A self-stabilizing oil-in-oil emulsion using graft-modified heterocyclic aramid fibers and its preparation method

Abstract

This invention relates to the field of colloidal interface technology, and more particularly to a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers and its preparation method. The method involves directly grafting and modifying heterocyclic aramid fibers after low-temperature polymerization to obtain grafted modified heterocyclic aramid fibers that are amphiphilic polymers. By utilizing the affinity of the nonpolar ends of the amphiphilic polymer backbone for the external phase of the emulsion and the affinity of the polar ends of the side chains for the internal phase, the oil-in-oil emulsion is stabilized, resulting in a self-stabilizing emulsion that does not rely on surfactants. This method is simple, low-cost, and more economical. It solves the problem of high surfactant dependence and poor emulsion stabilization in existing oil-in-oil emulsion technologies.

Description

Technical Field

[0001] This invention relates to the field of colloidal interface technology, specifically to a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers and its preparation method. Background Technology

[0002] Emulsions are an important component of commercial products, widely used in cosmetics, pharmaceuticals, food, and other chemical products. Composed of two or more immiscible phases, typically stabilized by molecular surfactants, polymers, proteins, and / or solid particles, emulsions are an integral part of our daily lives. Emulsions can be classified into conventional emulsions such as water-in-oil emulsions (W / O) and oil-in-water emulsions (O / W), and unconventional emulsions such as various emulsions (W / O / W, O / W / O, W / W / W, or O / O / O), water-in-water emulsions (W / W), and oil-in-oil emulsions (O / O). O / O emulsions are formed by two oil phases with lower dielectric constants, or by one oil phase replaced by an anhydrous phase (with a higher dielectric constant) (polar non-aqueous phase). The stability of oil-in-oil emulsions largely depends on the surfactant. The preparation of emulsions generally requires a large amount of surfactants and co-surfactants, especially when there are many oily substances as the oil phase in oil-in-oil emulsions. The use of large amounts of surfactants and co-surfactants not only increases the cost of emulsion preparation and reduces its economic efficiency, but also causes adverse effects on water, soil and air during the production, use and disposal of surfactants and co-surfactants. Therefore, finding ways to reduce the amount of excipients is a pressing development requirement. Summary of the Invention

[0003] To address the problem that the stability of oil-in-oil emulsions in existing technologies is highly dependent on surfactants and has poor emulsion stabilization, this invention provides a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers and its preparation method.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] This invention provides a method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers, comprising:

[0006] A solution system was prepared using N,N-dimethylacetamide and lithium chloride;

[0007] 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-phenylenediamine and terephthaloyl chloride were added to the solution system, and the reaction yielded a heterocyclic aramid solution.

[0008] Under water bath conditions, an alkaline substance and a long-chain brominated alkane were added to a heterocyclic aramid solution to obtain a grafted modified heterocyclic aramid solution.

[0009] Self-stabilizing oil-in-oil emulsions were prepared using graft-modified heterocyclic aramid solutions.

[0010] Optionally, the solid content of lithium chloride in the solution system is 3wt% to 3.5wt%, and the mass ratio of N,N-dimethylacetamide to lithium chloride is (350 to 700): (12 to 24).

[0011] Optionally, the molar ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-phenylenediamine and terephthaloyl chloride is (9-4):(1-6):10.

[0012] Optionally, the sum of the molar amounts of 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-phenylenediamine is equal to the molar amount of terephthaloyl chloride.

[0013] Optionally, the temperature of the water bath is 80℃~90℃.

[0014] Optionally, the amount of alkaline substance used is 1% to 3% of the total mass of the heterocyclic aramid solution system.

[0015] Optionally, the brominated long-chain alkanes include one or more of hexadecane, octadecane, eicosane, docosane, and tetradecane.

[0016] Optionally, the molar ratio of the brominated long-chain alkane to 2-(4-aminophenyl)-5-aminobenzimidazole is 1:1.

[0017] Optionally, the mass ratio of the N,N-dimethylacetamide and lithium chloride to the heterocyclic aramid is (350-700):(12-24):7.

[0018] The present invention also provides a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers, prepared by the above method.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses a self-stabilized oil-in-oil emulsion using graft-modified heterocyclic aramid fibers and its preparation method. The method involves directly grafting heterocyclic aramid fibers after low-temperature polymerization to obtain graft-modified heterocyclic aramid fibers that are amphiphilic polymers. Utilizing the affinity of the nonpolar ends of the main chain of this amphiphilic polymer for the external phase of the emulsion and the affinity of the polar ends of the side chains for the internal phase, the oil-in-oil emulsion is stabilized, resulting in a self-stabilizing emulsion that does not rely on surfactants. Furthermore, for oil-in-oil emulsions with phase change function, this amphiphilic polymer can also serve as an encapsulation shell for phase change materials and a solid-solid phase change material. As an encapsulation shell, heterocyclic aramid fibers possess high mechanical properties and rapid encapsulation capabilities, enabling stable encapsulation of the phase change material. As a solid-solid phase change material, it can store and release heat, enhancing subsequent phase change performance and providing performance support for subsequent processing. The preparation method is simple, requires suitable reaction temperatures, and offers certain economic benefits.

[0021] The present invention also provides an oil-in-oil emulsion prepared by the above method, which has self-stability, does not require the use of surfactants or main surfactants to achieve stability, and has good stabilization effect and low preparation cost. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers according to the present invention.

[0023] Figure 2 This is a process flow diagram of a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers, as shown in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the grafting process of the amphiphilic polymer in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the stable state of the oil-in-oil emulsion prepared in an embodiment of the present invention.

[0026] Figure 5 The images show a comparison of the stable state of the oil-in-oil emulsion prepared in the embodiments of the present invention and the stable state of the oil-in-oil emulsion prepared using surfactant F127. The left image shows the oil-in-oil state stabilized using surfactant F127, and the right image shows the self-stabilized oil-in-oil state prepared using the embodiments of the present application. Detailed Implementation

[0027] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0029] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0030] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0031] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0032] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0033] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0034] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0035] This invention discloses a method for preparing a self-stabilizing oil-in-oil emulsion using grafted modified heterocyclic aramid fibers, referring to... Figure 1 ,include:

[0036] S1: A solution system was prepared using N,N-dimethylacetamide (DMAC) and lithium chloride, as follows:

[0037] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system. The solid content of lithium chloride was 3wt% to 3.5wt%, and the mass ratio of N,N-dimethylacetamide to lithium chloride was (350 to 700): (12 to 24).

[0038] S2: 2-(4-aminophenyl)-5-aminobenzimidazole (APBZ), 1,4-phenylenediamine (PPD), and terephthaloyl chloride (TPC) are added to the solution system, and the reaction yields a heterocyclic aramid solution, specifically:

[0039] To the dissolution system, 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-phenylenediamine were added, and the mixture was stirred and dissolved in a water bath at 0℃~5℃. Then, terephthaloyl chloride was added, the ice-water bath was removed, and the reaction was allowed to proceed for at least 1 hour to obtain a heterocyclic aramid solution. The sum of the molar amounts of 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-phenylenediamine was equal to that of terephthaloyl chloride. The molar ratio of phenylenediamine to terephthaloyl chloride is (9-4):(1-6):10; the solid content of heterocyclic aramid (HA) in the heterocyclic aramid solution is 1wt%-2wt%, and the mass ratio of N,N-dimethylacetamide, lithium chloride and heterocyclic aramid is (350-700):(12-24):7; the sum of the molar amounts of 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-phenylenediamine is equal to the molar amount of terephthaloyl chloride.

[0040] S3: Under water bath conditions, an alkaline substance and a brominated long-chain alkane are added to a heterocyclic aramid solution to obtain a grafted modified heterocyclic aramid solution, specifically:

[0041] Add 1%–3% (by mass) of an alkaline substance to the heterocyclic aramid solution to provide an alkaline environment. Heat and stir until the alkaline substance dissolves. Then add a brominated long-chain alkane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole in S1. Stir for 2 hours in a water bath at 80°C–90°C to obtain a grafted modified heterocyclic aramid solution. The alkaline substance includes one of sodium hydroxide, potassium carbonate, and potassium tert-butoxide. The brominated long-chain alkane includes one or more of hexadecane, octadecane, eicosane, docosane, and tetracosane.

[0042] S4: A self-stabilized oil-in-oil emulsion is prepared using a graft-modified heterocyclic aramid solution; preferably, a phase change material is directly added to the graft-modified heterocyclic aramid solution, followed by heating and homogenization emulsification to obtain the self-stabilized oil-in-oil emulsion, specifically as follows:

[0043] Long-chain alkanes, i.e., phase change materials, are added to a grafted and modified heterocyclic aramid solution. The mixture is homogenized and emulsified at 30°C to 60°C, ensuring that the heating temperature is higher than the phase change temperature of the phase change material, to obtain a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid. The phase change material is one or more of phase change paraffin, octadecane, hexadecane, and docosane. The mass ratio of the added phase change material to the heterocyclic aramid is 1:(1 to 9).

[0044] This method involves directly grafting heterocyclic aramid fibers after low-temperature polymerization to obtain grafted heterocyclic aramids that are amphiphilic polymers. Utilizing the affinity of the nonpolar ends of the polymer backbone for the external phase of the emulsion and the polar ends of the side chains for the internal phase, the oil-in-oil emulsion is stabilized, resulting in a self-stabilizing emulsion that does not rely on surfactants. Furthermore, for oil-in-oil emulsions with phase change capabilities, this amphiphilic polymer can also serve as an encapsulation shell for phase change materials (PCMs) and as a solid-solid PCM material. As an encapsulation shell, heterocyclic aramids possess high mechanical properties and a rapid encapsulation method, enabling stable encapsulation of PCMs. As a solid-solid PCM material, it can store and release heat, enhancing subsequent PCM performance and providing performance support for subsequent processing. The preparation method is simple, requires minimal reaction temperature, and offers certain economic benefits.

[0045] Example 1

[0046] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0047] Example 2

[0048] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 8:2:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0049] Example 3

[0050] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 7:3:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0051] Example 4

[0052] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 6:4:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0053] Example 5

[0054] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 5:5:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0055] Example 6

[0056] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 4:6:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 700:24:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.0 wt%. Sodium hydroxide (1% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, hexadecane bromodiphenyl ether (1:1 molar ratio with 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, phase change paraffin was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0057] Example 7

[0058] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0059] Example 8

[0060] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 8:2:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0061] Example 9

[0062] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 7:3:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0063] Example 10

[0064] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 6:4:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0065] Example 11

[0066] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 5:5:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0067] Example 12

[0068] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 4:6:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 580:20:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.2 wt%. Potassium carbonate (2% of the total mass of the system) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium carbonate dissolved. Then, bromooctadecane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; hexadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:2, and the mixture was heated at 30℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0069] Example 13

[0070] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0071] Example 14

[0072] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 8:2:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0073] Example 15

[0074] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 7:3:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0075] Example 16

[0076] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 6:4:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0077] Example 17

[0078] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 5:5:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0079] Example 18

[0080] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 4:6:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 466:16.3:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.5 wt%. 3% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromoeicosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; octadecane was added according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:4, and the mixture was heated at 45℃ and homogenized to emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0081] Example 19

[0082] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by mass of the total system weight) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0083] Example 20

[0084] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and after mechanical stirring under 0°C ice-water bath conditions, TPC was added. The ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 8:2:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by total mass) of the system was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0085] Example 21

[0086] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 7:3:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by total mass) of the system was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0087] Example 22

[0088] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 6:4:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by total mass) of the system was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0089] Example 23

[0090] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and after mechanical stirring under 0°C ice-water bath conditions, TPC was added. The ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 5:5:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by mass of the total system weight) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0091] Example 24

[0092] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 4:6:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 400:14:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 1.75 wt%. 3% sodium hydroxide (by mass of the total system weight) was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the sodium hydroxide dissolved. Then, bromododecane (1:1 molar ratio to 2-(4-aminophenyl)-5-aminobenzimidazole) was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:7, eicosane was added, and the mixture was heated at 50℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0093] Example 25

[0094] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:1, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0095] Example 26

[0096] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 8:2:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:9, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0097] Example 27

[0098] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and after mechanical stirring under 0°C ice-water bath conditions, TPC was added. The ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 7:3:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated at 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:9, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0099] Example 28

[0100] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and after mechanical stirring under 0°C ice-water bath conditions, TPC was added. The ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 6:4:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:9, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0101] Example 29

[0102] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and after mechanical stirring under 0°C ice-water bath conditions, TPC was added. The ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 5:5:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:9, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0103] Example 30

[0104] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 4:6:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% (by mass) of potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to phase change paraffin in the heterocyclic aramid solution of 1:9, docosane was added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a self-stabilized oil-in-oil emulsion of modified heterocyclic aramid.

[0105] Example 31

[0106] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to docosane, n-octadecane and phase change paraffin in the heterocyclic aramid solution of 1:3:3:3, mixed phase change materials were added, and the mixture was heated at 60℃ to homogenize and emulsify, thus obtaining a modified heterocyclic aramid self-stabilized oil-in-oil emulsion.

[0107] Example 32

[0108] Lithium chloride was dissolved in N,N-dimethylacetamide to obtain a solution system with a lithium chloride solid content of 3.3 wt%. APBZ and PPD were added to the solution system, and then mechanically stirred until dissolved under an ice-water bath at 0°C. TPC was then added, the ice-water bath was removed, and the reaction was allowed to proceed for 1 hour to obtain a heterocyclic aramid solution. The molar ratio of APBZ, PPD, and TPC was 9:1:10, and the mass ratio of DMAC, LiCl, and heterocyclic aramid was 350:12:7. The heterocyclic aramid solution had a heterocyclic aramid solid content of 2.0 wt%. 1% potassium tert-butoxide was added to the heterocyclic aramid solution to provide an alkaline environment. The mixture was heated and stirred until the potassium tert-butoxide dissolved. Then, bromotetracosane with a molar ratio of 1:1 to 2-(4-aminophenyl)-5-aminobenzimidazole was added, and the mixture was heated to 80°C. Under the condition of ℃ water bath, after stirring for 2 h, a grafted modified heterocyclic aramid solution was obtained; according to the mass ratio of heterocyclic aramid to hexadecane, n-octadecane, docosane and phase change paraffin in the heterocyclic aramid solution of 1:1:1:1:1, mixed phase change materials were added, and the mixture was heated at 60℃ to homogenize and emulsify, thereby obtaining a modified heterocyclic aramid self-stabilized oil-in-oil emulsion.

[0109] Taking Examples 7-12 as examples, see Figure 3 After low-temperature polymerization of heterocyclic aramid fibers, octadecane bromide is used to bind to the active sites on the imidazole of the heterocyclic aramid fibers to perform graft modification, resulting in graft-modified heterocyclic aramid fibers, i.e., amphiphilic polymers. These amphiphilic polymers are then used as emulsion stabilizers. (See [link to documentation]). Figure 4By utilizing the affinity of the nonpolar ends of the amphiphilic polymer backbone for the external phase of the emulsion and the polar ends of the side chains for the internal phase of the emulsion, the stabilization of oil-in-oil emulsions is achieved, reaching a self-stabilized state independent of surfactants. See also Figure 5 By comparing the micrographs of heterocyclic aramid oil-in-oil emulsions stabilized using the conventional surfactant F127 and those stabilized using the amphiphilic polymer described in this invention, it is shown that the amphiphilic polymer has better stabilizing ability than the conventional method.

[0110] In summary, this invention provides a self-stabilized oil-in-oil emulsion using graft-modified heterocyclic aramid fibers and its preparation method. This method involves directly grafting heterocyclic aramid fibers after low-temperature polymerization to obtain graft-modified heterocyclic aramid fibers that are amphiphilic polymers. By utilizing the affinity of the nonpolar ends of the amphiphilic polymer backbone for the external phase of the emulsion and the affinity of the polar ends of the side chains for the internal phase, the oil-in-oil emulsion is stabilized. This results in a self-stabilizing emulsion that does not rely on surfactants, achieving a simple and low-cost method with better economic efficiency.

[0111] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers, characterized in that, include: A solution system was prepared using N,N-dimethylacetamide and lithium chloride; 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-phenylenediamine, and terephthaloyl chloride were added to a solution to obtain a heterocyclic aramid solution; the molar ratio of 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-phenylenediamine, and terephthaloyl chloride was (9-4):(1-6):10; the sum of the molar amounts of 2-(4-aminophenyl)-5-aminobenzimidazole and 1,4-phenylenediamine was equal to the molar amount of terephthaloyl chloride. Under water bath conditions, an alkaline substance and a brominated long-chain alkane were added to a heterocyclic aramid solution to obtain a grafted modified heterocyclic aramid solution; the molar ratio of the brominated long-chain alkane to 2-(4-aminophenyl)-5-aminobenzimidazole was 1:1; the mass ratio of N,N-dimethylacetamide and lithium chloride to the heterocyclic aramid was (350-700):(12-24):

7. Self-stabilizing oil-in-oil emulsions were prepared using graft-modified heterocyclic aramid solutions.

2. The method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers according to claim 1, characterized in that, The solid content of lithium chloride in the solution system is 3wt% to 3.5wt%.

3. The method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers according to claim 1, characterized in that, The temperature of the water bath is 80℃~90℃.

4. The method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers according to claim 1, characterized in that, The amount of alkaline substance used is 1% to 3% of the total mass of the heterocyclic aramid solution system.

5. The method for preparing a self-stabilized oil-in-oil emulsion using grafted modified heterocyclic aramid fibers according to claim 1, characterized in that, The brominated long-chain alkanes include one or more of the following: hexadecane, octadecane, eicosane, docosane, and tetracosane.

6. A self-stabilized oil-in-oil emulsion utilizing grafted modified heterocyclic aramid fibers, characterized in that, Prepared using the method described in any one of claims 1-5.

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