High internal phase emulsion foam as well as preparation method and application thereof

Abstract

The invention relates to high-internal-phase emulsion foam as well as a preparation method and application thereof. The high-internal-phase emulsion foam is prepared from the following raw materials in percentage by mass: 0.1-10% of an oil-phase component and 90-99.9% of a water-phase component, the oil phase component comprises modified natural oil, an emulsifier and a cross-linking agent; the aqueous phase component includes an electrolyte, an aqueous solvent, and an initiator. According to the high-internal-phase emulsion foam provided by the invention, through collaborative design of food-grade raw materials, the prepared high-internal-phase emulsion foam has high stability and high foam functionality, and the high-internal-phase emulsion foam has 100% biocompatibility in a medical scene and has no toxic residues.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foam materials, in particular to a high internal phase emulsion foam and a preparation method and application thereof. BACKGROUND

[0002] Medical materials have very high safety requirements, especially materials that directly contact wounds, mucous membranes or are implanted for a short period of time, which need to meet the standards of "non-toxicity, non-irritation, degradability and biocompatibility". The porous foam material prepared by high internal phase emulsion (HIPE) has the characteristics of high porosity, high connectivity of pore structure and large specific surface area, and has a wide application prospect in the medical field. The high internal phase emulsion porous foam material can also be applied to daily hygiene products, such as sanitary napkins, dressings, etc., and has the advantages of absorption, flow guidance, water locking, anti-back seepage or slow release.

[0003] In the preparation process of traditional HIPE foam materials, in order to achieve stable emulsification, chemical synthetic raw materials such as acrylate, styrene, divinylbenzene monomers and persulfate initiators are often used. These substances may have the risk of unreacted monomer residues, and contacting wounds can easily cause redness and allergy, which cannot be used for mucous membrane or short-term implantation scenarios, limiting their application in the medical field.

[0004] CN102838773A discloses a method for preparing an ultra-low density polymer porous material by freeze-drying using a water-in-oil high internal phase emulsion stabilized by styrene, acrylic acid and methyl methacrylate triblock copolymer nanoparticles as a precursor. Although this preparation method avoids the use of a large amount of surfactant, the raw materials used are not natural food-grade raw materials.

[0005] Some technologies attempt to use food-grade raw materials to prepare high internal phase emulsions, but lack the synergistic design of food-grade components, resulting in poor emulsion stability, low foam porosity and insufficient liquid absorption, which cannot meet the "high liquid absorption" requirement of medical dressings, and cannot support drug slow release and implantation functions.

[0006] CN106578335A discloses a method for preparing a stable high internal phase gelatinous wheat protein Pickering emulsion. This invention can obtain a wheat protein Pickering emulsion with high stability, good viscoelasticity and the ability to embed a large amount of oil, and has good prospects in the application of novel nutrient delivery carriers and food structure modification bases. However, this method requires the use of organic solvent ethanol, and the preparation process is complex. Moreover, the prepared is a water-in-oil high internal phase emulsion, and the internal phase is an oil phase.

[0007] Therefore, it has become a technical problem to be solved to develop a high internal phase emulsion foam with all edible components and stable emulsion. SUMMARY

[0008] To address the aforementioned technical problems, this invention provides a high internal phase emulsion foam, its preparation method, and its application. Through the synergistic design of food-grade raw materials, the prepared high internal phase emulsion foam exhibits high stability and high foam functionality. Furthermore, this high internal phase emulsion foam demonstrates 100% biocompatibility in medical applications and leaves no toxic residues.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a high internal phase emulsion foam, wherein the raw materials for preparing the high internal phase emulsion foam comprise, by mass percentage, 0.1-10% oil phase component and 90-99.9% aqueous phase component;

[0011] The oil phase components include modified natural oils, emulsifiers, and crosslinking agents;

[0012] The aqueous phase components include electrolytes, aqueous solvents, and initiators.

[0013] Among them, 0.1-10% can be, for example, 0.1%, 0.5%, 1%, 2%, 4%, 5%, 6%, 8% or 10%; 90-99.9% can be, for example, 90%, 92%, 94%, 95%, 96%, 98%, 99% or 99.9%.

[0014] This invention modifies natural oils by introducing reactive groups to form oil-phase prepolymers, enabling the natural oils to polymerize without leaving any toxic residues. It avoids the use of chemical raw material monomers such as acrylates, styrene, and divinylbenzene as oil phase components in high internal phase emulsion foams. The resulting high internal phase emulsion foam has 100% biocompatibility and no toxic residues.

[0015] Preferably, the modified natural oil includes (meth)acrylamide natural oil.

[0016] This invention modifies natural oils by (meth)acrylylation, introducing carbon-carbon double bonds into their molecules, enabling them to participate in free radical polymerization reactions. This allows them to serve as both the continuous phase (oil phase) of a high internal phase emulsion foam and the monomer for the polymerization reaction, thus forming a porous material.

[0017] Preferably, the emulsifier includes an edible emulsifier.

[0018] Preferably, the edible emulsifier includes any one or a combination of at least two of polyglycerol fatty acid esters, sucrose fatty acid esters, polyglycerol ricinoleate, or sorbitan monooleate.

[0019] Preferably, the crosslinking agent comprises a food-grade crosslinking agent.

[0020] Preferably, the food-grade crosslinking agent comprises food-grade pentaerythritol tetra-3-mercaptopropionate and / or food-grade trimethylolpropane triacrylate.

[0021] Preferably, the oil phase component comprises, by mass percentage, 40-97% modified natural oil, 1-20% emulsifier, and 1-40% crosslinking agent.

[0022] Among them, 40-97% can be, for example, 40%, 50%, 60%, 70%, 80%, 90% or 97%; 1-20% can be, for example, 1%, 5%, 10%, 15% or 20%; 1-40% can be, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%

[0023] Preferably, the modified natural oil is prepared by the following method, the preparation method comprising:

[0024] The modifier is mixed with natural oil and reacted to obtain the modified natural oil.

[0025] Preferably, the modifier includes acrylamide and / or methacrylamide.

[0026] Preferably, the mass ratio of the modifier to the natural oil is (0.1-0.3):1, for example, it can be 0.1:1, 0.15:1, 0.2:1, 0.25:1 or 0.3:1, etc.

[0027] Preferably, the natural oil includes any one or a combination of at least two of flaxseed oil, fish oil, or glycerin.

[0028] Preferably, the reaction temperature is 60-90℃, for example, 60℃, 70℃, 80℃ or 90℃, and the reaction time is 1-4 h, for example, 1 h, 2 h, 3 h or 4 h.

[0029] Preferably, the oil phase component further includes a thickener and / or an antioxidant.

[0030] Preferably, the thickener comprises any one or a combination of at least two of hydroxypropyl methylcellulose, beeswax, or silica.

[0031] Preferably, the antioxidant includes vitamin E.

[0032] Preferably, based on the mass percentage of the oil phase component being 100%, the oil phase component further includes 0.5-5% thickener and / or 0.5-5% antioxidant.

[0033] The range of 0.5% to 5% can be, for example, 0.5%, 1%, 2%, 3%, 4%, or 5%.

[0034] This invention compensates for the insufficient interfacial film strength of food-grade systems by adding thickeners to the oil phase components, thus preventing the oil film from breaking down under high internal phase conditions. It also prevents the oxidative degradation of the oil phase and prolongs the stability period of the emulsion and foam by adding antioxidants to the oil phase components.

[0035] In this invention, all components in the oil phase are food-grade raw materials that comply with the national food safety standard (GB2760-2024 "Standard for the Use of Food Additives"), ensuring the safety of high internal phase emulsion foam.

[0036] Preferably, the electrolyte comprises calcium chloride and / or sodium chloride.

[0037] Preferably, the aqueous solvent includes water.

[0038] Preferably, the initiator includes a photoinitiator and / or a thermal initiator.

[0039] The polymerization of high internal phase emulsion foam requires sufficient free radical density. A single initiator may lead to incomplete polymerization. This invention uses photoinitiators and thermal initiators in synergy to form a "photo-thermal dual initiation system". The photoinitiator quickly starts free radical polymerization, while the thermal initiator ensures that the deep oil phase monomers are fully cross-linked. This synergistic approach ensures that the oil phase monomers are fully cross-linked, thereby improving the porosity and mechanical strength of the high internal phase emulsion foam.

[0040] Preferably, the photoinitiator includes riboflavin.

[0041] Preferably, the thermal initiator comprises hydrogen peroxide.

[0042] The initiators used in this invention are all food-grade raw materials that comply with national food safety standards, avoiding the risks of system instability and toxic residues caused by traditional chemical initiators, and ensuring the integrity of the emulsion structure and the safety of high internal phase emulsion foam during the polymerization process.

[0043] Preferably, the aqueous phase component comprises, by mass percentage, 0.2-40% electrolyte, 50-90% aqueous solvent, and 0.001-10% initiator.

[0044] Among them, 0.2-40% can be, for example, 0.2%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%; 50-90% can be, for example, 50%, 60%, 70%, 80%, or 90%; 0.001-10% can be, for example, 0.001%, 0.005%, 0.01%, 0.05%, 1%, 2%, 4%, 5%, 6%, 8%, or 10%.

[0045] Preferably, the aqueous phase component further includes a biocompatibility agent.

[0046] Preferably, the biocompatibility agent includes gelatin and / or collagen.

[0047] Preferably, the aqueous phase component, based on a mass percentage of 100%, further includes 0.5-5% of a biocompatibility agent, such as 0.5%, 1%, 2%, 3%, 4%, or 5%.

[0048] In this invention, all components in the aqueous phase are food-grade raw materials that comply with the national food safety standard (GB2760-2024 "Standard for the Use of Food Additives"), ensuring the safety of high internal phase emulsion foam.

[0049] In a second aspect, the present invention provides a method for preparing a high internal phase emulsion foam as described in the first aspect, the method comprising:

[0050] (1) Mix the components of the oil phase component to obtain the oil phase component;

[0051] The components of the aqueous phase are mixed to obtain the aqueous phase composition;

[0052] (2) The aqueous phase component and the oil phase component are mixed to obtain the high internal phase emulsion;

[0053] (3) The high internal phase emulsion obtained in step (2) is solidified to obtain the high internal phase emulsion foam.

[0054] Preferably, the mixing temperature in step (2) is 40-80℃, for example, 40℃, 50℃, 60℃, 70℃ or 80℃, and the mixing time is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0055] Preferably, in step (1), the mixing temperature of the components of the oil phase is 20-60℃, for example, 20℃, 30℃, 40℃, 50℃ or 60℃, and the mixing time is 10-30 min, for example, 10 min, 15 min, 20 min, 25 min or 30 min.

[0056] Preferably, in step (1), the components of the oil phase are mixed under stirring.

[0057] Preferably, the stirring rate during the mixing of the components in the oil phase is 100-300 rpm, for example, 100 rpm, 150 rpm, 200 rpm, 250 rpm or 300 rpm.

[0058] Preferably, in step (1), the mixing temperature of the components of the aqueous phase is 20-90℃, for example, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃ or 90℃, and the mixing time is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0059] Preferably, in step (1), the components of the aqueous phase are mixed under stirring.

[0060] Preferably, the stirring rate during the mixing of the components in the aqueous phase is 100-200 rpm, for example, 100 rpm, 150 rpm, or 200 rpm.

[0061] Preferably, the mixing in step (2) is carried out under stirring.

[0062] Preferably, the stirring rate is 200-1500 rpm, for example, 200 rpm, 500 rpm, 1000 rpm or 1500 rpm.

[0063] Preferably, the mixing in step (2) involves adding the aqueous phase component dropwise to the oil phase component.

[0064] Preferably, the dripping rate is 20-300 mL / min, for example, it can be 20 mL / min, 50 mL / min, 100 mL / min, 150 mL / min, 200 mL / min, 250 mL / min or 300 mL / min, etc.

[0065] Preferably, the mixing in step (2) is performed under ultrasound.

[0066] Preferably, the frequency of the ultrasound is 20-40 kHz, for example, it can be 20 kHz, 25 kHz, 30 kHz, 35 kHz or 40 kHz.

[0067] Preferably, step (2) further includes a homogenization step after mixing.

[0068] Preferably, the temperature of the homogenization step is 40-60℃, for example, 40℃, 45℃, 50℃, 55℃ or 60℃, and the time of the homogenization step is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0069] Preferably, the homogenization step is carried out under stirring.

[0070] Preferably, the stirring rate in the homogenization step is 800-1200 rpm, for example, 800 rpm, 900 rpm, 1000 rpm, 1100 rpm or 1200 rpm.

[0071] Preferably, the homogenization step is performed under ultrasound.

[0072] Preferably, the frequency of the ultrasound in the homogenization step is 20-40 kHz, for example, it can be 20 kHz, 25 kHz, 30 kHz, 35 kHz or 40 kHz.

[0073] Preferably, the curing in step (3) includes sequential light curing and heat curing steps.

[0074] Preferably, the photocuring is performed by irradiation with ultraviolet light.

[0075] Preferably, the intensity of the ultraviolet light is 50-80 mW / cm². 2 For example, it could be 50 mW / cm 2 60 mW / cm 2 70mW / cm 2 Or 80 mW / cm 2 wait.

[0076] Preferably, the photocuring time is 5-10 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0077] Preferably, the heat curing temperature is 60-80℃, for example, 60℃, 65℃, 70℃, 75℃ or 80℃, and the heat curing time is 1-2 h, for example, 1 h, 1.2 h, 1.4 h, 1.5 h, 1.6 h, 1.8 h or 2 h.

[0078] Preferably, the curing process in step (3) further includes a purification step and a drying step.

[0079] Preferably, the purification step includes squeezing and washing.

[0080] Preferably, the drying step includes, but is not limited to, any one or a combination of at least two of the following: heat drying, microwave drying, vacuum dehydration, or compression drying.

[0081] Preferably, the temperature of the heating and drying step is 60-200℃, for example, it can be 60℃, 80℃, 100℃, 120℃, 140℃, 150℃, 160℃, 180℃ or 200℃.

[0082] In the preparation process of high internal phase emulsion foam provided by the present invention, the aqueous phase component is slowly added dropwise to the oil phase component for mixing, and then a high shear homogenization and ultrasonic oscillation emulsification process is adopted. This can accurately control the dispersion particle size of the aqueous phase component, avoid droplet aggregation caused by the rapid addition of the aqueous phase component in the high internal phase system, and the ultrasonic oscillation can further refine the droplets, improve the uniformity of oil-water interface contact, enhance the stability of the emulsion, and ultimately ensure the foam porosity and liquid absorption.

[0083] Thirdly, the present invention provides an application of the high internal phase emulsion foam as described in the first aspect in medical dressings, drug-carrying sustained-release carriers, short-term implantable materials, and daily chemical hygiene products.

[0084] The high internal phase emulsion porous foam provided by this invention can also be used in the field of sanitary napkins, dressings, and other daily chemical hygiene products. Using one or more layers of high internal phase emulsion porous foam material with the same or different pore sizes as the core of sanitary napkins, dressings, and other daily chemical hygiene products, its high porosity, high connectivity, and controllable pore size enable it to absorb, guide, lock in water, prevent backflow, or slowly release liquids such as water, menstrual blood, blood, body fluids, and nutrients, giving the product excellent properties such as thinness, dryness, long-lasting effect, and slow release.

[0085] Compared with the prior art, the present invention has at least the following beneficial effects:

[0086] (1) The present invention uses food-grade raw materials through synergistic design. All raw materials are food-grade and meet the requirements of GB2760-2024 "Standard for Use of Food Additives". The resulting high internal phase emulsion foam has high stability and high foam functionality.

[0087] (2) The high internal phase emulsion foam provided by the present invention can be used as a medical dressing for contact wounds / mucosa, a drug-carrying sustained-release carrier and a short-term implantable material. It can achieve 100% biocompatibility in medical scenarios and has no toxic residues, solving the industry pain points of poor biocompatibility and high residual toxicity risk caused by the reliance on chemical raw materials in traditional medical materials. Attached Figure Description

[0088] Figure 1 This is a photograph of the high internal phase emulsion provided in Example 1 of the present invention under an optical microscope, with a scale bar of 300 μm;

[0089] Figure 2 This is a scanning electron microscope image of the high internal phase emulsion foam provided in Example 1 of the present invention, with a scale bar of 50 μm;

[0090] Figure 3 This is a scanning electron microscope image of the high internal phase emulsion foam provided in Comparative Example 1 of the present invention, with a scale bar of 50 μm. Detailed Implementation

[0091] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0092] The specific information of the materials used in the following specific embodiments of the present invention is as follows:

[0093] Modified natural oil A, the modified natural oil A used in the following examples and comparative examples, was prepared by the following method, which includes:

[0094] Methacrylamide (purchased from Sigma-Aldrich) and flaxseed oil (purchased from Aladdin) were mixed at a mass ratio of 0.2:1 and reacted at 70°C for 2 h to obtain the modified natural oil A.

[0095] Modified natural oil B, and the modified natural oil A used in the following examples and comparative examples were all prepared by the following preparation method, which includes:

[0096] Acrylamide (purchased from Sigma-Aldrich) and glycerol (purchased from Aladdin) were mixed at a mass ratio of 0.2:1 and reacted at 70°C for 2 h to obtain the modified natural oil B.

[0097] Emulsifier, food-grade polyglycerol fatty acid ester, purchased from BASF;

[0098] Crosslinking agent, food-grade pentaerythritol tetra-3-mercaptopropionate, purchased from Aladdin;

[0099] Thickener, hydroxypropyl methylcellulose, purchased from Aladdin;

[0100] Antioxidant, Vitamin E, purchased from Aladdin.

[0101] Examples 1-6

[0102] Examples 1-6 provide a high internal phase emulsion foam and its preparation method, respectively. The formulations of each component in the high internal phase emulsion foam are shown in Table 1 (the amounts of each component in Table 1 are all mass percentages), where "--" indicates that the component was not added.

[0103] The preparation method includes:

[0104] (1) Mix the components of the oil phase at 50°C and 200 rpm for 20 min to obtain the oil phase component;

[0105] The aqueous phase components were mixed at 50°C and 150 rpm for 8 min to obtain the aqueous phase components.

[0106] (2) The aqueous phase component was added dropwise to the oil phase component at a rate of 100 mL / min, and then mixed at 50℃, 30 kHz, and 1000 rpm for 8 min. After mixing, the mixture was homogenized at 50℃, 30 kHz, and 1000 rpm for 8 min to obtain the high internal phase emulsion.

[0107] (3) The high internal phase emulsion was subjected to ultraviolet light (365 nm, 60 mW / cm²) before being exposed to ultraviolet light. 2 The emulsion was cured by light under a light intensity of 8 min, then heat-cured at 70℃ for 1.5 h, and then purified and dried to obtain the high internal phase emulsion foam.

[0108] Table 1

[0109]

[0110] Example 7

[0111] This embodiment provides a high internal phase emulsion foam, which differs from Embodiment 1 in that the food-grade polyglycerol fatty acid ester emulsifier is replaced in equal amounts with food-grade Span 80 (polyglycerol fatty acid ester-free, purchased from Croda, UK).

[0112] The microstructure of the high internal phase emulsion provided in Example 1 was characterized using an optical microscope (Olympus BX53). The characterization photographs are shown below. Figure 1 As shown, the scale bar is 300 μm. From Figure 1 It can be seen that the high internal phase emulsion particles provided in Example 1 are uniform and there is no obvious emulsion droplet aggregation phenomenon.

[0113] This invention uses field emission scanning electron microscopy (TESCAN MIRA3) to characterize the microstructure of the high internal phase emulsion foam provided in Example 1. The SEM results are as follows: Figure 2 As shown, the scale bar is 50 μm. From Figure 2 It can be seen that the high internal phase emulsion foam provided in Example 1 has a porous structure with interconnected pores, high porosity, and uniform pore structure. This porous structure contributes to the high liquid absorption of the high internal phase emulsion foam.

[0114] Comparative Example 1

[0115] This comparative example provides a high internal phase emulsion foam, which differs from Example 1 in that the food-grade polyglycerol fatty acid ester emulsifier is replaced in equal amounts with chemical-grade Span 80 (unpurified, purchased from Jiangsu Haian Petrochemical).

[0116] This invention uses field emission scanning electron microscopy (TESCAN MIRA3) to characterize the microstructure of the high internal phase emulsion foam provided in Comparative Example 1. The SEM results are as follows: Figure 3As shown, the scale bar is 50 μm. From Figure 3 It can be seen that although the high internal phase emulsion foam provided by Comparative Example 1 also has a porous structure, its porosity is poor, the pore structure is uneven, and the edges of the pore structure are not clear.

[0117] Comparative Example 2

[0118] This comparative example provides a high internal phase emulsion foam, which differs from Example 1 in that the modified natural oil A is replaced in equal amounts with unmodified linseed oil (purchased from Aladdin).

[0119] Comparative Example 3

[0120] This comparative example provides a commercially available medical alginate dressing (purchased from Winner Medical's alginate dressing).

[0121] Test methods

[0122] The high internal phase emulsions and high internal phase emulsion foams prepared in the examples and comparative examples were subjected to the following performance tests:

[0123] Emulsion stability: Place the high internal phase emulsion in a sealed container and let it stand at 25°C for 24 h, then observe whether stratification or water separation occurs;

[0124] Compression modulus test:

[0125] The compressive modulus was tested using an MTS universal tensile tester. The high internal phase emulsion foam was cut into cubic samples of 10 mm × 10 mm × 10 mm and compressed at 25℃ and a compression rate of 1 mm / min. The compressive modulus was extracted from the linear segment of the stress-strain curve, and the test results were taken as the average value of three parallel samples.

[0126] Porosity test:

[0127] Using the liquid displacement method, the dried high internal phase emulsion foam (m1) was weighed, then immersed in anhydrous ethanol until saturated. After removal, the surface ethanol was wiped dry and weighed (m2). Porosity P = (m2 - m1) / (ρ 乙醇 × V 泡沫 ) × 100%.

[0128] Water absorption performance test:

[0129] According to the water absorption ratio test method in GB / T 8939-2018;

[0130] Weigh the high internal phase emulsion foam sample (mass before absorption) using a balance with a sensitivity of 0.01 g. Immerse the sample in deionized water at (23±1)℃ for 60 s, then remove the sample from the water surface and hang it vertically for 90 s. Weigh the sample after water absorption (mass after absorption). Water absorption ratio = (mass after absorption - mass before absorption) / mass before absorption.

[0131] Water retention performance test:

[0132] Suspend the water-saturated foam and place it at 25℃ and 50% relative humidity for 2 hours. Measure the weight of the remaining water. The water retention rate is calculated as (weight of remaining water / weight of saturated water absorption) × 100%, and the water retention rate is required to be ≥80%.

[0133] The test results are shown in Table 2 below:

[0134] Table 2

[0135]

[0136] The test results show that:

[0137] (1) As can be seen from Examples 1 to 7, the high internal phase emulsion foam prepared by the present invention through the synergistic design of food-grade raw materials has high stability and high foam functionality. The emulsion does not stratify after standing for 24 hours, the porosity can reach 76-85%, the compression modulus can reach 0.9-1.5 MPa, the liquid absorption ratio can reach 20-28, and the water retention rate can reach 83-90%. Moreover, the high internal phase emulsion foam is 100% biocompatible and has no toxic residues in medical settings.

[0138] (2) As can be seen from Examples 1 and 4-5, the present invention can ensure that the oil phase monomers are fully cross-linked through the technical solution of photocuring and thermal curing, thereby improving the porosity and mechanical strength of the foam.

[0139] (3) As can be seen from Examples 1 and 6, the present invention compensates for the deficiency of the interfacial film strength of the food-grade system by adding a thickener to the oil phase component, and prevents the problem of oil film rupture under high internal phase.

[0140] (4) As can be seen from Examples 1 and 7, food-grade Span 80 has a low HLB value (hydrophilic-lipophilic balance value) and poor emulsification effect, resulting in a low porosity of the high internal phase emulsion foam.

[0141] (5) As can be seen from Example 1 and Comparative Example 1, the present invention replaces the food-grade emulsifier with unrefined chemical-grade Span 80. The core purpose is to verify the necessity of the food-grade emulsifier for the safety, stability, and functionality of the product. The results show that the chemical-grade emulsifier causes the emulsion to separate within 24 hours, and the foam porosity drops to 58% (far lower than 82% in Example 1), and there is a risk of impurity residue. Moreover, in the high internal phase emulsion foam formulation provided by the present invention, the food-grade emulsifier can form a uniform and stable oil-water interface film, ensuring that the emulsion does not separate and the foam has high porosity, while avoiding toxic residue. The use of food-grade raw materials is the basis for the present invention to achieve the biocompatibility and functional requirements of medical scenarios, directly solving the safety pain points of traditional chemical raw material systems.

[0142] (6) As can be seen from Example 1 and Comparative Example 3, the present invention uses unmodified linseed oil to replace the methacrylamide-modified natural oil A in Example 1, aiming to verify the innovative value of natural oil modification. The results show that the use of unmodified oil reduced the compressive modulus of the high internal phase emulsion foam to 0.9 MPa (25% lower than in Example 1) and the liquid absorption ratio to 18 (28% lower than in Example 1). This indicates that unmodified natural oil cannot participate in polymerization due to the lack of carbon-carbon double bonds, resulting in low foam crosslinking density, insufficient mechanical strength, and uneven cell structure. Modification treatment endows natural oil with polymerization ability, which not only preserves the safety of raw materials but also constructs a framework that supports the high mechanical properties and high liquid absorption of the high internal phase emulsion foam, filling the technical gap that food-grade raw materials cannot form functional porous structures.

[0143] (7) As can be seen from Example 1 and Comparative Example 4, Comparative Example 4 uses commercially available medical alginate dressings as a control, aiming to benchmark against existing commercial products and verify the technical superiority of the present invention. The comparison shows that the present invention has an absorption rate of 25 (67% higher than the commercially available 15) and a water retention rate of 88% (17% higher than the commercially available 75%), and the use of all food-grade raw materials allows for short-term implantation without the risk of chemical adhesive residue. The conclusion confirms that the present invention not only meets medical safety standards but also significantly surpasses commercially available dressings in its core functions (absorption and water retention), solving the problems of insufficient absorption and poor water retention in existing products.

[0144] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A high internal phase emulsion foam, characterized in that, The raw materials for preparing the high internal phase emulsion foam include, by mass percentage, 0.1-10% oil phase component and 90-99.9% aqueous phase component; The oil phase components include modified natural oils, emulsifiers, and crosslinking agents; The aqueous phase components include electrolytes, aqueous solvents, and initiators.

2. The high internal phase emulsion foam according to claim 1, characterized in that, The modified natural oils include (meth)acrylamide natural oils; Preferably, the emulsifier includes an edible emulsifier; Preferably, the edible emulsifier includes any one or a combination of at least two of polyglycerol fatty acid esters, sucrose fatty acid esters, polyglycerol ricinoleate, or sorbitan monooleate. Preferably, the crosslinking agent comprises a food-grade crosslinking agent; Preferably, the food-grade crosslinking agent comprises food-grade pentaerythritol tetra-3-mercaptopropionate and / or food-grade trimethylolpropane triacrylate; Preferably, the oil phase component comprises, by mass percentage, 40-97% modified natural oil, 1-20% emulsifier, and 1-40% crosslinking agent.

3. The high internal phase emulsion foam according to claim 1 or 2, characterized in that, The modified natural oil is prepared by the following method, the preparation method comprising: The modifier is mixed with natural oil and reacted to obtain the modified natural oil; Preferably, the modifier includes acrylamide and / or methacrylamide; Preferably, the mass ratio of the modifier to the natural oil is (0.1-0.3):1; Preferably, the natural oil includes any one or a combination of at least two of flaxseed oil, fish oil, or glycerin; Preferably, the reaction temperature is 60-90℃ and the reaction time is 1-4 h.

4. The high internal phase emulsion foam according to any one of claims 1-3, characterized in that, The oil phase component also includes thickeners and / or antioxidants; Preferably, the thickener comprises any one or a combination of at least two of hydroxypropyl methylcellulose, beeswax, or silica; Preferably, the antioxidant includes vitamin E; Preferably, based on the mass percentage of the oil phase component being 100%, the oil phase component further includes 0.5-5% thickener and / or 0.5-5% antioxidant.

5. The high internal phase emulsion foam according to any one of claims 1-4, characterized in that, The electrolyte includes calcium chloride and / or sodium chloride; Preferably, the aqueous solvent includes water; Preferably, the initiator includes a photoinitiator and / or a thermal initiator; Preferably, the photoinitiator includes riboflavin; Preferably, the thermal initiator comprises hydrogen peroxide; Preferably, the aqueous phase component comprises, by mass percentage, 0.2-40% electrolyte, 50-90% aqueous solvent, and 0.001-10% initiator.

6. The high internal phase emulsion foam according to any one of claims 1-5, characterized in that, The aqueous phase component also includes a biocompatibility agent; Preferably, the biocompatibility agent includes gelatin and / or collagen; Preferably, the aqueous phase component, with a mass percentage of 100%, further includes 0.5-5% biocompatibility.

7. A method for preparing a high internal phase emulsion foam as described in any one of claims 1-6, characterized in that, The method for preparing the high internal phase emulsion foam includes: (1) Mix the components of the oil phase component to obtain the oil phase component; The components of the aqueous phase are mixed to obtain the aqueous phase composition; (2) The aqueous phase component and the oil phase component are mixed to obtain the high internal phase emulsion; (3) The high internal phase emulsion obtained in step (2) is solidified to obtain the high internal phase emulsion foam.

8. The method for preparing high internal phase emulsion foam according to claim 7, characterized in that, The mixing temperature in step (2) is 40-80℃, and the mixing time is 5-10 min; Preferably, the mixing in step (2) is carried out under stirring; Preferably, the stirring rate is 200-1500 rpm; Preferably, the mixing in step (2) involves adding the aqueous phase component dropwise to the oil phase component; Preferably, the dropping rate is 20-300 mL / min; Preferably, the mixing in step (2) is performed under ultrasound; Preferably, the frequency of the ultrasound is 20-40 kHz; Preferably, the mixing in step (2) further includes a homogenization step; Preferably, the temperature of the homogenization step is 40-60℃, and the homogenization time is 5-10 min; Preferably, the homogenization step is carried out under stirring; Preferably, the stirring rate in the homogenization step is 800-1200 rpm; Preferably, the homogenization step is performed under ultrasound; Preferably, the frequency of the ultrasound in the homogenization step is 20-40 kHz.

9. The method for preparing high internal phase emulsion foam according to claim 7 or 8, characterized in that, The curing process described in step (3) includes sequential light curing and heat curing; Preferably, the photocuring is performed by ultraviolet light irradiation; Preferably, the intensity of the ultraviolet light is 50-80 mW / cm². 2 ; Preferably, the photocuring time is 5-10 min; Preferably, the thermosetting temperature is 60-80℃ and the thermosetting time is 1-2 h.

10. The application of a high internal phase emulsion foam as described in any one of claims 1-6 in medical dressings, drug-carrying sustained-release carriers, short-term implantable materials, and daily chemical hygiene products.

Images