A porous epoxy-based high internal phase emulsion based on pickering high internal phase emulsion method and a preparation method thereof

Abstract

The application provides a porous epoxy-based high internal phase emulsion based on a Pickering high internal phase emulsion method and a preparation method thereof, the porous epoxy-based high internal phase emulsion comprises a continuous phase and a dispersed phase, the continuous phase comprises bisphenol A type epoxy resin, a curing agent, a diluent and a dispersant, the dispersed phase comprises an alkaline silica sol aqueous solution, and the dispersant is a mixture of OP-10 and NP-4. The polymer formed by the high internal phase emulsion has a stable multi-level pore structure in the interior, and the structure has micrometer-level large pores and stable sub-micrometer-level small pores in the micrometer-level large pores, thereby forming a multi-level pore structure, and the multi-level pore structure has great application value in adsorption materials and catalytic materials.

Description

A porous epoxy-based high internal phase emulsion based on Pickering high internal phase emulsion method and its preparation method Technical Field

[0001] This invention belongs to the field of polymers, and in particular relates to a porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method and its preparation method. Background Technology

[0002] High internal phase emulsion polymers (PolyHIPEs) are a class of widely used porous polymer materials suitable for applications such as adsorbents, electrochemical sensors, filters, and controlled drug release. PolyHIPEs are synthesized in high-viscosity, high internal phase emulsions, which consist of a high-concentration internal dispersed phase and a continuous phase. The internal phase typically acts as a pore-forming agent, accounting for 74% or more of the total volume; monomers exist in the continuous phase, forming porous polymers through polymerization. The preparation of high internal phase emulsions usually requires only simple mechanical stirring equipment, without the need for additional expensive equipment. High internal phase emulsions are typically composed of oil-water or water-oil systems. When water is used as the dispersed phase, a porous structure can spontaneously form after continuous phase polymerization and subsequent water evaporation, without the need for additional template extraction steps, making it an excellent method for preparing porous materials.

[0003] In traditional high internal phase emulsion preparation techniques, the monomers to be polymerized exist in the continuous phase as monomers, and polymerization is initiated under the conditions of an initiator and heating to ultimately form a porous polymer. This method is complex and cumbersome. On the other hand, common high internal phase emulsion polymers usually use rigid monomers, such as styrene, while epoxy resin, being an elastic material, is not suitable for preparing porous polymers. Although there are reports in the prior art of using epoxy resin as the polymer material, such as CN104755535B-waterborne epoxy resin blend dispersion, this patent proposes a method for preparing high internal phase emulsions by solvent-free melt shearing, involving a mixture of high molecular weight epoxy resin (epoxy equivalent 800-10000 g / eq) and liquid epoxy resin (epoxy equivalent 100-200 g / eq). The dispersant is selected from ethoxylated phenol sulfate, ethylene oxide-propylene oxide block copolymer (such as Pluronic F108), etc., and emulsification is carried out at 50-150℃ to form a high internal phase emulsion. However, this method involves pre-blending with two types of high-molecular-weight epoxy resins, making the process relatively complex. Constructing porous structures using only pure liquid epoxy resin is also an existing technology. Third, in existing technologies, the pore structures formed by high internal phase emulsions are typically micron-sized, failing to form stable hierarchical pores with both micron and submicron structures. Hierarchical porous materials are particularly important in applications such as catalysis and adsorption. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and proposes a porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method and its preparation method.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] In a first aspect, the present invention provides a porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method, comprising a continuous phase and a dispersed phase, wherein the continuous phase comprises bisphenol A type epoxy resin, a curing agent, a diluent and a dispersant, the dispersed phase comprises an alkaline silica sol aqueous solution, and the dispersant is a mixture of OP-10 (dodecylphenol polyoxyethylene ether) and NP-4 (nonylphenol polyoxyethylene ether-4).

[0007] Preferably, the mass ratio of the bisphenol A type epoxy resin, curing agent, diluent and dispersant is (1-5):(5-10):(1-5):(5-10), and the mass ratio of OP-10 to NP-4 in the dispersant is 1:1.

[0008] Preferably, the amount of the dispersed phase added is 74%-90% of the total mass of the continuous phase and the dispersed phase.

[0009] Preferably, the bisphenol A type epoxy resin is selected from one or a mixture of two or more of E51, E42, E20, and E44, and more preferably E44.

[0010] Preferably, the curing agent is a room temperature curing agent, selected from one or more of T-31, 650, 651, and 593, more preferably 593.

[0011] Preferably, the diluent is selected from one or a mixture of two or more of MAK (methyl n-pentyl ketone), MIBK (methyl isobutyl ketone), and cyclohexanone, more preferably MIBK.

[0012] Preferably, the mass concentration of the alkaline silica sol aqueous solution is 20%-60%.

[0013] Secondly, the present invention provides a method for preparing porous epoxy-based internal phase emulsions based on the Pickering internal phase emulsion method, comprising the following steps:

[0014] Bisphenol A type epoxy resin, curing agent, diluent, and dispersant are mixed and stirred thoroughly for 0.5-2 hours within a temperature range of 20℃-80℃ to obtain a mixed solution. Then, an alkaline silica sol aqueous solution is added dropwise to the mixed solution while maintaining room temperature during the dropwise addition process. The stirring speed is 200-1000 rpm until no dispersed phase solution appears in the mixed solution, at which point stirring is stopped to obtain a porous epoxy-based high internal phase emulsion.

[0015] This invention uses an alkaline silica sol aqueous solution as the dispersed phase and bisphenol A type epoxy resin, curing agent, diluent, and NP-4 and OP-10 dispersants as the continuous phase to prepare a high internal phase emulsion. The choice of dispersant is crucial for preparing a stable high internal phase emulsion. NP-4 and OP-10 are both nonionic surfactants. The stability of the emulsion is mainly determined by atomic repulsion. NP-4 is lipophilic, and OP-10 is hydrophilic. The two dispersants are used in combination with an alkaline silica sol aqueous solution as the dispersed phase. Due to the presence of silica nanoparticles, the hydrophilicity of these particles allows them to aggregate at the interface of the three phases, forming a layer of colloidal particles. This also generates strong spatial repulsion between droplets, enhancing the mechanical properties of the interfacial film. The nonionic emulsifiers protect the silica particles, resulting in a synergistic effect that further improves the stability of the silica particles. The greater the surface coverage of silica nanoparticles, the stronger the electrostatic or steric stabilizing effect, and the higher the electrolyte stability of the high internal phase emulsion. We added an alkaline silica sol aqueous solution as the dispersed phase to the continuous phase. The dispersed phase droplets existed in irregular polyhedral shapes and were tightly packed together. Under the action of NP-4 and OP-10, the continuous phase separated the polyhedral droplets in the form of a thin liquid film. As the reaction proceeded, the continuous phase continuously underwent cross-linking polymerization, thereby forming a three-dimensional cross-linked network structure that encapsulated the dispersed phase droplets. The dispersed phase water droplets in the network structure evaporated, thus forming a porous structure.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) This invention utilizes liquid epoxy resin to construct a high internal phase emulsion polymer. Taking liquid epoxy resin as an example, this method is simpler because it only uses this one type of resin to form a continuous phase polymer.

[0018] (2) The polymerization process of the high internal phase emulsion formed by the present invention does not require heating and can spontaneously react at room temperature without the need for additional heating and curing process, which is simple and easy to implement.

[0019] (3) The polymer formed by the high internal phase emulsion of the present invention has a stable hierarchical pore structure inside. The structure contains both micron-sized macropores and stable submicron-sized micropores inside the micron-sized macropores, thus forming a hierarchical pore structure. This hierarchical pore structure has great application value in adsorption materials and catalytic materials. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the preparation process of the porous epoxy-based high internal phase emulsion of the present invention;

[0021] Figure 2 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 1 after standing.

[0022] Figure 3 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 2 after standing.

[0023] Figure 4 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 3 after standing.

[0024] Figure 5 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 4 after standing.

[0025] Figure 6 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 5 after standing.

[0026] Figure 7 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 6 after standing.

[0027] Figure 8 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 7 after standing.

[0028] Figure 9 is a SEM image of the porous epoxy-based internal phase emulsion prepared in Example 8 after standing.

[0029] Figure 10 shows photographs of the porous epoxy-based internal phase emulsions prepared in Examples 1-8 after standing.

[0030] Figure 11 shows photographs of the porous epoxy-based internal phase emulsions prepared in Comparative Examples 1-6 after standing. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] In this document, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] In this document, when values ​​are described as ranges, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as the specific numerical values ​​falling within that range, regardless of whether the specific numerical value or specific subrange is explicitly specified.

[0034] In this article, the terms "multiple" or "more than" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0035] In this document, the terms "preferred" and "more preferred" are used only to describe implementation methods or embodiments with better effects, and should be understood as not constituting a limitation on the scope of protection of this invention.

[0036] In this document, terms such as "further" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0037] In this document, the term "about" means a specified value of + / - 10%, preferably + / - 5%, and more preferably + / - 1%.

[0038] In this article, the terms “include,” “including,” “have,” “contain,” etc., are all open-ended terms, meaning that they include but are not limited to.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention.

[0040] The present invention will be described in detail below with reference to embodiments.

[0041] Example 1

[0042] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.36 g), and OP-10 (0.36 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 7.92 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The process flow is shown in Figure 1. The prepared emulsion was placed in a small glass bottle, which was then inverted to observe whether it flowed downwards and whether it was a homogeneous phase. If no phase separation and downward flow of the emulsion occurred, it indicated that a stable high internal phase emulsion had been formed, as shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and then the structure was observed using a scanning electron microscope (Figure 2).

[0043] Example 2

[0044] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.46 g), and OP-10 (0.46 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 8.91 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 3).

[0045] Example 3

[0046] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 9.32 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 4).

[0047] Example 4

[0048] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.62 g), and OP-10 (0.62 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 10.52 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 5).

[0049] Example 5

[0050] E42 epoxy resin (0.5 g), 650 curing agent (0.53 g), methyl n-pentyl ketone (MAK, 0.5 g), NP-4 (0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 20.7 g of alkaline silica sol solution (20 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 6).

[0051] Example 6

[0052] E51 epoxy resin (0.4 g), T-31 curing agent (0.8 g), cyclohexanone (0.5 g), NP-4 (0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 24.3 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 7).

[0053] Example 7

[0054] E20 epoxy resin (1 g), T-31 curing agent (5 g), methyl isobutyl ketone (MIBK, 1 g), NP-4 (2.5 g), and OP-10 (2.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 34.2 g of alkaline silica sol solution (60 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 8).

[0055] Example 8

[0056] E20 epoxy resin (2.5 g), T-31 curing agent (5 g), methyl isobutyl ketone (MIBK, 2.5 g), NP-4 (2.5 g), and OP-10 (2.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form the continuous phase. Then, under continuous mechanical stirring at 200 rpm at room temperature, 60 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution until no obvious phase separation was observed. The emulsion was placed in a small glass bottle, which was then inverted to observe the formation of a stable high internal phase emulsion. The specific results are shown in Table 1. After the emulsion was allowed to stand in air for 24 hours, it was photographed (Figure 10), and the structure was then observed using a scanning electron microscope (Figure 9).

[0057] Comparative Example 1

[0058] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), and NP-4 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 9.32 g of alkaline silica sol solution (concentration 40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0059] Comparative Example 2

[0060] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 9.32 g of alkaline silica sol solution (concentration 40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0061] Comparative Example 3

[0062] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), and methyl isobutyl ketone (MIBK, 0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 9.32 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0063] Comparative Example 4

[0064] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 51.30 g of alkaline silica sol solution (concentration 40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0065] Comparative Example 5

[0066] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.5 g), and OP-10 (0.5 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 3.97 g of alkaline silica sol solution (concentration 40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0067] Comparative Example 6

[0068] E44 epoxy resin (0.4 g), 593 curing agent (0.8 g), methyl isobutyl ketone (MIBK, 0.5 g), NP-4 (0.2 g), and OP-10 (0.8 g) were placed in a 100 mL plastic beaker and stirred thoroughly at 40 °C for 1 h to form a continuous phase. Subsequently, under continuous mechanical stirring at 200 rpm at room temperature, 9.32 g of alkaline silica sol solution (40 wt%) was added dropwise to the above solution while stirring continuously. However, a homogeneous emulsion could not be formed. The specific results are shown in Table 1, and the photograph is shown in Figure 11.

[0069] Table 1. Formulation ratios and stability results of the examples and comparative examples.

[0070]

[0071] It should be noted that the continuous phase in the table also includes epoxy resin, curing agent, and diluent, which are not listed.

[0072] Stability rating for high internal phase emulsions: × Unstable; △ Partially stable; ○ Stable.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method, characterized in that: The mixture comprises a continuous phase and a dispersed phase. The continuous phase includes bisphenol A type epoxy resin, a curing agent, a diluent, and a dispersant. The dispersed phase includes an alkaline silica sol aqueous solution. The dispersant is a mixture of OP-10 and NP-4, with a mass ratio of OP-10 to NP-4 of 1:

1. The amount of the dispersed phase added is 74%-90% of the total mass of the continuous and dispersed phases. The diluent is selected from one or more of methyl pentyl ketone, methyl isobutyl ketone, and cyclohexanone, and the mass concentration of the alkaline silica sol aqueous solution is 20%-60%.

2. The porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to claim 1, characterized in that: The mass ratio of the bisphenol A type epoxy resin, curing agent, diluent and dispersant is (1-5):(5-10):(1-5):(5-10).

3. The porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to claim 1, characterized in that: The bisphenol A type epoxy resin is selected from one or a mixture of two or more of E51, E42, E20, and E44.

4. The porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to claim 1, characterized in that: The bisphenol A type epoxy resin is E44.

5. The porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to claim 1, characterized in that: The curing agent is a room temperature curing agent, selected from one or more of T-31, 650, 651, and 593.

6. The porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to claim 1, characterized in that: The diluent is methyl isobutyl ketone.

7. A method for preparing a porous epoxy-based high internal phase emulsion based on the Pickering high internal phase emulsion method according to any one of claims 1-6, characterized in that: The process includes the following steps: mixing bisphenol A type epoxy resin, curing agent, diluent, and dispersant, and stirring thoroughly for 0.5-2 hours within a temperature range of 20℃-80℃ to obtain a mixed solution. Then, an alkaline silica sol aqueous solution is added dropwise to the mixed solution while maintaining room temperature during the dropwise addition process. The stirring speed is 200-1000 rpm until no dispersed phase solution appears in the mixed solution, at which point stirring is stopped to obtain a porous epoxy-based high internal phase emulsion.

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