CN104250350A - Method for preparing porous polymer material with through-pore structure - Google Patents

Abstract

The invention belongs to the technical field of materials, in particular to a preparation method of a polymer porous material with a through-hole structure. In the present invention, hydrophilic inorganic nanoparticles are uniformly dispersed in water to form a hydrosol, and then a long-chain modifier is added to modify the inorganic nanoparticles; the obtained modified inorganic nanoparticles are dispersed in water, Adding monomers and initiators thereto, performing homogenization or ultrasonic treatment, to form a stable water-in-oil type high-internal phase emulsion; and obtaining a polymer porous material with a through-hole structure through a temperature-raising reaction. The preparation method of the invention is simple, the raw materials are cheap and easy to obtain, the pore diameter and channel size of the prepared polymer porous material are adjustable, and the permeability is good.

Description

A kind of preparation method of polymer porous material with through-hole structure

technical field

The invention belongs to the technical field of materials, and in particular relates to a preparation method of a porous material with a through-hole structure.

Background technique

Porous materials are a kind of materials with a network structure composed of interpenetrating or closed pores. Compared with general materials, porous materials have a higher specific surface area. This property enables them to be used as separation media, catalyst loading, cell skeletons, etc. Among them, polymer porous materials have attracted more and more attention due to their low density and easy processing.

The preparation methods of polymer porous materials mainly include supercritical fluid method, colloid template assembly method, polymer precursor template method and high internal phase emulsion template method, etc. The high internal phase emulsion template method has been widely used because of the controllable pore size and simple operation of the prepared porous materials. In order to obtain a stable high internal phase emulsion, it is usually necessary to add surfactants up to 20-30% of the continuous phase content. After polymerization, the removal of these surfactants and the higher price of some surfactants will inevitably increase the porousness of the prepared polymer. The cost of materials. The almost irreversible adsorption behavior of solid particles at the two-phase interface makes it possible to obtain a stable high internal phase emulsion even with a small amount (such as less than 1%). This high internal phase emulsion using solid particles as a stabilizer is usually called For Pickering high internal phase emulsions. The introduction of solid particles, especially some inorganic nanoparticles, can not only improve the mechanical strength of polymer porous materials, but also endow the materials with special physical properties, such as electrical conductivity, thermal conductivity and magnetic properties. Compared with traditional surfactant-stabilized systems, there are still few studies on the preparation of polymeric porous materials using Pickering high internal phase emulsions as templates. It is precisely because of the stable adsorption of solid particles on the surface of emulsion droplets that using it as a stabilizer can only obtain polymer macroporous materials with closed-pore structure, which greatly limits the application of porous polymers in many fields.

There have been some reports on the preparation of polymer porous materials with a through-pore structure by using Pickering high internal phase emulsions. The main way is to add a small amount of surfactants or substances that interact with stable particles into Pickering high internal phase emulsions. However, the above methods may introduce toxic surfactants or require a specific stabilization system, which has certain limitations. Therefore, the present invention proposes a method for preparing a polymer porous material with a through-hole structure. The hydrophilic inorganic nanoparticles modified by the long-chain modifier are used as the Pickering emulsion stabilizer, and the stabilizer is dispersed in the water phase to prepare the Pickering high internal phase emulsion, and the porous polymer is obtained by template polymerization of the high internal phase emulsion Material.

Contents of the invention

The object of the present invention is to provide a method for preparing a polymer porous material with a through-pore structure. The material prepared by the method has controllable pore structure, large pore diameter and inter-pore channels, and good permeability.

The present invention is realized through the following technical solutions: firstly, the hydrophilic inorganic nanoparticles are uniformly dispersed in water to form a hydrosol, and then a long-chain modifier is added to modify the inorganic nanoparticles; the obtained modified Inorganic nanoparticles are dispersed in water, and monomers and initiators are added to it for homogenization or ultrasonic treatment to form a stable water-in-oil type high internal phase emulsion; after a temperature rise reaction, a polymer porous material with a through-hole structure is obtained .

The preparation method of the porous polymer material provided by the present invention, the specific steps are as follows:

(1) First, evenly disperse the hydrophilic inorganic nanoparticles in water to prepare a 1-20% hydrosol;

(2) Then, adding a long-chain modifier to the hydrophilic inorganic nanoparticle hydrosol to modify the inorganic nanoparticles to obtain modified inorganic nanoparticles;

(3) Then, disperse the above-mentioned modified inorganic nanoparticles in water, the weight of water is 15-200 times (preferably 50-100 times) of the weight of the inorganic nanoparticles; then add the mixed monomer, the weight of the mixed monomer is 3 to 60 times (preferably 10 to 50 times) the weight of inorganic nanoparticles; add an initiator, the weight of the initiator accounts for 2 to 60% (preferably 10 to 50%) of the weight of inorganic nanoparticles; wherein, in the mixed monomer Monomers containing one carbon-carbon double bond and monomers containing two or more carbon-carbon double bonds;

(4) Finally, treat the above mixture with a homogenizer or ultrasonic wave for 5-60 minutes to form a water-in-oil type high internal phase emulsion; transfer the emulsion into a closed container, fill it with nitrogen for protection, and store it at 50-80 °C After the reaction, excess water and unreacted monomers in the product were removed, and vacuum-dried at 40-80 °C for 24-48 h to obtain a polymer porous material with a through-pore structure.

In the present invention, the hydrophilic inorganic nanoparticles are one of silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ) and zinc oxide (ZnO), with a particle size of 1-1000 nm (preferably a particle size of 1 ~500 nm), the corresponding hydrophilic inorganic nanoparticle hydrosol is silica sol, titanium dioxide sol or zinc oxide sol.

In the present invention, the long-chain modifier is one or more of γ-methacryloxypropyl trimethoxysilane, C _8~18 containing trimethoxysilane and triethoxysilane ;

In the present invention, the following conditions can be used to modify the inorganic nanoparticles: the long-chain modifier accounts for 5-80% of the weight of the hydrophilic inorganic nanoparticles, and the temperature is continuously stirred at 40-70 °C for 2-10 h, and then centrifuged Washing and vacuum drying at 40-100 °C to obtain modified inorganic nanoparticles;

In the present invention, the monomer containing a carbon-carbon double bond in the mixed monomer is one or more of styrene, vinyl acetate, methacrylates, acrylates and acrylonitrile; The monomer containing two or more carbon-carbon double bonds in the monomer is one or more of divinylbenzene, diacrylates, and triacrylates; the mixed monomer contains one carbon The ratio of monomers with carbon double bonds to monomers containing two or more carbon-carbon double bonds is 99:1~9:1, preferably 90:1~20:1.

In the present invention, the initiator is one of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanonitrile, lauryl peroxide or dibenzoyl peroxide; The weight is 2-60% (preferably 10-40%) of the weight of the inorganic nanoparticles. the

The polymer porous material prepared by the present invention has a through-pore structure, the pore diameter of the porous material is 20-300 μm, the channel size on the pore wall is 5-100 μm, and the porosity is 75-90%.

The method of the invention has the advantages of simple process, low cost and wide applicability, and the prepared polymer porous material has a through-pore structure, the pore structure can be adjusted freely, the pore diameter and the channel between the pores are large, and the permeability is good. It can be used as separation medium, catalyst support, and cytoskeleton material.

Description of drawings

FIG. 1 is a scanning electron micrograph of the porous polymer material prepared in Example 1.

FIG. 2 is a scanning electron micrograph of the porous polymer material prepared in Example 2.

Detailed ways

The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. Any simple modifications, equivalent changes and modifications made to the following examples according to the technical essence of the present invention still belong to the scope of the technical solutions of the present invention.

In the following examples, the long-chain modifiers used include γ-methacryloxypropyltrimethoxysilane, octyltriethoxysilane, and octadecyltrimethoxysilane.

The raw materials in the following examples are all commercially available products.

Example 1

1. Add γ-methacryloxypropyltrimethoxysilane to a 20% aqueous solution of hydrophilic SiO ₂ nanoparticles with an average _particle size of 40 nm. The weight of γ-methacryloxypropyltrimethoxysilane accounted for 55% of the weight of SiO ₂ , stirred and reacted at 50 °C for 2 h, washed with ethanol after centrifugation, repeated three times, and then dried in a vacuum oven at 60 °C After 24 h, the modified SiO ₂ nanoparticles were obtained.

2. Ultrasonic disperse the above-mentioned modified SiO ₂ nanoparticles in water for 30 min, the quality of water is 100 times the mass of SiO ₂ ; add a styrene monomer containing a carbon-carbon double bond to the aqueous dispersion of SiO ₂ , whose mass is 20 times the mass of _SiO2 ; then add ethylene glycol dimethacrylate containing two carbon-carbon double bonds, whose weight is 20% of the mass of _SiO2 ; finally add the initiator azobisisobutyronitrile , whose weight is 20% of the mass of SiO ₂ .

3. Homogenize the above mixed solution at a speed of 6000 r/min for 15 minutes to form a water-in-oil type high internal phase emulsion. The resulting high internal phase emulsion was transferred to a hydrothermal reactor, filled with nitrogen and sealed. Placed in a blast oven at 65 °C for 12 h.

4. Put the product obtained from the above reaction into a Soxhlet extractor, use methanol as a solvent, extract for 48 h at a temperature of 75 °C, and then dry it in a vacuum oven at 60 °C for 24 h to obtain a polymer with a through-hole structure. porous material. The pore diameter is about 200 μm, and the channel size between the pores is about 50 μm.

Example 2

1. Experimental device and operation are the same as embodiment 1, the hydrophilic _SiO in the example 1 The mass fraction 20% of nano particle aqueous solution is changed into 10%, and γ-methacryloxypropyl trimethoxysilane is changed into For octadecyltrimethoxysilane, the long-chain modifier accounted for 55% of SiO ₂ mass to 18%, the stirring temperature was changed from 50 °C to 70 °C, and the stirring time was changed from 2 h to 3 h.

2. The experimental device and operation are the same as in Example 1, and the quality of water accounts for 100 times of the quality of SiO ₂ and is changed to 170 times; the styrene monomer is changed to a styrene and methyl methacrylate mixed monomer with a weight ratio of 1:1 Body, whose mass accounts for 20 times of SiO ₂ mass instead of 40 times; Ethylene glycol dimethacrylate is changed into divinylbenzene, and its weight is 40% of SiO ₂ mass; Initiator azobisisobutyronitrile is changed For dibenzoyl peroxide, its weight accounts for 30% of the _SiO mass.

3. The experimental device and operation are the same as in Example 1, but the homogenization is changed to ultrasonic treatment, the ultrasonic power is 1000 W, and the time is 5 min; the oven temperature is changed to 73 °C, and the reaction time is changed to 24 h.

4. The experimental device and operation were the same as in Example 1, but the Soxhlet extraction was changed to ultrasonication in ethanol solvent for 10 min. The final porous material had a pore size of about 250 μm and a channel size of about 85 μm.

Example 3

1. The experimental device and operation are the same as in Example 1, but the silicon dioxide (SiO ₂ ) in Example 1 is changed to titanium dioxide (TiO ₂ ), the average particle size is changed from 40 nm to 10 nm, and the γ-methacryloxy Propyltrimethoxysilane was changed to octyltriethoxysilane, and the long-chain modifier accounted for 30% of the mass of _TiO2 .

2. Experimental device and operation are the same as embodiment 1, change 100 times of water quality accounted for nano particle quality into 175 times in embodiment 1; Styrene monomer is changed into methyl methacrylate, and its weight accounts for _TiO times; Ethylene glycol dimethacrylate is changed to a mixture of ethylene glycol dimethacrylate and trimethylolpropane triacrylate in a weight ratio of 1:2, and its weight accounts for 1.5 times the mass of TiO ₂ ; the initiator Azobisisobutyronitrile accounts for 25% of the mass of TiO ₂ .

3. The experimental device and operation are the same as in Example 1, but the homogenization speed is changed from 6000 r/min to 3000 r/min, the homogenization time is changed from 15 min to 10 min, and the oven temperature is changed to 70 °C.

4. The experimental device and operation are the same as in Example 1, and the product is subjected to Soxhlet extraction with acetone, and finally a polymer porous material with a through-pore structure is obtained, the pore diameter is about 290 μm, and the channel size is about 100 μm.

Example 4

1. The experimental device and operation are the same as in Example 1, but the silicon dioxide (SiO ₂ ) in Example 1 is changed to zinc oxide (ZnO), the average particle size is changed from 40 nm to 500 nm, and the mass fraction of the aqueous solution of ZnO nanoparticles is changed to The weight of γ-methacryloxypropyltrimethoxysilane accounted for 55% of SiO ₂ mass was changed to 30%.

2. Experimental device and operation are the same as in Example 1, and the water quality accounts for 100 times of the nanoparticle quality in Example 1 and changes it into 50 times; Styrene monomer is changed into acrylonitrile, and its weight accounts for 15 times of ZnO weight; Ethylene glycol acrylate is changed to divinylbenzene, and its weight is 1.5 times that of ZnO; the initiator azobisisobutyronitrile is changed to azobisisoheptanonitrile.

3. The experimental device and operation are the same as in Example 1, but the homogenization is changed to ultrasonic treatment, the ultrasonic power is 1000 W, and the time is 20 min.

4. The experimental device and operation were the same as in Example 1, but the Soxhlet extraction was changed to ultrasonication in methanol solvent for 5 min, and the finally obtained porous material had a pore diameter of 140 μm and a channel size of about 25 μm.

Example 5

Evaluation of Permeability of Polymer Porous Materials

Select the porous polymer material prepared in Examples 1 and 2, whose shape is all 1 cm long and cylindrical with a diameter of 1.4 cm; measure the nitrogen flow rate at which the sample is placed under a pressure of 500 Pa, and the nitrogen flow rate of the sample in Example 1 is 150 mL/min, sample nitrogen flow rate is 100 mL/min among the embodiment 2.

It can be seen from the gas flow data that the porous polymer material prepared by the present invention has good permeability.

Example 6

Separation Performance Evaluation of Polymer Porous Materials

Select the porous polymer material prepared in Examples 1 and 2, whose shape is all 1 cm long and cylindrical with a diameter of 1.4 cm; the sample is placed in an aqueous solution of 5% 3-aminopropyltriethoxysilane at room temperature After stirring for 2 h, the sample was soaked in 1% hydrochloric acid solution for 1 h; the obtained modified sample was immersed in 40 g of sunset yellow aqueous solution with concentrations of 0.05, 0.10, 0.15, and 0.20 mg/g, respectively. After three days of adsorption, the sunset yellow aqueous solution with low concentration (0.05, 0.10 mg/g) became colorless and transparent; the sunset yellow aqueous solution with high concentration (0.15, 0.20 mg/g) became lighter in color.

It can be seen from the adsorption experiment that the polymer porous material prepared by the present invention can be used as a separation medium.

Claims (7)

1. there is a preparation method for the polymer porous material of through-hole structure, be characterised in that concrete steps are as follows:

(1) first, hydrophilic inorganic nano particle is dispersed in water, is mixed with the water-sol of 1 ~ 20%;

(2) then, long-chain properties-correcting agent is joined in the hydrophilic inorganic nano particle water-sol, modification is carried out to inorganic nanoparticles, obtain the inorganic nanoparticles of modification;

(3) then, be scattered in water by the inorganic nanoparticles of above-mentioned modification, the weight of water is 15-200 times of inorganic nanoparticles weight; Add mix monomer again, the weight of mix monomer is 3 ~ 60 times of inorganic nanoparticles weight; Add initiator again, the weight of initiator accounts for 2 ~ 60% of inorganic nanoparticles weight; Wherein, mix monomer is made up of the monomer containing a carbon-carbon double bond and the monomer containing two or more carbon-carbon double bonds;

(4) last, said mixture is used clarifixator or ultrasonication, the time is 5 ~ 60 min, forms water-in-oil-type High Internal Phase Emulsion; Emulsion is proceeded to encloses container, and inflated with nitrogen is protected, at 50 ~ 80 DEG C, react 12 ~ 48 h; After reaction terminates, remove unnecessary water and unreacted monomer in product, at 40 ~ 80 DEG C, vacuum-drying 24 ~ 48 h, obtains the polymer porous material with through-hole structure.

2. the preparation method with the polymer porous material of through-hole structure according to claim 1, be characterised in that described hydrophilic inorganic nano particle is silicon-dioxide, one in titanium dioxide and zinc oxide, particle diameter is 1 ~ 1000 nm, and its corresponding hydrophilic inorganic nanoparticles water-sol is silicon dioxide gel, TiO 2 sol or zinc oxide colloidal sol.

3. the preparation method with the polymer porous material of through-hole structure according to claim 1 and 2, be characterised in that described long-chain properties-correcting agent be γ-methacryloxypropyl trimethoxy silane, containing C _{8 ~ 18}trimethoxy silane and triethoxyl silane in one or more.

4. the preparation method with the polymer porous material of through-hole structure according to claim 3, be characterised in that and described modification carried out to inorganic nanoparticles, adopt following condition: long-chain properties-correcting agent accounts for 5 ~ 80% of hydrophilic inorganic nanoparticle weight, Keep agitation 2 ~ 10 h at 40 ~ 70 DEG C of temperature, centrifuge washing afterwards, and vacuum-drying at 40 ~ 100 DEG C, obtain the inorganic nanoparticles of modification.

5. the preparation method with the polymer porous material of through-hole structure according to claim 1 or 4, to be characterised in that in described mix monomer containing the monomer of a carbon-carbon double bond to be one or more in vinylbenzene, vinyl acetate, methyl acrylic ester, esters of acrylic acid and vinyl cyanide; Monomer containing two or more carbon-carbon double bonds in described mix monomer is one or more in Vinylstyrene, double methacrylate class, triacrylate class; Monomer containing a carbon-carbon double bond in described mix monomer and the monomer ratio containing two or more carbon-carbon double bonds are 99:1 ~ 9:1.

6. the preparation method with the polymer porous material of through-hole structure according to claim 5, is characterised in that described initiator is the one in Diisopropyl azodicarboxylate, 2,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobis(2,4-dimethylvaleronitrile), dilauroyl peroxide or dibenzoyl peroxide; The weight of initiator is 2 ~ 60% of inorganic nanoparticles weight.

7. the polymer porous material with through-hole structure prepared by the described preparation method of one of claim 1-6, aperture of porous material is 20 ~ 300 μm, and the channel sized on hole wall is 5 ~ 100 μm, porosity 75 ~ 90%.