CN102936113B - Preparation method of hybrid nano composite material for building - Google Patents

Abstract

The invention relates to a building material and a method for producing the material. The hybrid nanocomposite material for construction of the present invention comprises the following components by weight ratio: 100 parts of cement, 10-30 parts of water-based resin, 0.01-45 parts of water-based resin curing agent, 25-50 parts of water, 0.5-2 parts Superplasticizer, 0.1-5 parts of nanofibers, 0.1-5 parts of nanofiber dispersants, 0.01-3 parts of thickening stabilizers, 0.02-0.2 parts of foam suppressors. The invention realizes good dispersion and network distribution of nanofibers in the water-based resin system and the subsequent resin/cement hybrid matrix, and forms a dense network-like cemented structure with the hardened resin and cement, thereby improving the dynamic impact resistance and dynamic damping of the hybrid composite material. performance.

Description

Preparation method of hybrid nanocomposite materials for construction

technical field

The invention relates to a building material and a method for producing the material.

Background technique

The shortcomings of cement/concrete, such as low toughness, high brittleness, and low vibration and energy dissipation properties, have always limited its use as a major civil engineering material. People have been trying to add various high-performance macroscopic fiber materials to reduce the structural failure caused by cement materials. improve its mechanical properties. As we all know, cement-based materials are often a multi-scale, porous gel after hardening, and its pore structure includes both macropores larger than 1 μm and capillary pores between 10 ² -10 ³ nm Transition pores of 10-10 ² nm also include gel pores smaller than 10 nm, and most of them are in the nanometer scale. Correspondingly, macro fiber reinforced cement-based materials still have many defects at the micro/nano scale, which need to be further modified with nanofiber materials or resin fillers to improve their mechanical and functional properties.

The size of nanofibers is similar to the physical characteristic size of light wave wavelength, de Broglie wavelength, coherence length or transmission depth of superconducting state, showing many nano effects, such as quantum size effect, small size effect, surface and interface effect and macroscopic quantum tunnel effect etc. When this high-performance nanofiber is added to the cement matrix, the nanofiber can fill the pores of the cement-based material, improve its microporous structure, and improve the mechanical properties and deformation resistance of the cement matrix. For example, the patent number is ZL200810064075.0 And the Chinese patent with the patent number ZL200810064119.X respectively mentions the use of carbon nanotube nanofibers to enhance the mechanical and mechanical properties of cement-based composite materials such as tensile strength, bending strength, and dynamic impact strength. However, the overall performance of fiber-reinforced composites depends on two factors: the dispersion of fibers and the interfacial bonding strength between fibers and the matrix. For nanofiber-reinforced composites, these two factors are usually contradictory, so its Fiber bridging and toughening effects are difficult to fully exert in the matrix. Moreover, for conductive nanofiber composite cement-based materials, external moisture can invade the interior of the material, and the ion concentration of the pore solution inside the composite material increases, and migration occurs under the action of an electric field, resulting in a polarization effect, which greatly affects the electrical test results of the composite material. stability, which is not conducive to the application of its force-electric effect to develop into a smart sensor device.

The thermosetting resin material for structure is a high-strength adhesive polymer material, which is widely used in impermeability, waterproof, impact resistance, reinforcement, reinforcement, etc. of transportation and building structures, such as the Chinese patent No. ZL20041001094.4 It is mentioned that polymer mortar is used to improve the waterproof and thermal insulation properties of polystyrene boards. However, due to the characteristics of high viscosity, lipophilicity, insolubility in water, and inability to cure in a humid environment, ordinary thermosetting resins cannot be directly mixed with hydrophilic materials, and it is difficult to effectively guarantee long-term compatibility and durability, which limits the use of resin materials in the field of civil engineering. Wider range of applications.

Contents of the invention

In order to overcome the above defects, the present invention provides a hybrid composite material for construction, which overcomes the lack of static and dynamic mechanical properties, low compatibility and durability, and unstable electrical properties of existing nanofiber cement-based materials and polymer-modified cement-based materials. question.

In order to achieve the above object, the present invention adopts the following technical scheme: it includes the following components by weight ratio: 100 parts of cement, 10-30 parts of water-based resin, 0.01-45 parts of water-based resin curing agent, 25-50 parts of water, 0.5 - 2 parts of superplasticizer, 0.1-5 parts of nanofiber, 0.1-5 part of nanofiber dispersant, 0.01-3 part of thickening stabilizer, 0.02-0.2 part of foam suppressor.

Water-based resin (and/or supporting water-based curing agent) is a stable resin emulsion prepared by dispersing resin in the form of particles or droplets in water as the continuous phase medium. It can be better mixed with cement-based materials. Bonding and curing in a humid environment improves the compactness, water resistance, impact toughness and other properties of the hardened cement-based material. Combining nanofibers and water-based resins effectively into cement-based materials to form a network bonded structure without macroscopic defects (MDF) will not only improve the waterproof and impermeability of porous cement-based materials, but also effectively eliminate conductive nanofiber reinforcement. The polarization effect existing in the internal porous solution during the electrical test of the corresponding hybrid composite material, and will exert the macromolecular chain segment of the polymer resin material to exhibit the unique toughness and viscoelasticity under the long-term action of external force/deformation, and then make the hybrid Composite materials have good impact resistance and dynamic damping and vibration reduction capabilities.

The composite material of the present invention also includes 100-250 parts by weight of sand. The sand is medium sand with a fineness modulus of 2.3-3.0 and an average particle size of 0.35-0.5mm; or fine sand with a fineness modulus of 1.6-2.2 and an average particle size of 0.25-0.35mm; or extra-fine sand, The fineness modulus is below 1.5, and the average particle size is below 0.25mm.

Preferably, the thickening stabilizer is methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, sodium alginate, gelatin , Gum Arabic or a mixture of several of them; the nanofiber dispersant is alkylphenol polyoxyethylene ether, polyethylene glycol octylphenyl ether, methyl cellulose, gum Arabic, dodecyl Sodium benzene sulfonate, sodium poly(meth)acrylate, sodium deoxycholate or a mixture of several of them; foam inhibitors are polyacrylate, silane polyether, polyoxypropylene glyceryl ether, polydimethyl One of base siloxanes; nanofibers are carbon nanofibers, carbon nanotubes, silicon carbide nanofibers, _TiO2 nanofibers, _SiO2 nanofibers, ceramic nanofibers, silicon nanofibers, nylon 6 nanofibers, polyaniline One or a mixture of nanofibers, polyvinyl alcohol nanofibers, polyimide nanofibers; the water-based resin is water-based epoxy resin, water-based phenolic resin, water-based urea-formaldehyde resin, water-based melamine-formaldehyde resin, water-based One of polyurethane resin and water-soluble polyimide resin; the superplasticizer is carboxylic acid polyether ester block copolymer-based superplasticizer, naphthalene-based sulfonate-formaldehyde condensate-based superplasticizer, sulfonate One or a mixture of several types of melamine-formaldehyde resin-based high-efficiency water reducers.

Another object of the present invention is to provide the preparation method of above-mentioned material, comprises the steps:

(1) Dissolve 0.01-3 parts of thickening stabilizer, 0.1-5 parts of nanofiber dispersant, and 0.02-0.2 parts of antifoaming agent in 25-50 parts of water by weight to prepare a solution with a mass concentration of 0.1% to 10%. ;

(2) Adding 0.1-5 parts by weight of nanofibers to the solution, performing high-speed stirring and ultrasonic treatment, and then centrifuging the suspension to precipitate a stable colloidal dispersion;

(2) Slowly add the colloidal dispersion to 10-30 parts by weight of water-based resin and mechanically stir, then add 0.01-45 parts by weight of water-based resin curing agent, and stir well;

(3) Adding 0.1-25 parts by weight of water and 100 parts by weight of cement to obtain cement mixed slurry;

(4) Put the mixed slurry into the test mold, vacuumize and remove the foam, and vibrate to form;

(5) After the initial setting of the cement, cover and maintain the surface with the mixed diluent of water-based resin/curing agent until the predetermined age, and then the hybrid composite material is obtained.

In the present invention, the nanofibers are made into corresponding water-based dispersion liquid by combining emulsifier dispersion, shear stirring dispersion, ultrasonic treatment dispersion, and thickener stabilization, and then mixed into water-based resin and cement (sand) materials successively to realize The nanofibers are well dispersed and network distributed in the water-based resin system and the subsequent resin/cement hybrid matrix, and form a dense network bonded structure with the hardened resin and cement. Through the bridging effect of the prior resin cured film, the nanofibers form a better bonding ability with the cement-based material, and the interface has a relatively large relative viscous resistance during the deformation of the cement matrix, thereby improving the dynamic impact resistance of the hybrid composite material. Vibration damping performance with dynamic damping. Compared with the standard nanofiber cement-based composite material, the impact strength, elongation at break, damping coefficient, and impermeability coefficient of the hybrid composite material can be higher by 233.7%, 315.1%, 313.9%, and 356.9%, respectively. Its electrical performance test The repeatability has been improved dozens of times.

Detailed ways

Example 1

The steps of hybrid composite materials are as follows: Measure 0.5g carboxymethyl cellulose, 5.0g alkylphenol polyoxyethylene ether (trade name Triton x-100, referred to as Tx100), 0.1g polyacrylate and add 100mL distilled water (DSW), stirring and dissolving to make a mixture. Weigh 2.0g of multi-walled carbon nanotubes (MWNT) with an outer diameter of 25nm and a length of 15μm, slowly add them into the mixture while stirring, perform mechanical stirring for 30 minutes, and ultrasonic treatment for 3 hours (ultrasonic frequency 40kHz, power 60W) , and then subpackaged and centrifuged for 10 minutes to separate out the settled undispersed agglomerates (weighed, and the content of MWNT in the final dispersion was calculated to be 1.8%) to obtain a uniform carbon nanotube aqueous dispersion for later use. Weigh 22.4g of water-based epoxy resin (EP), 33.6g of water-based resin curing agent, stir the mixed resin and curing agent at low speed for 5 minutes, then add 15ml of MWNT aqueous dispersion while stirring, add DSW69.2ml, and continue stirring at low speed until The white viscous mixture of EP resin is dissolved in the MWNT aqueous dispersion to form a uniform mixed solution. Add 3.0g of superplasticizer FDN and 300g of cement into the mixed solution in turn, and continue to stir for 10 minutes until it becomes a uniform mixed slurry. Finally, put it into the mold, remove it after vacuum defoaming for 5 minutes, and vibrate and smooth it. After the initial setting of the cement, the surface of the test piece was covered with a 5-fold dilution of water-based EP and the corresponding curing agent mixture for curing until the predetermined age, and the carbon nanotube/epoxy resin/cement-based hybrid composite material was obtained.

The measured impact strength, elongation at break, damping coefficient, impermeability coefficient, and resistivity test repeatability (under the same applied electric field strength) of the hybrid composite material are higher than those of the standard carbon nanotube cement-based composite material. 153.9%, 315.1%, 167.3%, 356.9%, 12 times.

Example 2

Add 0.5g polyether carboxylate block copolymer superplasticizer MPEG and 300g sand (fineness modulus 1.6-2.2, average particle size 0.25-0.35mm) into the mixed slurry.

The measured impact strength, elongation at break, damping coefficient, impermeability coefficient, and resistivity test repeatability of the hybrid composite material (under the same applied electric field strength) are higher than those of the standard carbon nanotube cement-based composite material. 214.7%, 275.0%, 267.5%, 264.8%, 29 times.

Others are with embodiment 1.

Example 3

The steps of the hybrid composite material are as follows: Measure 1 g of gum arabic, 6 g of polyethylene glycol octylphenyl ether, and 0.2 g of silanone polyether, add them into 150 mL of distilled water, stir and dissolve, and prepare a mixed solution. Weigh 4.5g of carbon nanotubes, slowly add them into the mixture while stirring, carry out mechanical stirring for 30 minutes, ultrasonic treatment for 3 hours (ultrasonic frequency 40kHz, power 100W), and then subpackage and centrifuge for 15 minutes to precipitate the unsedimented Dispersed agglomerates (weighed, and the content of carbon nanotubes in the final dispersion was calculated to be 2.5%) to obtain a uniform aqueous dispersion of carbon nanotubes for later use. Weigh 30g of water-based phenolic resin, 30g of water-based resin curing agent, stir the mixed resin and curing agent at low speed for 5 minutes, then add 15ml of water-based carbon nanotube dispersion while stirring, add 80ml of water, and continue stirring at low speed until the resin is a white viscous mixture Dissolves in aqueous dispersions to form a homogeneous and consistent mixed solution. Take 3.0g of carboxylic acid polyether ester block copolymer superplasticizer (MPEG), 300g of cement, and 300g of sand (fine sand with a fineness modulus of 1.6-2.2 and an average particle size of 0.25-0.35 mm) in sequence Add to the mixed solution and continue to stir for 10 min until it becomes a uniform mixed slurry. Finally put it into the mold, vacuum defoaming for 5 minutes, remove, vibrate and smooth. After the initial setting of the cement, the surface of the test piece is covered with a 5-fold diluted water-based phenolic resin and the corresponding curing agent mixture and cured until the predetermined age, and the hybrid composite material is obtained.

The measured impact strength, elongation at break, damping coefficient, impermeability coefficient, and resistivity test repeatability (under the same applied electric field strength) of the hybrid composite material are higher than those of the standard carbon nanotube cement-based composite material. 233.7%, 74.8%, 313.9%, 175.0%, 23 times.

Example 4

The thickening stabilizer is polyvinyl alcohol and gum arabic mixed in equal proportions, the nanofiber dispersant is methylcellulose, the antifoaming agent is polyoxypropylene glyceryl ether, and the nanofibers are _TiO2 nanofibers and _SiO2 nanofibers in equal proportions Mixing, water-based thermosetting resin and corresponding water-based resin curing agent is water-based urea-formaldehyde resin, superplasticizer is sulfonated melamine-formaldehyde resin-based superplasticizer SMF, and sand is ultra-fine sand (fineness modulus below 1.5, average particle size below 0.25mm).

The impact strength, elongation at break, damping coefficient, and impermeability coefficient of the hybrid composite were measured to be 13.8%, 24.7%, 7.3%, and 19.7% higher than the standard carbon nanotube cement-based composite.

Others are with embodiment 1.

Example 5

The thickening stabilizer is a mixture of carboxymethyl cellulose, sodium alginate and gelatin, the nanofiber dispersant is a mixture of alkylphenol polyoxyethylene ethers and gum arabic, and the foam inhibitor is polydimethylsiloxane. The nanofiber is a mixture of ceramic nanofiber and silicon nanofiber, the water-based thermosetting resin and the corresponding water-based resin curing agent are water-based melamine-formaldehyde resin, and the superplasticizer is carboxylic acid polyether ester block copolymer high-efficiency water reducer MPEG , Naphthalene sulfonate formaldehyde condensate is a mixture of high-efficiency water reducer FDN, the sand is medium sand (fineness modulus 2.3-3.0, average particle size 0.35-0.5mm).

The measured impact strength, elongation at break, damping coefficient, and impermeability coefficient of the hybrid composite are 54.2%, 75.1%, 68.0%, and 26.7% higher than the standard carbon nanotube cement-based composite.

Others are with embodiment 1.

Example 6

The thickening stabilizer is gum arabic, the nanofiber dispersant is a mixture of sodium poly(meth)acrylate and sodium deoxycholate, the antifoaming agent is polydimethylsiloxane, and the nanofibers are nylon 6 nanofibers, poly Aniline nanofibers and polyvinyl alcohol nanofibers are mixed in equal proportions, the water-based thermosetting resin and the corresponding water-based resin curing agent are water-soluble polyimide resins, the superplasticizer is sulfonated melamine-formaldehyde resin-based superplasticizer SMF, and the sand is Extra fine sand (fineness modulus below 1.5, average particle size below 0.25mm).

The measured impact strength, elongation at break, damping coefficient, and impermeability coefficient of the hybrid composite material are 54.6%, 275.6%, 267.7%, and 87.3% higher than the standard carbon nanotube cement-based composite material, respectively.

Others are with embodiment 1.

Claims (5)

1. a preparation method for nanocomposite for building, is characterized in that, comprises the steps:

(1) by weight 0.01-3 part thickening stabilizer, 0.1-5 part nanofiber dispersion agent, 0.02-0.2 part suds suppressor are dissolved in in 25-50 part water, to be mixed with mass concentration be 0.1%～10% solution;

(2) 0.1-5 weight part nanofiber is joined in solution, carry out high-speed stirring, supersound process, and then suspension is carried out to centrifugal treating, separate out stable colloidal dispersion;

(2) colloidal dispersion is slowly joined to mechanical stirring in 10-30 weight part water-based resin, then add 0.01-45 weight part water-based resin curing agent, stir evenly;

(3) add 0.1-25 weight parts water, 100 parts by weight of cement, obtain cement mixing slurry;

(4) mixed slurry is packed in die trial, vacuumize de-bubble, jolt ramming moulding;

(5), after cement initial set, the maintenance of use resin/curing agent mixed diluting liquid surface coverage, to the predetermined length of time, obtains hybrid composite.

2. preparation method according to claim 1, is characterized in that, component by weight ratio: the superplasticizer that adds 0.5-2 weight part in cement mixing slurry.

3. preparation method according to claim 1, is characterized in that, adds the sand of 100-250 weight part in cement mixing slurry.

4. preparation method according to claim 3, it is characterized in that, sand is medium sand, fineness modulus is that 2.3-3.0, median size are 0.35-0.5mm or fine sand, fineness modulus is that 1.6-2.2, median size are 0.25-0.35 mm or special fine sand, fineness modulus below 1.5, median size is below 0.25 mm.

5. preparation method according to claim 2, it is characterized in that, thickening stabilizer is a kind of in methylcellulose gum, carboxymethyl cellulose, Natvosol, hydroxyethylmethyl-cellulose, Vltra tears, polyvinyl alcohol, sodium alginate, gelatin, gum arabic or wherein several mixing; Nanofiber dispersion agent is a kind of in alkylphenol polyoxyethylene class, Triton X-100, methylcellulose gum, gum arabic, Sodium dodecylbenzene sulfonate, poly-(methyl) sodium acrylate, Sodium desoxycholate or wherein several mixing; Suds suppressor is the one in polyacrylic ester, silane ketone polyethers, polypropylene glycerol aether, polydimethylsiloxane; Nanofiber is carbon nanofiber, carbon nanotube, SiC nano fiber, TiO ₂nanofiber, SiO ₂a kind of in nanofiber, ceramic nanofibers, silicon nanofiber, nylon 6/nanometer fiber, polyaniline nano fiber, polyvinyl alcohol nano, polyimide nano-fiber or wherein several mixing; Water-base resin is the one in aqueous epoxy resins, resol resins, water-based urea-formaldehyde resin, water-based melamine-formaldehyde resin, waterborne polyurethane resin, water-soluble poly imide resin; Superplasticizer is a kind of in carboxylic acid polyetherester block copolymer series high-efficiency water-reducing agent, naphthalene sulfonic salt formaldehyde condensation products series high-efficiency water-reducing agent, sulfonated melamine compound resin series high-efficiency water-reducing agent or wherein several mixing.