content of the vinyl monomer is 40 - 50 wt%.

[0075] The content of the sulfonic acid monomer is 0 - 50 wt%.

[0076] The content of the chelating agent is 0.01 - 0.1 wt%.

[0077] The content of a part of the initiator added is 0.01 - 0.1 wt%; the rest is water, and / or,

[0078] The mass ratio of the part of the initiator to the remaining initiator is 1 - 4:1; and / or,

[0079] The mass ratio of the aqueous solution to the oil solution is 1 - 3:1; and / or,

[0080] The temperature of the polymerization reaction does not exceed 40°C; preferably, the temperature of the polymerization reaction does not exceed 35°C; and / or,

[0081] The time of the polymerization reaction is 2 - 6 h.

[0082] The seventh object of the present invention is to provide an application of the emulsion containing an acrylamide polymer described in the fifth object of the present invention or the emulsion containing an acrylamide polymer prepared by the method described in any one of the sixth objects of the present invention in oil exploitation.

[0083] In the present invention, the lignin, the catalyst and the phenolic modifier can all be commercially obtained;

[0084] In the present invention, the method for adjusting the pH is a method commonly used in the art. Preferably, the pH is adjusted by adding an acidic substance or a basic substance. The acidic substance can be at least one of hydrochloric acid, sulfuric acid, acetic acid, and oxalic acid; the basic substance is sodium hydroxide, potassium hydroxide, etc.

[0085] In the present invention, the purification method can be a conventional purification method in the art. For example, the mixture solution obtained after the reaction is centrifuged, then washed repeatedly, and finally dried in vacuo.

[0086] In the present invention, there is no particular limitation on the mixing of the lignin alcohol ether and the Span surfactant, and it can be mixed evenly.

[0087] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In the following text, in principle, various technical solutions can be combined with each other to obtain new technical solutions, which should also be regarded as specifically disclosed herein.

[0088] Compared with the prior art, the present invention includes the following advantages:

[0089] The present invention provides an emulsifying system containing lignin alcohol ether, its preparation method and application. The emulsifying system is composed of lignin alcohol ether and Span surfactants. Among them, the lignin alcohol ether is obtained by first phenolicating lignin and then reacting with epichlorohydrin and polyols. The inventors of the present invention unexpectedly found in the research that by alkaline phenolic modification of lignin, the phenolic hydroxyl content of lignin can be greatly increased, the reaction activity of lignin can be greatly improved, and the conversion rate of lignin in subsequent modification can be enhanced. Moreover, there is a synergistic effect between lignin alcohol ether and Span, forming a complementarity in space and activity, forming an emulsifying system containing bio-based polyether (i.e., an emulsifying system containing lignin alcohol ether), and improving the stability and efficiency of the emulsifying system.

[0090] When the emulsifying system containing lignin alcohol ether is used in the process of inverse emulsion synthesis of acrylamide polymers, the obtained emulsion product has the characteristics of low gel content, higher molecular weight, better long-term storage stability, lower residual monomer content, and faster dissolution rate.

[0091] The present invention also finds that there is a synergistic effect when lignin alcohol ether and a specific Span surfactant are used as emulsifiers, and has a good emulsifying effect. Detailed implementation manners

[0092] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only for further illustration of the present invention and cannot be understood as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the content of the present invention still fall within the protection scope of the present invention.

[0093] In addition, it should be noted that in the following detailed implementation manners, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0094] In addition, any combination can be made among various different embodiments of the present invention as long as it does not violate the idea of the present invention. The technical solutions thus formed are part of the original public content of this specification and also fall within the protection scope of the present invention.

[0095] Source of raw materials:

[0096] The enzymatically hydrolyzed lignin was purchased from Shandong Longli Biotechnology Co., Ltd., and the effective lignin content was 94.8 wt%.

[0097] The alkali lignin was purchased from J&K Scientific Ltd.

[0098] Other raw materials of the present invention are all conventional commercially available products.

[0099] Testing method:

[0100] Molecular weight test:

[0101] The intrinsic viscosity was determined according to the method for determining the intrinsic viscosity of polyacrylamide in GB 12005.1 - 1989, and the molecular weight was calculated based on the intrinsic viscosity.

[0102] Determination of residual monomer content:

[0103] The residual monomer content was determined according to the method for determining the residual acrylamide content in polyacrylamide in GB 12005.3 - 1989.

[0104] Testing method for dissolution time:

[0105] The viscosity was measured every minute, and the time when the viscosity reached 80% of the final viscosity was taken as the dissolution time.

[0106] Example 1

[0107] (1) Preparation of highly active lignin: 80.2 g of water and 2.4 g of catalyst NaOH were added into a three - necked flask equipped with a stirrer and a condenser; the temperature of the system was raised to the set temperature of 80 °C, and 13.6 g of enzymatically hydrolyzed lignin and 3.8 g of phenol were successively added under stirring, then continued stirring, heating and refluxing for 1.5 h; after the reaction ended, hydrochloric acid was added to adjust the pH to 3.0 (the purpose of adjusting the pH in this step was to precipitate the product), so that the product precipitated, and the product, highly active lignin (i.e., phenolic - modified lignin), was obtained through centrifugal separation, washing and vacuum drying.

[0108] (2) Preparation of lignin alcohol ether: Dissolve 48.0 g of high-activity lignin in 48.4 g of water, adjust the pH value of the system to 13.2 with sodium hydroxide, and stir until completely dissolved; heat the system to 68 °C, add 3.6 g of epichlorohydrin, stop the reaction after reacting for 6 h, cool the system to room temperature, separate, wash, and dry to obtain the etherification product (i.e., lignin ether); take 5 g of the etherification product and add it to 4.84 g of water, heat the system to 40 °C, add 0.16 g of glycerol, stop the reaction after reacting for 2.5 h, cool the system to room temperature, separate and purify to obtain lignin alcohol ether.

[0109] (3) Mix 2.2 g of lignin alcohol ether and 7.8 g of Span 60 evenly to obtain an emulsifier containing lignin alcohol ether.

[0110] (4) Carry out inverse emulsion synthesis on the above emulsifier (emulsion system composition) to obtain an emulsion containing acrylamide polymer, specifically:

[0111] Form an oil solution by mixing 10 g of the emulsifier containing lignin alcohol ether with 80 g of white oil; dissolve 80 g of acrylamide and 20 g of 2-acrylamido-2-methylpropanesulfonic acid sodium in 70 g of water, adjust the pH to 7, then add 0.02 g of disodium ethylenediaminetetraacetate, 0.015 g of VA-044, and 0.01 g of ammonium persulfate and dissolve completely to form an aqueous solution; mix the oil solution and the aqueous solution, and emulsify at high speed to form a water-in-oil emulsion; after deoxygenating the water-in-oil emulsion, slowly drop in 1 g of 1 wt% sodium bisulfite aqueous solution to carry out a polymerization reaction on the water-in-oil emulsion, control the reaction temperature not to exceed 35 °C, and stop the reaction when the system no longer continues to heat up.

[0112] When the emulsifier containing lignin alcohol ether is used for inverse emulsion synthesis of acrylamide polymer, the gel content of the obtained emulsion product is 0.4 wt%, the dissolution time is 1 min, it stratifies after storing at room temperature for 160 days, the viscosity-average molecular weight of the polymer is 18.5 million, and the residual monomer content is 0.03 wt%.

[0113] Example 2

[0114] (1) Preparation of high-activity lignin: Add 80.2 g of water and 1.8 g of catalyst KOH to a three-necked flask equipped with a stirrer and a condenser; heat the system to the set temperature of 70 °C, and sequentially add 15 g of alkali lignin and 3.0 g of phenol under stirring, continue stirring, heat and reflux for 0.5 h; after the reaction ends, adjust the pH to 2.5 with hydrochloric acid to precipitate the product, and obtain the product high-activity lignin through centrifugal separation, washing, and vacuum drying.

[0115] (2) Preparation of lignin alcohol ether: Dissolve 48.0 g of high-activity lignin in 48.4 g of water, add sodium hydroxide to adjust the pH value of the system to 13.2, and stir until completely dissolved; heat the system to 68 °C, add 3.6 g of epichlorohydrin, stop the reaction after reacting for 6 h, cool the system to room temperature, separate, wash, and dry to obtain the etherification product; take 5 g of the etherification product and add it to 4.84 g of water, heat the system to 40 °C, add 0.16 g of glycerol, stop the reaction after reacting for 2.5 h, cool the system to room temperature, separate and purify to obtain lignin alcohol ether.

[0116] (3) Mix 2.2 g of lignin alcohol ether and 7.8 g of Span 83 evenly to obtain an emulsifier containing lignin alcohol ether.

[0117] Use the emulsifier containing lignin alcohol ether for the inverse emulsion synthesis of acrylamide polymers by the same method as in Example 1. The gel content of the obtained emulsion product is 0.7 wt%, the dissolution time is 1 min, it stratifies after storing at room temperature for 150 days, the viscosity-average molecular weight of the polymer is 17 million, and the residual monomer content is 0.06 wt%.

[0118] Example 3

[0119] (1) Preparation of high-activity lignin: Add 80.2 g of water and 2.4 g of catalyst NaOH to a three-necked flask equipped with a stirrer and a condenser; heat the system to the set temperature of 80 °C, and sequentially add 13.6 g of enzymatically hydrolyzed lignin and 3.8 g of phenol under stirring, continue stirring, heat and reflux for 1.5 h; after the reaction is completed, add hydrochloric acid to adjust the pH to 3.0 to precipitate the product, and obtain the product high-activity lignin by centrifugal separation, washing, and vacuum drying.

[0120] (2) Preparation of lignin alcohol ether: Dissolve 60.0 g of high-activity lignin in 38.0 g of water, add sodium hydroxide to adjust the pH value of the system to 12.5, and stir until completely dissolved; heat the system to 60 °C, add 2 g of epichlorohydrin, stop the reaction after reacting for 2 h, cool the system to room temperature, separate, wash, and dry to obtain the etherification product; take 6 g of the etherification product and add it to 3.9 g of water, heat the system to 40 °C, add 0.1 g of pentaerythritol, stop the reaction after reacting for 1 h, cool the system to room temperature, separate and purify to obtain lignin alcohol ether.

[0121] (3) Mix 2.2 g of lignin alcohol ether and 7.8 g of Span 80 evenly to obtain an emulsifier containing lignin alcohol ether.

[0122] The emulsifier containing lignin alcohol ether was used for the inverse emulsion synthesis of acrylamide polymers by the same method as in Example 1. The obtained emulsion product had a gel content of 0.8 wt%, a dissolution time of 2 min, was stratified after storage at room temperature for 135 days, the polymer viscosity-average molecular weight was 15.8 million, and the residual monomer content was 0.05 wt%.

[0123] Example 4

[0124] The same preparation method as in Example 1 was adopted, except that 2.5 g of lignin alcohol ether and 7.5 g of Span60 were mixed evenly to obtain the emulsifier containing lignin alcohol ether.

[0125] The emulsifier containing lignin alcohol ether was used for the inverse emulsion synthesis of acrylamide polymers by the same method as in Example 1. The obtained emulsion product had a gel content of 0.5 wt%, a dissolution time of 1 min, was stratified after storage at room temperature for 155 days, the polymer viscosity-average molecular weight was 19.8 million, and the residual monomer content was 0.05 wt%.

[0126] Example 5

[0127] The same preparation method as in Example 1 was adopted, except that 3 g of lignin alcohol ether and 7 g of Span 60 were mixed evenly to obtain the emulsifier containing lignin alcohol ether.

[0128] The emulsifier containing lignin alcohol ether was used for the inverse emulsion synthesis of acrylamide polymers by the same method as in Example 1. The obtained emulsion product had a gel content of 0.6 wt%, a dissolution time of 2 min, was stratified after storage at room temperature for 150 days, the polymer viscosity-average molecular weight was 20.1 million, and the residual monomer content was 0.09 wt%.

[0129] Example 6

[0130] The same preparation method as in Example 1 was adopted, except that 2 g of lignin alcohol ether and 8 g of Span 60 were mixed evenly to obtain the emulsifier containing lignin alcohol ether.

[0131] The emulsifier containing lignin alcohol ether was used for the inverse emulsion synthesis of acrylamide polymers by the same method as in Example 1. The obtained emulsion product had a gel content of 1 wt%, a dissolution time of 3 min, was stratified after storage at room temperature for 140 days, the polymer viscosity-average molecular weight was 15.1 million, and the residual monomer content was 0.12 wt%.

[0132] Comparative Example 1

[0133] The experiment was carried out according to the method of Example 1, except that the enzymatically hydrolyzed lignin was replaced by sodium lignosulfonate. The obtained emulsion product had a gel content of 3.1 wt%, a dissolution time of 5 min, delaminated after storage at room temperature for 15 days, a polymer viscosity-average molecular weight of 12.2 million, and a residual monomer content of 0.61 wt%.

[0134] Comparative Example 2

[0135] The experiment was carried out according to the method of Example 1, except that 3.8 g of phenol was replaced by the same mass of water. The obtained emulsion product had a gel content of 12.1 wt%, a dissolution time of 4 min, delaminated after storage at room temperature for 3 days, a polymer viscosity-average molecular weight of 11.3 million, and a residual monomer content of 0.81 wt%.

[0136] Comparative Example 3

[0137] The experiment was carried out according to the method of Example 1, except that 2.2 g of lignin alcohol ether was replaced by the same mass of Span 60. The obtained emulsion product had a gel content of 2.3 wt%, a dissolution time of 3 min, delaminated after storage at room temperature for 10 days, a polymer viscosity-average molecular weight of 13.6 million, and a residual monomer content of 0.23 wt%.

[0138] Comparative Example 4

[0139] The experiment was carried out according to the method of Example 1, except that 7.8 g of Span 60 was replaced by the same mass of lignin alcohol ether.

[0140] When the emulsifier containing lignin alcohol ether was used in the process of inverse emulsion synthesis of acrylamide polymers, the obtained emulsion product had a gel content of 42.1 wt%, a dissolution time of 12 min, delaminated immediately at room temperature, a polymer viscosity-average molecular weight of 4.1 million, and a residual monomer content of 2.6 wt%.

[0141] Comparative Example 5

[0142] The experiment was carried out according to the method of Example 1, except that the phenolated modified lignin was used to replace the same mass of lignin alcohol ether. The phenolated modified lignin in Example 1 and 7.8 g of Span 60 were directly mixed evenly to obtain a composite emulsifier.

[0143] The obtained emulsion product had a gel content of 50.9 wt%, could not be dissolved, delaminated immediately at room temperature, a polymer viscosity-average molecular weight of 3.3 million, and a residual monomer content of 6.98 wt%.

[0144] The present invention has been described in detail above in conjunction with specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present invention and their implementation manners, and all of these fall within the scope of the present invention. The protection scope of the present invention shall be subject to the appended claims.

[0145] All publications, patent applications, patents and other references mentioned in this specification are hereby incorporated by reference in their entirety. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0146] When this specification uses prefixes such as "known to those skilled in the art", "prior art" or their similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by such prefixes cover those commonly used in the art at the time when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as suitable for similar purposes.

[0147] In the context of this specification, any matter or thing not mentioned, except for what is expressly stated, shall directly apply those known in the art without any change.

Claims

1. A lignin alcohol ether, characterized in that: The lignin alcohol ether is obtained by sequentially reacting raw materials including phenolic modified lignin, epoxy haloalkane, and polyol; the phenolic modified lignin is selected from phenolic modified lignin modified by alkali catalysis.

2. A preparation method of lignin alcohol ether, characterized in that, It includes the following steps: Step (A): Add phenolic modified lignin to water, adjust the pH, and wait until the phenolic modified lignin is completely dissolved, then add epoxy haloalkane for heating reaction to obtain lignin ether; wherein, the phenolic modified lignin is selected from phenolic modified lignin modified by alkali catalysis; Step (B): Carry out a contact reaction between the lignin ether and polyol in water to obtain lignin alcohol ether; Preferably used for preparing the lignin alcohol ether described in claim 1.

3. According to the method for preparing the lignin alcohol ether described in claim 2, characterized in that: In step (A), The epoxy haloalkane is selected from epichlorohydrin; and / or, Adjust the pH value to 12.5 - 13.5; and / or, Based on the total mass of water, phenolic modified lignin, and epoxy haloalkane added in this step being 100%, The addition amount of phenolic modified lignin is 40 - 60 wt%; The addition amount of epichlorohydrin is 2 - 5 wt%; The temperature of the heating reaction is 60 - 70 °C; and / or, The time of the heating reaction is 2 - 8 h.

4. According to the method for preparing the lignin alcohol ether described in claim 2, characterized in that: In step (B), The polyol is selected from at least one of glycerol and pentaerythritol; and / or, Based on the total mass of water, lignin ether, and polyol added in this step being 100%, The addition amount of lignin ether is 40 - 60 wt%; The addition amount of polyol is 1 - 3 wt%; The temperature of the contact reaction is 30 - 45 °C; and / or, The time of the contact reaction is 1 - 4 h.

5. According to the method for preparing the lignin alcohol ether described in claim 2, characterized in that: The preparation method of phenolic modified lignin is: After carrying out a contact reaction on raw materials including lignin, phenolic modifier, and alkaline catalyst in water, optionally adjust the pH to obtain phenolic modified lignin; Preferably, The lignin is selected from at least one of alkali lignin and enzymatically hydrolyzed lignin; and / or, The phenolic modifier is selected from at least one of phenol and hydroquinone; and / or, The alkaline catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, and ammonia water; and / or, Based on the total mass of lignin, phenolic modifier, alkaline catalyst, and water added in this step being 100%, The addition amount of lignin is 10 - 15 wt%; The mass ratio of the phenolic modifier to the lignin is 0.2 - 0.4:1; The mass ratio of the alkaline catalyst to the lignin is 0.12 - 0.3:1; and / or, The temperature of the contact reaction is 70 - 85 °C; and / or, The contact reaction time is 0.5 - 2 h; Adjust the pH = 2 - 3.

6. An emulsifying system composition containing lignin alcohol ether, characterized in that: The emulsifying system composition includes span and lignin alcohol ether; The lignin alcohol ether is the lignin alcohol ether described in claim 1 or the lignin alcohol ether prepared by the preparation method described in any one of claims 2 - 5.

7. The emulsifying system composition containing lignin alcohol ether according to claim 6, characterized in that: In the emulsifying system composition, the content of Span is 70-90 wt%; the content of lignin alcohol ether is 10-30 wt%; Preferably, the content of Span is 75-80 wt%; the content of lignin alcohol ether is 20-25 wt%.

8. The emulsifying system composition containing lignin alcohol ether according to claim 6, characterized in that the Span is selected from at least one of Span 60, Span 80, and Span 83.

9. A method for preparing an emulsified system composition containing lignin alcohol ether according to any one of claims 6-8, characterized in that, Comprising the following steps: Mix Span and lignin alcohol ether evenly to obtain the emulsifying system composition.

10. An emulsion containing an acrylamide polymer, characterized in that, Using the raw materials including the emulsifying system composition containing lignin alcohol ether, monomer, initiator, and chelating agent according to any one of claims 6-8 for inverse emulsion synthesis to obtain an acrylamide polymer emulsion.

11. A preparation method of an emulsion containing an acrylamide polymer, characterized in that: Form an oil solution by mixing the emulsifying system composition with an organic solvent; Mix a vinyl monomer, optionally a sulfonic acid monomer, a chelating agent, a part of the initiator, and water to form an aqueous solution; Mix the oil solution and the aqueous solution to form a water-in-oil emulsion; After deoxygenating the water-in-oil emulsion, add the remaining initiator for polymerization reaction to obtain an emulsion containing an acrylamide polymer; The emulsifying system composition is selected from the emulsifying system composition according to any one of claims 6-8; Preferably used for the preparation of the emulsion containing an acrylamide polymer according to claim 10.

12. The preparation method of the emulsion containing an acrylamide polymer according to claim 10, characterized in that: The organic solvent is selected from at least one of white oil and kerosene; and / or, The mass ratio of the organic solvent to the emulsifying system composition is 1:0.05-0.2; and / or, The vinyl monomer is selected from at least one of acrylamide, acrylic acid, and N-isopropylacrylamide; and / or, When containing a sulfonic acid monomer, the sulfonic acid monomer is selected from at least one of 2-acrylamido-2-methylpropanesulfonic acid and 2-acryloyloxy-2-methylpropanesulfonic acid; and / or, The chelating agent is selected from at least one of disodium ethylenediaminetetraacetate and trisodium ethylenediaminetetraacetate; and / or, The initiator is selected from at least one of redox initiators and azo initiators; and / or, In the aqueous solution, the content of the vinyl monomer is 40-50 wt%; the content of the sulfonic acid monomer is 0-50 wt%; the content of the chelating agent is 0.01-0.1 wt%; the content of the part of the initiator added is 0.01-0.1 wt%; and / or, The mass ratio of the part of the initiator to the remaining initiator is 1-4:1; and / or, The mass ratio of the aqueous solution to the oil solution is 1-3:1; and / or, The temperature of the polymerization reaction does not exceed 40°C; preferably, the temperature of the polymerization reaction does not exceed 35°C; and / or, The time of the polymerization reaction is 2-6 h.

13. Application of the emulsion containing an acrylamide polymer according to claim 10 or the emulsion containing an acrylamide polymer prepared by the method according to any one of claims 11-12 in oil exploitation.