CN115215961B - Double-emulsifier-based water-absorbing foam and preparation method thereof - Google Patents

Double-emulsifier-based water-absorbing foam and preparation method thereof Download PDF

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CN115215961B
CN115215961B CN202210951600.0A CN202210951600A CN115215961B CN 115215961 B CN115215961 B CN 115215961B CN 202210951600 A CN202210951600 A CN 202210951600A CN 115215961 B CN115215961 B CN 115215961B
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water
phase system
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foam
oil phase
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CN115215961A (en
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樊李红
代志寅
褚莹莹
谢益思
张国星
王梦婷
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Wuhan University of Technology WUT
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1808—C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/12—Polymerisation in non-solvents
    • C08F2/16—Aqueous medium
    • C08F2/22—Emulsion polymerisation
    • C08F2/24—Emulsion polymerisation with the aid of emulsifying agents
    • C08F2/30—Emulsion polymerisation with the aid of emulsifying agents non-ionic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/16—Halogen-containing compounds
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    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/22—Expanded, porous or hollow particles
    • C08K7/24—Expanded, porous or hollow particles inorganic
    • C08K7/26—Silicon- containing compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/16—Halogen-containing compounds
    • C08K2003/162—Calcium, strontium or barium halides, e.g. calcium, strontium or barium chloride
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C08K2003/2227—Oxides; Hydroxides of metals of aluminium
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C08K2003/2296—Oxides; Hydroxides of metals of zinc
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
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    • C08K2201/011—Nanostructured additives

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Abstract

The invention discloses a double-emulsifier-based water-absorbing foam and a preparation method thereof, wherein the water-absorbing foam is a mixture of a water phase system and an oil phase system and is obtained by emulsion polymerization under the action of an initiator solution; the water phase system is electrolyte water solution with mass fraction of 0.5-3%; the oil phase system is a mixture of 50-90% of acrylic ester monomer, 5-20% of ethylene monomer, 0.1-5% of cross-linking agent and 4-30% of double emulsifying agent according to mass fraction, and the double emulsifying agent is a mixture of lipophilic surfactant and nano metal particles; the mass ratio of the water phase system to the oil phase system is (10-20): 1. The oil phase system of the invention adopts double emulsifying agents, effectively improves the stability of emulsion and the strength of foam, and the water-absorbing foam obtained after polymerization and drying has uniform dispersion of foam cells, and the average water absorption and water retention capacity of the water-absorbing foam is not less than 20g/g.

Description

Double-emulsifier-based water-absorbing foam and preparation method thereof
Technical Field
The invention belongs to the field of water-absorbing materials, and particularly relates to a water-absorbing foam based on a double emulsifier and a preparation method thereof.
Background
The acrylic ester water-absorbing material is widely applied to the field of sanitary articles due to excellent water absorption and water retention property, and the water-absorbing material applied to the fields of diaper, female sanitary articles and the like nowadays mainly consists of granular acrylic ester. It has a "doughy effect" after water absorption, causing discomfort and also causing excessive absorption in the middle and no water absorption at the edges. Therefore, the development of the water-absorbing foam based on acrylic esters has important significance for improving the water absorption and water retention capacity of materials and promoting commercial application.
The research shows that the existing high internal phase emulsion constructed by using the emulsifier and the acrylic ester material as the monomers has the problem of poor stability, and the stability of the emulsion can be destroyed under the conditions of standing, stirring rotation speed reduction, temperature rise or polymerization, and the like, so that the oil-water separation conditions of different degrees are caused, and the water absorption and water retention properties of the foam are further influenced. Particularly, when an initiator is added to carry out emulsion polymerization, 10-40 wt% of oil-water separation phenomenon can be caused, so that the foam water absorption and water retention capacity is greatly reduced, and the oil-water separation phenomenon of 30-80 wt% can also occur after a foam modifier is added. The stability of the emulsion severely affects the foam performance, and the commercial process and modification studies.
Disclosure of Invention
The invention aims to overcome the technical defects, and provides a double-emulsifier-based water-absorbing foam and a preparation method thereof, which solve the technical problem that the prepared water-absorbing foam has poor water absorbing and water retaining capacities due to unstable emulsion in the prior art.
In order to achieve the technical purpose, the technical scheme of the double-emulsifier-based water-absorbing foam is as follows:
the water-absorbing foam is a mixture of a water phase system and an oil phase system and is obtained by emulsion polymerization under the action of an initiator solution; the water phase system is electrolyte water solution with mass fraction of 0.5-3%; the oil phase system is a mixture of 50-90% of acrylic ester monomer, 5-20% of ethylene monomer, 0.1-5% of cross-linking agent and 4-30% of double emulsifying agent according to mass fraction, and the double emulsifying agent is a mixture of lipophilic surfactant and nano metal particles; the mass ratio of the water phase system to the oil phase system is (10-20): 1.
Further, the composition of the oil phase system is: 60 to 70 weight percent of acrylic monomer, 7 to 15 weight percent of ethylene monomer, 0.1 to 2 weight percent of cross-linking agent and 10 to 15 weight percent of double emulsifying agent.
Further, the acrylic monomer is isooctyl acrylate, propyl acrylate or butyl acrylate, the vinyl monomer is divinylbenzene, vinylphenol, vinylaniline or vinylbenzyl alcohol, and the crosslinking agent is ethylene glycol dimethacrylate.
Further, the mass ratio of the lipophilic surfactant to the nano metal particles is (5-7): 1.
Further, the lipophilic surfactant is span-20, span-40, span-60, span-80 or span-85; the nanometer metal particles are nanometer titanium dioxide, nanometer silicon dioxide, nanometer zinc oxide, nanometer aluminum oxide or nanometer ferric oxide.
Further, the electrolyte is anhydrous calcium chloride; the initiator solution is prepared by dissolving an initiator and calcium chloride in water, and the mass ratio of the initiator to the calcium chloride to the water is (0.6-1.2): (0.1-0.15) 10; the mass ratio of the initiator solution to the oil phase system is (0.7-0.9): 1.
Further, the initiator is dicumyl peroxide, di-tert-butyl cumene peroxide, di-tert-butyl peroxide or benzoyl peroxide.
The technical scheme of the preparation method of the water-absorbing foam based on the double emulsifying agent is as follows: the method comprises the following steps: adding the water phase system into the oil phase system, stirring until flocculent substances appear, dripping initiator solution, stirring uniformly after dripping, performing emulsion polymerization, and drying the emulsion polymerization product to obtain the water-absorbing foam.
Further, the water phase system is added into the oil phase system at one time, and the stirring speed is 600-1000 RPM; and (3) dropwise adding an initiator solution, and regulating the rotating speed to 1500-2500RPM.
Further, the temperature of the emulsion polymerization is 70-90 ℃ and the time is 6-8 h.
Compared with the prior art, the invention has the beneficial effects that:
the double-emulsifier is selected in the oil phase system, wherein the surfactant has stronger emulsifying capacity on the water-in-oil emulsion, and meanwhile, the nano metal particles for promoting the dispersion of the emulsion are added, so that experiments show that the nano metal particles have the effects of promoting the emulsion polymerization and enhancing the crosslinking of the monomer, and the stability of the emulsion and the strength of the foam are effectively improved. The emulsion prepared by the invention has excellent stability, and no obvious oil-water separation phenomenon occurs under the conditions of reduced stirring rotation speed, heating or polymerization; the water-absorbing foam obtained after polymerization and drying has uniformly dispersed foam cells and pore diameter of 5-10 mu m; the water-absorbing foam has good toughness and strength, and the average water-absorbing and water-retaining capacities are not lower than 20g/g.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
The invention provides a double-emulsifier-based high internal phase emulsion with good stability, and the stability is still good after a modifier is added in the emulsion, so that the prepared water-absorbing foam has strong water absorbing and water retaining capacity.
The preparation method of the water-absorbing foam comprises the following steps:
s1, preparing an oil phase system: weighing 50-90 wt% of acrylic ester monomer, 5-20 wt% of ethylene monomer, 0.1-5 wt% of cross-linking agent and 4-30 wt% of double emulsifying agent, and uniformly stirring.
S2, preparing a water phase system: an aqueous electrolyte solution with a mass fraction of 0.5-3 wt% is prepared.
S3, preparing an initiator: an initiator solution with the mass fraction of 5-15 wt% is prepared.
S4, adding the water phase system into the oil phase system at one time, wherein the stirring speed is 600-1000RPM, stirring for 15-20 min, and the mass ratio of the water phase to the oil phase is 10-20: 1.
s5, after uniformly stirring, slowly dripping an initiator solution when flocculent substances appear (before emulsion is sticky), wherein the mass ratio of the initiator solution to an oil phase system is (0.7-0.9): 1; the rotating speed is regulated to 1500-2500RPM. After the dripping is finished, stirring for 5 to 15 minutes. Regulating the temperature to 70-90 ℃ and carrying out emulsion polymerization for 6-8 h.
S6, drying the product at 50-70 ℃, and washing and drying to obtain the water-absorbing foam product.
In step S1, the oil phase system preferably has the following composition: 60 to 70 weight percent of acrylic monomer, 7 to 15 weight percent of ethylene monomer, 0.1 to 2 weight percent of cross-linking agent and 10 to 15 weight percent of double emulsifying agent.
In step S1, the acrylic monomer is isooctyl acrylate, propyl acrylate, or butyl acrylate. The vinyl monomer is a vinyl monomer containing benzene, and specifically is divinylbenzene, vinylphenol, vinylaniline or vinylbenzyl alcohol. The cross-linking agent is ethylene glycol dimethacrylate. The acrylic monomer and the vinyl monomer are common polymerization monomers in the field, and the purpose is to form stable emulsion with water by utilizing the property of high hydrophobicity.
As a most preferred embodiment, the acrylic monomer is isooctyl acrylate and the vinyl monomer is preferably divinylbenzene.
In step S1, the double emulsifier includes a lipophilic surfactant and nano-metal particles.
The purpose of the double emulsifying agent is to reduce the interfacial tension of each component in the mixed system and form stable emulsion. The lipophilic surfactant used in the invention is more favorable for emulsifying and dispersing monomers, and nano metal particles with the function of reducing interfacial tension are added, so that the stability of emulsion is further enhanced.
Preferably, the surfactant is span-20, span-40, span-60, span-80 or span-85. The nanometer metal particles are nanometer titanium dioxide, nanometer silicon dioxide, nanometer zinc oxide, nanometer aluminum oxide or nanometer ferric oxide, etc.
As the optimal scheme, the surfactant is span-80, and the nano metal particles are nano zinc oxide.
In step S2, the electrolyte is anhydrous calcium chloride. The electrolyte adopted by the invention is a common raw material in the field, and has wide sources and low cost; meanwhile, the addition of the electrolyte reduces the dissolution capacity of the continuous phase, inhibits the process of Ostwald ripening, and thus improves the stability of the emulsion system.
In step S3, the initiator is an oil-soluble initiator, preferably a peroxide initiator such as dicumyl peroxide, di-t-butylperoxyisopropyl benzene, di-t-butylperoxide, benzoyl peroxide, or the like.
Most preferably, the peroxide initiator is benzoyl peroxide.
In the step S3, the initiator solution contains calcium chloride, and the mass ratio of the initiator to the calcium chloride to the water in the initiator solution is (0.6-1.2): (0.1-0.15): 10. The initiator can damage the stability of emulsion after being dissolved in water and added into the system, especially the pure use of deionized water to dissolve benzoyl peroxide. A small amount of calcium chloride is added to reduce the damaging effect on the emulsion stability.
And S4, adding the water phase into the oil phase at one time, adjusting the stirring rotation speed to 600-1000RPM after adding the water phase, and increasing the rotation speed to 1500-2500RPM when the emulsion of the dropwise added initiator solution becomes viscous in the step S5. The purpose of the speed change is to avoid that the speed is too high which leads to sticking of the monomers to the walls of the container before the emulsion becomes viscous. The rotational speed is increased after the mixture is viscous, so that the monomer is dispersed more uniformly, the emulsion stability is stronger, and the foam with uniform pore size of the foam holes can be easily prepared.
In the step S5, the polymerization temperature is preferably 70-90 ℃, the polymerization rate can be accelerated by properly increasing the temperature, the polymerization time can be reduced, for example, 8 hours at 70 ℃, 7.5 hours at 80 ℃, 6 hours at 90 ℃ and the like, but the polymerization temperature cannot be too high, the phenomena of explosion polymerization, too large and uneven product pore diameters and the like are prevented, and the adverse phenomena of too slow polymerization rate and even incapacity of polymerization and the like can be caused by too low polymerization temperature.
The main mechanism analysis of the invention:
(1) According to the invention, a surfactant with stronger emulsifying capacity for water-in-oil emulsion is selected in an oil phase system, and nano metal particles for promoting emulsion dispersion are added, so that experiments show that the nano metal particles have the effects of promoting emulsion polymerization and enhancing monomer crosslinking; it effectively improves the stability of the emulsion and the strength of the foam.
(2) The invention does not need to drip raw materials for a long time, and the oil-water phase is directly mixed, so that the reaction time is greatly reduced. The emulsion with good stability is synthesized through the regulation and control of the rotating speed, and the working procedures are saved. The stability is good, the emulsion is not easy to generate oil-water separation phenomenon in the polymerization process and only generates a small amount of oil-water separation phenomenon after adding the modified substances, so that the foam formed after drying has excellent water absorption and water retention performances.
(3) According to the invention, through a specific formula, the prepared emulsion has excellent stability, and no obvious oil-water separation phenomenon occurs under the conditions of long-time standing, stirring rotation speed reduction, heating or polymerization. The water-absorbing foam obtained after polymerization and drying has uniform dispersion of cells and good toughness and strength.
The emulsion prepared by the invention has excellent stability, and the water-absorbing foam obtained after polymerization and drying is suitable for being applied to the water-absorbing fields of sanitary products and the like.
For avoiding redundancy, the main test items of the present invention are described herein:
1. internal phase volume fraction testing
After the initiator is dripped in the step S5 and stirred for 5 to 15 minutes, the water (V) on the surface of the emulsion sample is added 1 ) After being sucked, the mixture is put into a centrifuge tube and put into the centrifuge for mild centrifugation, the rotating speed is 100-120 RPM, and the centrifugation time is 3-5 min.
Then the surface water phase (V) after oil-water separation is sucked up by using a rubber head dropper 2 ) The total volume of the oil phase and the water phase is V, and the volume fraction of the internal phase is (V-V 1 -V 2 )/V×100％。
2. Cell size and diameter test
Three samples were randomly selected on the dried water-absorbent foam, and the cell and diameter sizes thereof were observed by scanning electron microscopy at 1000 times.
3. Tensile Strength test
The foam sample strength was tested using a foam tensile strength tester.
4. Test of Water absorption and Water Retention
Three 0.5g foam samples dried to constant weight were weighed at 25℃respectively, placed in three 100ml beakers, 25ml deionized water, physiological saline and artificial urine were injected into the beakers respectively, and the samples were placed therein for 10 minutes. Then taking out and weighing, removing excessive water on the foam surface during weighing, and recording the weight as M 1 、M 2 、M 3 . The average deionized water absorption rate was 2M within 10 minutes of this sample 1 g/g, average absorption physiological saline ratio of 2M 2 g/g, average artificial urine absorption rate of 2M 3 g/g。
In the water absorption test, the average water absorption of the foam was experimentally measured over 10 minutes, so this index reflects both the water absorption and the water retention.
The internal phase is composed of water, and the internal phase forms a foam pore structure after being dried. The larger the internal phase volume, the greater the water absorption retention capacity.
Water absorption mechanism: firstly, hydrophilic monomers on the surface of the foam; secondly, the smaller the cell size, the stronger the water absorbing and storing capacity due to the absorption and storing of the micro cell structure, for example, the cell diameter is 5-10 μm, and the water absorbing and water holding property is better than the cell diameter is 5-25 μm.
The invention is further illustrated by the following specific examples.
Example 1
1. Preparation of absorbent foam based on double emulsifiers
(1) Preparing an oil phase system, weighing 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate, 3.0g of span-80 and 0.5g of nano zinc oxide, and uniformly stirring to obtain the oil phase system.
(2) Preparing an aqueous phase system, weighing 1.5g of anhydrous calcium chloride and 120g of deionized water, and uniformly stirring to obtain the aqueous phase system for later use.
(3) Preparing an initiator solution, weighing 0.9g of benzoyl peroxide, 0.125g of anhydrous calcium chloride and 10g of deionized water, and uniformly stirring to obtain the initiator solution for later use.
(4) The oil phase system thus prepared was added to a 1000ml beaker, stirring was started, and the aqueous phase system uniformly stirred was added to the beaker at once at a stirring speed of 800RPM. When the flocculent substance appears, slowly dripping the initiator, and adjusting the rotating speed to 2000RPM. After the completion of the dropwise addition, stirring was carried out for another 5 minutes.
(5) The stirred high internal phase emulsion was sealed and polymerized in a water bath at 70℃for 8h.
(6) And (5) after molding and curing, placing the molded and cured product into a blast drying oven and drying the molded and cured product at 60 ℃ for 12 hours. Taking out, repeatedly washing, and drying in a forced air drying oven again to constant weight.
2. Product testing
The high internal phase emulsion prepared in the embodiment has good stability. After the initiator is added dropwise, the emulsion is thick and has no oil-water separation phenomenon, and the volume fraction of the internal phase is 92.8%. No significant delamination occurred after polymerization. The tensile strength of the foam is 0.38MPa, the size of the foam cells is uniform, and the diameter is 5-10 mu m. Within 10 minutes, the average deionized water absorption rate was 25.77g/g (strong water absorption and retention capacity), the average physiological saline absorption rate was 23.41g/g, and the average artificial urine absorption rate was 21.37g/g.
Example 2
The difference from example 1 is that: the nano zinc oxide is replaced by nano silicon dioxide.
Namely, the oil phase system preparation in the step (1) comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate, 3.0g of span-80 and 0.5g of nano silicon dioxide are weighed. Other conditions were the same as in example 1.
The prepared emulsion has good stability. After the initiator is added dropwise, the emulsion is thick without oil-water separation; no significant delamination occurred after polymerization. The diameter of the cells of the obtained water-absorbing foam is 5-10 mu m. The specific test results are shown in Table 1.
Example 3
The difference from example 1 is that: the nano zinc oxide is replaced by nano aluminum oxide.
The prepared emulsion has good stability. After the initiator is added dropwise, the emulsion is thick without oil-water separation; no significant delamination occurred after polymerization. The diameter of the cells of the obtained water-absorbing foam is 5-10 mu m. The specific test results are shown in Table 1.
TABLE 1 results of product testing of examples 1-3
The main influence on the experiment is reflected in the diameter of the particles, so the nano-scale metal particles are adopted, and the diameters of the obtained cells are not greatly different and are 5-10 mu m; the invention is applicable to nano-metal particle nano-titanium dioxide, nano-silicon dioxide, nano-zinc oxide, nano-aluminum oxide or nano-iron oxide, etc.
As can be seen from Table 1, examples 1-3, in which the types of the metal nanoparticles were changed, the internal phase volume fraction of the resulting water-absorbent foam was 87.8 to 92.8%, the tensile strength of the foam was 0.34 to 0.38MPa, the average deionized water absorption rate was 22.48 to 25.77g/g, the average physiological saline absorption rate was 19.88 to 23.41g/g, and the average artificial urine absorption rate was 17.65 to 21.37g/g; the best effect is nano zinc oxide, so nano zinc oxide is preferred for the nano metal particles of the invention.
Example 4
The difference from example 3 is that: polyvinyl alcohol (nano alumina + polyvinyl alcohol) is added in the oil phase system.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate, 3.0g of span-80, 0.5g of nano alumina and 0.2g of polyvinyl alcohol are weighed. Other conditions were the same as in example 3.
After the polyvinyl alcohol is added as the strength modifier, the prepared emulsion is still thick, but a small amount of oil-water separation phenomenon occurs, and the stability is good. The internal phase volume fraction after polymerization was 83.1%. The tensile strength of the foam is 0.41MPa, and the diameter of the foam cells is 5-10 mu m. The average deionized water absorption rate was 27.32g/g, the average physiological saline absorption rate was 26.44g/g, and the average artificial urine absorption rate was 23.67g/g within 10 minutes. The specific test results are shown in Table 2.
Example 5
The difference from example 1 is that: 0.2g of polyvinyl alcohol (nano zinc oxide + polyvinyl alcohol) is added into the oil phase system.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate, 3.0g of span-80, 0.5g of nano zinc oxide and 0.2g of polyvinyl alcohol are weighed. Other conditions were the same as in example 3.
The specific test results are shown in Table 2.
Table 2 comparison of test results for example 1 and example 4
In the embodiment 4, the polyvinyl alcohol is added on the basis of the embodiment 3, and the span-80 and the nano metal particles are used as double emulsifying agents, so that the emulsion still keeps better stability after the polyvinyl alcohol is added as a modifier, and only a small amount of oil-water separation phenomenon occurs, which is shown by slightly reducing the volume fraction of the internal phase; although the decrease in internal phase volume reduces water absorption, the addition of polyvinyl alcohol increases the strength of the foam, effectively preventing the collapse of the foam during the drying process, and thus the overall foam exhibits better water absorption and retention.
In comparison with the nano alumina and the polyvinyl alcohol in the embodiment 4 and the embodiment 5, the nano zinc oxide and the polyvinyl alcohol are adopted in the embodiment 5 to be matched, so that the overall performance is improved, and particularly the water absorption foam prepared in the embodiment 5 is high in average water absorption and strong in water absorption and water retention capacity.
Example 6
The resulting products were each tested under the same conditions as in example 1 except that divinylbenzene was replaced with vinylphenol, vinylbenzyl alcohol and styrene, and the results are shown in Table 3 below.
TABLE 3 Water absorbing foam Properties from different ethylene monomers
As shown in Table 3, the ethylene monomers adopted by the invention have better water absorption and water retention capacities; because vinylphenol and vinylbenzyl alcohol contain hydrophilic groups, they may deteriorate the stability of the emulsion to some extent, resulting in oil-water separation, a decrease in the internal phase volume fraction and a decrease in the water absorption and retention ability, as also demonstrated by the test results in Table 3; therefore, in the reaction system of the invention, divinylbenzene, styrene and the like can be used for synergistic interaction with acrylic acid, and the divinylbenzene and the styrene are preferably used as the vinyl monomers of the invention in consideration of comprehensive performance parameters, and the styrene has a lower crosslinking degree than the divinylbenzene due to only one vinyl group, and has slightly lower performance improvement effect than the divinylbenzene, so the divinylbenzene is most preferred.
Example 7 (preparation of Water absorbing foam based on different initiators)
The difference from example 1 is that: the initiator was replaced by dicumyl peroxide and the other conditions were the same as in example 1.
Namely, the step (3) of configuring the initiator comprises the following steps: weighing 0.9g of dicumyl peroxide, 0.125g of anhydrous calcium chloride and 10g of deionized water, and uniformly stirring for later use.
Product testing was performed with different kinds of initiators: after dicumyl peroxide is used, the emulsion has no oil-water separation phenomenon, and the volume fraction of the internal phase is 91.9%. No significant delamination occurred after polymerization. The tensile strength of the foam is 0.29MPa, the size of the foam cells is uniform, and the diameter is 5-10 mu m. The average deionized water absorption rate was 20.87g/g, the average physiological saline absorption rate was 18.55g/g, and the average artificial urine absorption rate was 17.76g/g within 10 minutes. The experimental data compare the dicumyl peroxide initiation efficiency with the benzoyl peroxide under the same temperature and time conditions, so the initiator is preferably benzoyl peroxide in the invention.
Comparative example 1 (preparation of absorbent foam based on Single emulsifier)
The difference from example 1 is that: the nano zinc oxide in the oil phase system was removed, and the other conditions were the same as in example 1.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate and 3.0g of span were weighed.
The prepared emulsion has good stability. After the initiator is added dropwise, the emulsion is subjected to a small amount of oil-water separation phenomenon and is thick; delamination occurred after polymerization and the specific test results are shown in Table 4.
Comparative example 2 (preparation of absorbent foam based on Single emulsifier)
The difference from example 1 is that: span-80 was removed from the oil phase system, and the other conditions were the same as in example 1.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate and 0.5g of nano zinc oxide are weighed.
The prepared emulsion has poor stability. After the initiator was added dropwise, the emulsion underwent significant oil-water separation, and after polymerization, delamination occurred, and specific test results are shown in Table 4.
Comparative example 3 (preparation of absorbent foam based on Single emulsifier)
The difference from example 1 is that: the double emulsifier (span-80.0 g, nano zinc oxide 0.5 g) in the oil phase system was replaced with tween-80.0 g, and the other conditions were the same as in example 1.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate and 3.0g of Tween-80 were weighed.
The surfactant Tween-80 commonly used in the art is adopted as an emulsifier, serious phase separation occurs, the volume fraction of the internal phase is 12.0%, and emulsion cannot be formed. The tensile strength of the foam is 0.1MPa, and the sizes of the foam cells are different. The average deionized water absorption rate was 4.12g/g, the average physiological saline absorption rate was 2.57g/g, and the average artificial urine absorption rate was 1.82g/g within 10 minutes, and the specific test results are shown in Table 4.
Comparative example 4 (Single emulsifier + polyvinyl alcohol modification)
The difference from example 1 is that: the nano zinc oxide in the oil phase system was removed and 0.2g of polyvinyl alcohol was added, and the other conditions were the same as in example 1.
Namely, the step (1) of configuring the oil phase system comprises the following steps: 8.1g of isooctyl acrylate, 1.35g of divinylbenzene, 0.45g of ethylene glycol dimethacrylate, 3.0g of span-80 and 0.2g of polyvinyl alcohol were weighed out, and the conditions were the same as in example 1.
The specific test results are shown in Table 4.
TABLE 4 results of product testing for example 1 and comparative examples 1-2
From the test results of example 1 and comparative examples 1 to 2 in Table 4, it is understood that the use of the double emulsifier in the system of the present invention can effectively improve the stability of the emulsion, the internal phase volume fraction of the emulsion is high, the pore size of the foam is small and uniform, and the strength, water absorption and water retention properties are excellent.
As compared with span-80, the tween-80 used in the prior art in comparative example 3 can not be used as an emulsifier of the system well because the hydrophile-lipophile balance value is higher than that of span-80, and can cause obvious oil-water separation phenomenon, and the performance of the compound emulsion is obviously reduced compared with that of comparative example 1.
Comparative example 4 shows a significant decrease in performance relative to comparative example 1, demonstrating that the addition of a small amount of modifier polyvinyl alcohol in a single emulsifier system would destroy the stability of the emulsion, thus demonstrating the synergy of span-80, nano zinc oxide, and polyvinyl alcohol in example 5 of the present invention.
In summary, the invention adopts the emulsion template method to obtain the emulsion with high disperse phase coefficient and stability by using the double emulsifying agent, and the emulsion is polymerized and dried to obtain the water-absorbing foam with a space network structure, which has good strength and flexibility, uniform dispersion of cells and diameter of the cells of 5-10 mu m; the internal phase volume fraction of the obtained water-absorbing foam is 85.7-92.8%, the tensile strength of the foam is 0.34-0.43 MPa, the average deionized water absorption rate is 20.87-28.07 g/g, the average physiological saline absorption rate is 18.55-27.44 g/g, and the average artificial urine absorption rate is 17.54-23.89 g/g, and the water-absorbing foam can be applied to the water-absorbing fields of sanitary products and the like. The double emulsifying agent and the preparation method thereof effectively improve the stability of the emulsion, reduce the oil-water separation phenomenon of the emulsion in the polymerization process, and provide a feasible scheme for solving the stability of the emulsion and preparing the water-absorbing foam. The preparation process is simple and is beneficial to industrial production.
The above-described embodiments of the present invention do not limit the scope of the present invention. Any other corresponding changes and modifications made in accordance with the technical idea of the present invention shall be included in the scope of the claims of the present invention.

Claims (9)

1. A double-emulsifier-based water-absorbing foam, characterized in that the water-absorbing foam is a mixture of an aqueous phase system and an oil phase system, and is obtained by emulsion polymerization under the action of an initiator solution;
the water phase system is an electrolyte water solution with the mass fraction of 0.5-3%;
the oil phase system is a mixture of 50-90% of acrylic ester monomer, 5-20% of divinylbenzene, 0.1-5% of cross-linking agent and 4-30% of double emulsifying agent according to mass fraction, wherein the double emulsifying agent is a mixture of lipophilic surfactant and nano metal particles;
the mass ratio of the water phase system to the oil phase system is (10-20): 1;
the mass ratio of the lipophilic surfactant to the nano metal particles is (5-7) 1;
the nanometer metal particles are nanometer titanium dioxide, nanometer zinc oxide or nanometer aluminum oxide;
the initiator solution is prepared by dissolving an initiator and calcium chloride in water, wherein the mass ratio of the initiator to the calcium chloride to the water is (0.6-1.2): (0.1-0.15) 10; the mass ratio of the initiator solution to the oil phase system is (0.7-0.9): 1.
2. The double emulsifier based water absorbing foam of claim 1 wherein the oil phase system has a composition of: 60-70 wt% of acrylic monomer, 7-15 wt% of divinylbenzene, 0.1-2 wt% of cross-linking agent and 10-15 wt% of double emulsifier.
3. The dual emulsifier based absorbent foam of claim 1 wherein the acrylic monomer is isooctyl acrylate, propyl acrylate or butyl acrylate and the cross-linking agent is ethylene glycol dimethacrylate.
4. The dual emulsifier based absorbent foam of claim 1 wherein the lipophilic surfactant is span-20, span-40, span-60, span-80 or span-85.
5. The dual emulsifier based absorbent foam of claim 1 wherein the electrolyte is anhydrous calcium chloride.
6. The double emulsifier based absorbent foam according to claim 1, wherein the initiator is dicumyl peroxide, di-t-butylcumene peroxide, di-t-butyl peroxide or benzoyl peroxide.
7. A method for the preparation of a double emulsifier based absorbent foam according to any of claims 1-6, comprising the steps of: adding the water phase system into the oil phase system, stirring until flocculent substances appear, dripping initiator solution, stirring uniformly after dripping, performing emulsion polymerization, and drying the emulsion polymerization product to obtain the water-absorbing foam.
8. The preparation method of the double-emulsifier-based water-absorbing foam, according to claim 7, is characterized in that the water phase system is added into the oil phase system at one time, and the stirring speed is 600-1000 RPM; and (3) dropwise adding an initiator solution, and adjusting the rotating speed to 1500-2500RPM.
9. The method for preparing the double emulsifier-based water-absorbing foam according to claim 7, wherein the temperature of emulsion polymerization is 70-90 ℃ and the time is 6-8 h.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102391416A (en) * 2011-09-02 2012-03-28 华东理工大学 Preparation method of porous material based on inorganic nanoparticles for stabilizing high internal phase emulsion
CN103301782A (en) * 2013-06-27 2013-09-18 江南大学 Compound emulsifier with switching property
CN106190514A (en) * 2016-07-29 2016-12-07 南京凯耐思化工科技有限公司 A kind of intermetallic composite coating double nano emulsion its preparation method and application
CN109705373A (en) * 2018-12-30 2019-05-03 武汉理工大学 A kind of high-intensitive three network aqueous gel and preparation method thereof
CN110423298A (en) * 2019-07-06 2019-11-08 湖北大学 A kind of water-oil separating SiO2/ polystyrene composite porous material preparation method
CN113980344A (en) * 2021-11-10 2022-01-28 万华化学集团股份有限公司 Method for preparing open-cell foam material from ultrahigh internal phase Pickering emulsion, foam absorbing material and application thereof
CN114410045A (en) * 2022-03-09 2022-04-29 万华化学集团股份有限公司 Method for preparing bacteriostatic foam absorbing material from HIPPE, foam absorbing material and application thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102391416A (en) * 2011-09-02 2012-03-28 华东理工大学 Preparation method of porous material based on inorganic nanoparticles for stabilizing high internal phase emulsion
CN103301782A (en) * 2013-06-27 2013-09-18 江南大学 Compound emulsifier with switching property
CN106190514A (en) * 2016-07-29 2016-12-07 南京凯耐思化工科技有限公司 A kind of intermetallic composite coating double nano emulsion its preparation method and application
CN109705373A (en) * 2018-12-30 2019-05-03 武汉理工大学 A kind of high-intensitive three network aqueous gel and preparation method thereof
CN110423298A (en) * 2019-07-06 2019-11-08 湖北大学 A kind of water-oil separating SiO2/ polystyrene composite porous material preparation method
CN113980344A (en) * 2021-11-10 2022-01-28 万华化学集团股份有限公司 Method for preparing open-cell foam material from ultrahigh internal phase Pickering emulsion, foam absorbing material and application thereof
CN114410045A (en) * 2022-03-09 2022-04-29 万华化学集团股份有限公司 Method for preparing bacteriostatic foam absorbing material from HIPPE, foam absorbing material and application thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
A new type of porous Zn (II) metal-organic gel designed for effective adsorption to methyl orange dye;Mengting Wang et al.;《Colloids andSurfacesA:PhysicochemicalandEngineeringAspects》;12735(1-12) *

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