Disclosure of Invention
In order to improve the fireproof effect and strength of the gypsum mortar, the application provides the high-strength fireproof gypsum mortar and a preparation method thereof, and adopts the following technical scheme:
In a first aspect, the application provides a high-strength refractory gypsum mortar, which comprises the following substances in parts by weight:
60-80 parts of gypsum;
20-30 parts of cement;
10-20 parts of aggregate;
5-10 parts of filler;
3-5 parts of an additive;
The filler comprises vitrified microbeads, polyphenyl particles and redispersible latex powder, and also comprises layered hydrotalcite.
By adopting the technical scheme, the density, the water absorption, the water resistance and the heat conductivity of the gypsum mortar can be effectively improved by adding the polyphenyl particles, so that the fire-resistant effect of the gypsum mortar is improved. The vitrified micro bubble is of a unique hollow structure, and the vitrified micro bubble can be bypassed during heat transfer, so that the heat conductivity coefficient of the gypsum mortar is reduced, the water absorption capacity of the gypsum mortar can be reduced, and the gypsum mortar can obtain better fireproof and waterproof effects. By matching the polyphenyl particles with the vitrified microbeads, the excellent fireproof effect of the gypsum mortar can be effectively endowed, the excellent grading effect can be formed, and the strength of the gypsum mortar is effectively improved.
The redispersible latex powder is preferably used as a filler, and the polymer film can be formed in the mortar to wrap the pore structure by adding the redispersible latex powder, so that the fire resistance effect of the mortar and the combination effect of all components in the mortar can be further reduced.
The layered hydrotalcite is added in the filler, and can absorb the polyphenyl particles, so that the polyphenyl particles can be partially loaded on the surface of the layered hydrotalcite, the layered hydrotalcite has better hydrophilicity, the agglomeration of the polyphenyl particles can be reduced, the dispersion effect of the polyphenyl particles in the mortar can be improved, a particle-lamellar composite structure can be formed, a good heat-insulating fireproof flame-retardant structure can be formed, and the strength and fireproof effect of the gypsum mortar can be improved.
Optionally, the layered hydrotalcite is layered hydrotalcite modified by a modifier, and the modifier comprises nanocellulose.
By adopting the technical scheme, the layered hydrotalcite is preferably modified by adopting the nanocellulose, the surface of the layered hydrotalcite is provided with more active groups, the nanocellulose and the layered hydrotalcite can be combined through hydrogen bonds, a one-dimensional structure and a two-dimensional structure are mutually stacked to form a multi-layer structure, the heat transfer path can be further prolonged, the heat conductivity coefficient of mortar is reduced, the fire resistance effect of the mortar is improved, and the combination effect of the filler and the mortar base material is enhanced. The introduction of the nanocellulose can also increase the fiber structure in the mortar, and can enhance the combination effect of the polyphenyl particles and the layered hydrotalcite, so that the mortar has excellent fireproof effect and strength.
Optionally, the nanocellulose comprises a modified nanocellulose modified with stearoyl chloride.
By adopting the technical scheme, the nano-cellulose is modified by the stearoyl chloride, and grafting is carried out between the stearoyl chloride and the nano-cellulose through esterification reaction, so that an esterified outer layer is formed on the surface of the nano-cellulose. The esterified outer layer can swell and promote self-assembly, so that not only can the combination effect of the nano cellulose and the layered hydrotalcite be improved, but also the combination effect between the nano cellulose and the polyphenyl particles can be improved, the layered hydrotalcite can fully disperse the polyphenyl particles, and the gypsum mortar can obtain a uniform fireproof effect.
Optionally, the modified nanocellulose is prepared by mixing nanocellulose, N-dimethylacetamide and pyridine, adding stearoyl chloride, stirring for reaction to obtain a reaction product, dispersing the reaction product in ethanol, centrifuging, retaining precipitate, washing, and drying to obtain the modified nanocellulose.
Optionally, the nanocellulose further comprises grafted nanocellulose, and cyclodextrin is grafted on the grafted nanocellulose.
By adopting the technical scheme, the cyclodextrin is grafted with the nano cellulose, and the cyclodextrin can be intercalated into the hydrotalcite interlayer structure, so that the connection strength between the nano cellulose and hydrotalcite is improved. Because the nano cellulose comprises grafted nano cellulose and modified nano cellulose, entanglement can occur between fiber structures, so that the nano cellulose can be connected with hydrotalcite in a self-assembly and intercalation mode, the connection strength between the nano cellulose and the hydrotalcite is improved, and the bonding strength between the polyphenyl particles and the hydrotalcite is further improved, namely, the hydrotalcite can fully disperse the polyphenyl particles.
Optionally, waterproof powder is loaded on the polyphenyl particles, and the waterproof powder is silane-based polymer waterproof powder.
Through adopting above-mentioned technical scheme, utilize polyphenyl granule load waterproof powder, polymer waterproof powder can form the chemical bond with cement particle surface condensation, adsorb on cement particle surface, form the hydrophobic layer on cement particle surface, delayed the erosion of liquid water, improved the water-fast effect of mortar to can improve the bonding effect between polyphenyl granule and the cement, thereby improve the intensity of gypsum mortar.
Optionally, the polyphenyl granules are coated with redispersible latex powder.
Through adopting above-mentioned technical scheme, utilize redispersible latex powder to wrap up polyphenyl granule, form redispersible latex shell outside polyphenyl granule, make polyphenyl granule become hydrophilicity, improve the dispersion effect of polyphenyl granule in gypsum mortar, along with the extension of mixing time, waterproof powder can also release gradually, further improve the bonding effect between polyphenyl granule and the cement, effectively improve the intensity of gypsum mortar.
Optionally, the polyphenyl particles are prepared by immersing polyphenyl particles in waterproof powder finishing liquid, stirring, mixing, filtering, drying to obtain loaded polyphenyl particles, and spraying redispersible latex on the surfaces of the loaded polyphenyl particles to obtain modified polyphenyl particles.
Optionally, the additive comprises a water reducing agent and zinc borate, and the water reducing agent comprises a polycarboxylate water reducing agent.
Through adopting above-mentioned technical scheme, preferably adopt polycarboxylate water-reducer to add to mortar, polycarboxylate water-reducer has certain air entraining effect, and the bubble that produces has ball and floating support effect, can effectively improve the dispersion homogeneity of filler in gypsum mortar, makes polyphenyl granule and vitrified micro bubble can play fire-resistant effect in gypsum mortar evenly. The addition of the water reducing agent can reduce the mixing water consumption in the mortar, so that the pores formed by the evaporation of water in the hardened body are reduced, the strength of the gypsum mortar is improved, and the high-strength refractory gypsum mortar is formed. Zinc borate is a reticular substance with viscosity after combustion, and can make the carbon layer produced by combustion more complete and compact so as to achieve better flame-retardant effect. And zinc borate can be matched with hydrotalcite, and zinc borate can assist hydrotalcite to form a stable and thickened carbon layer, so that the fireproof flame-retardant effect of gypsum mortar can be further improved.
In a second aspect, the application provides a preparation method of high-strength refractory gypsum mortar, which adopts the following technical scheme:
a preparation method of high-strength refractory gypsum mortar comprises the following steps:
s1, preparing raw materials, namely respectively taking gypsum, cement, filler, aggregate, additive and water according to parts by weight;
and S2, preparing mortar, namely stirring and mixing the filler, the aggregate and the additive, adding gypsum and cement, stirring uniformly, and then adding water for continuous stirring to prepare the gypsum mortar.
In summary, the application has the following beneficial effects:
1. As the layered hydrotalcite is added in the filler, the layered hydrotalcite can adsorb the polyphenyl particles, so that the polyphenyl particles can be partially loaded on the surface of the layered hydrotalcite, the layered hydrotalcite has better hydrophilicity, the agglomeration of the polyphenyl particles can be reduced, the dispersion effect of the polyphenyl particles in mortar can be improved, a particle-lamellar composite structure can be formed, a good heat-insulating fireproof flame-retardant structure can be formed, and the strength and fireproof effect of the gypsum mortar can be improved.
2. According to the application, the nano-cellulose is modified by the stearoyl chloride, and grafting is carried out between the stearoyl chloride and the nano-cellulose through esterification reaction, so that an esterified outer layer is formed on the surface of the nano-cellulose. The esterified outer layer can swell and promote self-assembly, so that not only can the combination effect of the nano cellulose and the layered hydrotalcite be improved, but also the combination effect between the nano cellulose and the polyphenyl particles can be improved, the layered hydrotalcite can fully disperse the polyphenyl particles, and the gypsum mortar can obtain a uniform fireproof effect.
3. According to the application, the polyphenyl particles are used for loading waterproof powder, the polymer waterproof powder can be condensed with the surfaces of the cement particles to form chemical bonds, the chemical bonds are adsorbed on the surfaces of the cement particles, and a hydrophobic layer is formed on the surfaces of the cement particles, so that the erosion of liquid water is delayed, the water-resistant effect of mortar is improved, and the bonding effect between polyphenyl particles and cement is improved, thereby improving the strength of gypsum mortar.
Detailed Description
The present application will be described in further detail with reference to examples.
KH550, melin, polyvinyl alcohol, melin, isobutyl triethoxysilane, melin, stearoyl chloride, and nanocellulose, respectively, in an amount of 20-50nm.
Preparation example
Preparation of waterproof powder
Preparation example 1
Mixing KH550, polyvinyl alcohol and isobutyl triethoxysilane with equal mass to obtain polymer solution, adding emulsifier with the addition amount of 20% and span-80 and OP-10 with equal mass, stirring and mixing to obtain emulsion, adding superfine calcium carbonate with the mass ratio of 1:1, stirring, and fluidized bed drying to obtain waterproof powder.
Preparation example of polyphenyl granule
Preparation example 2
Mixing waterproof powder and polyphenyl particles according to a mass ratio of 1:2, dispersing in an aqueous solution containing a silane coupling agent KH550 (the content of KH550 is 10%), performing ultrasonic dispersion with a solid-liquid ratio of 1:10, filtering, and drying to obtain polyphenyl particles loaded with the waterproof powder.
Preparation example 3
And (3) spraying the redispersible latex solution (the mass fraction is 5%) on the premise that the polyphenyl particles loaded with the waterproof powder roll over, and drying to obtain the polyphenyl particles coated with the redispersible latex powder.
Layered hydrotalcite preparation example
Preparation example 4
Mixing layered hydrotalcite with water to obtain dispersion liquid with mass fraction of 10%. Mixing nanocellulose with water to obtain suspension with mass fraction of 20%. And (3) dripping the dispersion liquid into the suspension, wherein the mass ratio of the hydrotalcite to the nanocellulose is 1:2, stirring for 2 hours by using ultrasonic waves, filtering and drying to obtain the modified layered hydrotalcite.
Preparation example 5
Mixing layered hydrotalcite with water to obtain dispersion liquid with mass fraction of 10%. Mixing the modified nanocellulose with water to prepare a suspension with the mass fraction of 20%. And (3) dripping the dispersion liquid into the suspension, wherein the mass ratio of the hydrotalcite to the modified nanocellulose is 1:2, stirring for 2 hours by ultrasonic, filtering and drying to obtain the modified layered hydrotalcite.
The modified nanocellulose is prepared by mixing 1g nanocellulose, 20g N, N-dimethylacetamide and 20g pyridine at 50 ℃, adding stearoyl chloride (the molar ratio of stearoyl chloride to nanocellulose is 3:1), stirring and reacting for 4 hours to obtain a reaction product, dispersing the reaction product in ethanol, centrifuging, retaining a precipitate, washing and drying to obtain the modified nanocellulose.
Preparation example 6
Mixing layered hydrotalcite with water to obtain dispersion liquid with mass fraction of 10%. Mixing nanocellulose with water to obtain suspension with mass fraction of 20%. And (3) dripping the dispersion liquid into the suspension, wherein the mass ratio of the hydrotalcite to the nanocellulose is 1:2, stirring for 2 hours by using ultrasonic waves, filtering and drying to obtain the modified layered hydrotalcite.
The nanocellulose comprises modified nanocellulose and grafted nanocellulose with equal mass.
The modified nanocellulose is prepared by mixing 1g nanocellulose, 20g N, N-dimethylacetamide and 20g pyridine at 50 ℃, adding stearoyl chloride (the molar ratio of stearoyl chloride to nanocellulose is 3:1), stirring and reacting for 4 hours to obtain a reaction product, dispersing the reaction product in ethanol, centrifuging, retaining a precipitate, washing and drying to obtain the modified nanocellulose.
The preparation method of the grafted nanocellulose comprises the steps of weighing 7g of nanocellulose in a container, adding 90ml of 1.5mol/L NaOH solution, stirring for 2 hours at 50 ℃, carrying out suction filtration, washing to obtain neutral pH value, and drying to obtain the pretreated cellulose. 2g of pretreated cellulose is weighed into a container, 50mL of deionized water is added for swelling for 1h, then 12mL of epichlorohydrin and 16mL of 30% NaOH solution are added, stirring is carried out for 2.5h at 40 ℃, suction filtration and deionized water washing are carried out to neutrality, 95% ethanol washing is carried out for three times, and filtration and drying are carried out, thus obtaining the epoxy cellulose. Taking 1.152g of beta-cyclodextrin, adding 20mL of 30% NaOH solution, stirring until the beta-cyclodextrin is dissolved, then adding lg of epoxy cellulose, reacting for 2 hours at 50 ℃, filtering, repeatedly washing with distilled water until the solution is neutral, drying, and grinding into powder to obtain grafted cellulose.
Examples
Examples 1 to 3
In one aspect, the application provides a high-strength refractory gypsum mortar, which comprises gypsum, cement, aggregate, filler and an additive, wherein the concrete mass is shown in the following table.
Wherein the filler comprises vitrified microbeads, polyphenyl particles, redispersible emulsion powder and layered hydrotalcite in a mass ratio of 3:1:1:1.
The additive comprises a polycarboxylate water reducer, zinc borate, hydroxypropyl methyl cellulose ether and an antifoaming agent in a mass ratio of 2:0.5:0.5:0.5.
The aggregate comprises quartz sand.
Gypsum, desulfurized gypsum, mountain eastern light far chemical industry Co., ltd, density of 2.32g/cm3, cement, P.O.5 grade, specific surface area of 346m2/kg, vitrified microbeads, expanded vitrified microbeads of Langfang green environment-friendly technology Co., ltd, polyphenyl particles, polyphenyl plates, redispersible latex powder, layered hydrotalcite, jiangsu giant chemical technology Co., ltd, industrial grade, aluminum magnesium hydrotalcite, polycarboxylate 540P polycarboxylate, defoamer, henan Xingxing water treatment material Co., kx-442, wherein the polyphenyl particles are formed by crushing waste polyphenyl plates, the particle size is 2-4 mm, the bulk density is 18kg/m3, the average particle size is 80 mu m.
On the other hand, the application provides a preparation method of high-strength refractory gypsum mortar, which comprises the following steps:
s1, preparing raw materials:
s11, respectively taking gypsum, cement, filler, aggregate, additive and water according to parts by weight, wherein the water-cement ratio is 0.45.
S12, dispersing polyphenyl particles and layered hydrotalcite in tetrahydrofuran solution, mixing the mixture with stirring, wherein the solid-liquid ratio is 2:10, mixing the mixed solution with ethanol according to the volume ratio of 1:4, filtering, and drying to obtain a pretreatment mixture;
and S2, preparing mortar, namely stirring and mixing the filler, the aggregate and the additive, adding gypsum and cement, stirring uniformly, and then adding water for continuous stirring to prepare the gypsum mortar.
Table 1 examples 1-3 composition
Example 4
The difference from example 3 is that the layered hydrotalcite prepared in preparation example 4 was used in equal mass instead of the layered hydrotalcite in example 3 to prepare gypsum mortar.
Example 5
The difference from example 3 is that the layered hydrotalcite prepared in preparation example 5 was used in equal mass instead of the layered hydrotalcite in example 3 to prepare gypsum mortar.
Example 6
The difference from example 3 is that the layered hydrotalcite prepared in preparation example 6 was used in equal mass instead of the layered hydrotalcite in example 3 to prepare gypsum mortar.
Example 7
The difference from example 3 is that the modified polyphenyl granules prepared in preparation example 2 were used in equal mass instead of polyphenyl granules in example 3 to prepare gypsum mortar.
Example 8
The difference from example 3 is that the gypsum mortar was prepared using the equal mass of the polyphenyl granules coated with the redispersible emulsion powder prepared in preparation example 3 instead of the polyphenyl granules in example 3.
Example 9
The difference from example 6 is that the gypsum mortar was prepared using the equal mass of the polyphenyl granules coated with the redispersible emulsion powder prepared in preparation example 3 instead of the polyphenyl granules in example 3.
Comparative example
Comparative example 1
This comparative example differs from example 3 in that no layered hydrotalcite was added in this comparative example.
Comparative example 2
This comparative example differs from example 3 in that no polyphenyl particles were added in this comparative example.
Performance test
(1) And (3) testing fire resistance, namely testing according to GB/T9978.1-2008 general requirements of the 1 st part of a fire resistance test method for building components, and recording the highest temperature rise of the backfire surface of the sample.
(2) Mechanical property detection (JC/T1023-2021) test the mechanical properties of the mortar.
Table 2 performance test
In examples 1-9, no flame continued for 10s or more on the backfire side of the test piece, no crack penetrating into the test furnace was present on the backfire side, the cotton pad was not ignited, the test piece remained intact, and the test was stopped.
The comparison of performance tests in combination with Table 2 can be found:
1. The comparison of examples 1-3 and comparative examples 1-2 shows that the fire resistance and mechanical properties of the gypsum mortar prepared in examples 1-3 are improved, which means that layered hydrotalcite is added in the filler, the layered hydrotalcite can be used for adsorbing polyphenyl particles, so that the polyphenyl particles can be partially loaded on the surface of the layered hydrotalcite, the layered hydrotalcite has better hydrophilicity, the agglomeration of the polyphenyl particles can be reduced, the dispersion effect of the polyphenyl particles in the mortar can be improved, a particle-lamellar composite structure can be formed, a good heat insulation fire resistance structure can be formed, and the strength and fire resistance effects of the gypsum mortar can be improved. The introduction of polyphenyl particles enables the mechanical strength of the gypsum mortar, but can effectively improve the fire resistance and the light weight of the gypsum mortar and improve the application performance of the gypsum mortar.
2. The comparison of the example 4 and the example 3 shows that the fire resistance effect and the mechanical property of the gypsum mortar prepared in the example 4 are improved, which shows that the nanocellulose and the layered hydrotalcite can be combined through hydrogen bonds, and the one-dimensional structure and the two-dimensional structure are mutually stacked to form a multi-layer structure, so that the heat transfer path can be further prolonged, the heat conductivity coefficient of the mortar is reduced, the fire resistance effect of the mortar is improved, and the combination effect of the filler and the mortar base material is enhanced. The introduction of the nanocellulose can also increase the fiber structure in the mortar, and can enhance the combination effect of the polyphenyl particles and the layered hydrotalcite, so that the mortar has excellent fireproof effect and strength.
3. As a result of comparison between example 5 and example 3, it was found that the gypsum mortar prepared in example 5 was improved in fire resistance and mechanical properties, which indicates that the nanocellulose surface was formed into an esterified outer layer by modifying the nanocellulose with stearoyl chloride in the present application. When the layered hydrotalcite is mixed with polystyrene, the esterified outer layer can be swelled and can promote self-assembly, so that the combination effect of the nano cellulose and the layered hydrotalcite can be improved, the combination effect between the nano cellulose and the polystyrene particles can be improved, the layered hydrotalcite can fully disperse the polystyrene particles, and the gypsum mortar can obtain a uniform fireproof effect.
4. The comparison of example 6 and example 3 shows that the fire-resistant effect and mechanical property of the gypsum mortar prepared in example 6 are improved, which means that the coordination of the grafted nano-cellulose and the modified nano-cellulose can generate entanglement between fiber structures, so that the nano-cellulose can be connected with hydrotalcite by self-assembly and intercalation, the connection strength between the nano-cellulose and hydrotalcite is improved, and the bonding strength between polyphenyl particles and hydrotalcite is further improved, namely, the hydrotalcite can fully disperse the polyphenyl particles
5. The comparison of examples 7-9 and example 3 shows that the fire resistance and mechanical properties of the gypsum mortar prepared in examples 7-9 are improved, which means that the redispersible latex powder is used for wrapping polyphenyl particles, a redispersible latex shell is formed outside the polyphenyl particles, the polyphenyl particles become hydrophilic, the dispersing effect of the polyphenyl particles in the gypsum mortar is improved, the waterproof powder can be gradually released along with the prolonged mixing time, and the aminosilane, the alkoxy silane and the PVA in the waterproof powder can form interpenetrating networks with silica gel, aluminum gel and hydrated calcium sulfoaluminate, so that the bonding effect between the polyphenyl particles and cement is further improved, and the strength of the gypsum mortar is effectively improved.
The present embodiment is only for explanation of the present application and is not to be construed as limiting the present application, and modifications to the present embodiment, which may not creatively contribute to the present application as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present application.