Multifunctional gypsum-based mortar and method of making same

Abstract

Disclosed are a multifunctional gypsum-based mortar and a method of making the same, where the gypsum-based mortar includes 30-40 parts by weight of a gypsum; 30-40 parts by weight of a diatomite; 0.5-3.0 parts by weight of nano TiO.sub.2; and 30-40 parts by weight of a fine aggregate. The gypsum-based mortar provided herein can not only has good adsorption to the formaldehyde based on the hydration structure of gypsum-based cementing material and the diatomite structure, but also decompose the formaldehyde adsorbed by the porous structure, ensuring long-term and effective adsorption to formaldehyde.

Claims

1. A gypsum-based mortar, comprising: 30-35 parts by weight of a gypsum; 30-35 parts by weight of a diatomite; 1-2 parts by weight of nano TiO.sub.2; and 30-35 parts by weight of a fine aggregate.

2. The gypsum-based mortar of claim 1, comprising: 31.015 parts by weight of the gypsum; 32 parts by weight of the diatomite; 1.5 parts by weight of the nano TiO.sub.2; and 30 parts by weight of the fine aggregate.

3. The gypsum-based mortar of claim 1, further comprising: 2-8 parts by weight of a negative ion powder having rare earth and tourmaline powders; wherein the negative ion powder is configured to release negative ions with one or more negative charges.

4. The gypsum-based mortar of claim 2, further comprising: 2-8 parts by weight of a negative ion powder having rare earth and tourmaline powders; wherein the negative ion powder is configured to release negative ions with one or more negative charges.

5. The gypsum-based mortar of 1, further comprising one or more admixtures selected from the group consisting of a water reducing agent, a dispersing agent, a gypsum retarder, a water retaining agent and a defoaming agent.

6. The gypsum-based mortar of claim 1, further comprising: 3-7 parts by weight of a negative ion powder having rare earth and tourmaline powders, wherein the negative ion powder is configured to release negative ions with one or more negative charges; 0.10-0.15 part by weight of a polycarboxylate superplasticizer; 0.08-0.12 part by weight of a redispersible emulsion powder; 0.025-0.04 part by weight of a gypsum retarder; 0.05-0.10 part by weight of a water retaining agent; 0.10-0.20 part by weight of a defoaming agent; and 0.1-1.0 part by weight of an inorganic pigment.

7. The gypsum-based mortar of claim 2, comprising: 4.5 parts by weight of a negative ion powder having rare earth and tourmaline powders, wherein the negative ion powder is configured to release negative ions with one or more negative charges; 0.12 part by weight of a polycarboxylate superplasticizer; 0.1 part by weight of a redispersible emulsion powder; 0.035 part by weight of a gypsum retarder; 0.08 part by weight of a water retaining agent; 0.15 part by weight of a defoaming agent; and 0.5 part by weight of an inorganic pigment.

8. The gypsum-based mortar of claim 1, wherein the gypsum is a α- or β-hemihydrate gypsum; and/or the diatomite is a non-calcined or calcined diatomite containing 70% or more by weight of SiO.sub.2; and/or the nano TiO.sub.2 has a diameter of 100 nm or less; and/or the gypsum-based mortar further comprises a negative ion powder having rare earth in amount of 60% or more and tourmaline powders in amount of 20% or more, wherein the negative ion powder is configured to release negative ions with one or more negative charges.

9. The gypsum-based mortar of claim 8, wherein the gypsum is a desulfurized hemihydrate gypsum; and/or the diatomite is the non-calcined diatomite.

10. The gypsum-based mortar of claim 1, wherein the fine aggregate is a natural river sand, a machine-made sand or a tailing sand; and/or a polycarboxylate superplasticizer is a polycarboxylate ether superplasticizer, a polycarboxylate ester superplasticizer or a combination thereof; and/or a redispersible emulsion powder is selected from the group consisting of an ethylene-vinyl acetate copolymer emulsion powder, an ethylene-vinyl chloride-vinyl laurate terpolymer emulsion powder, a vinyl acetate-ethylene-higher fatty acid vinyl ester terpolymer emulsion powder and a combination thereof; and/or a gypsum retarder is selected from the group consisting of tartaric acid, citric acid, sodium gluconate, a bone glue protein gypsum retarder and a combination thereof; and/or a water retaining agent is selected from the group consisting of methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose and a combination thereof; and/or a defoaming agent is a polyether defoaming agent, a higher alcohol fatty acid ester complex, a polyether-modified silicon or a combination thereof; and/or an inorganic pigment is selected from the group consisting of metal oxide, chromate, carbonate, sulfate, sulfide and a combination thereof.

11. A method of preparing the gypsum-based mortar of claim 1, comprising: mixing all components of the gypsum-based mortar uniformly under stirring to produce the gypsum-based mortar.

12. A method of using the gypsum-based mortar of claim 1, comprising: mixing all components of the gypsum-based mortar under stirring to produce the gypsum-based mortar; mixing the gypsum-based mortar with water uniformly under stirring, wherein the water is 60%-80% by weight of the gypsum-based mortar; and applying the resulting mixture onto an interior wall in a non-humid environment for interior decoration.

13. A gypsum-based mortar comprising: 30-40 parts by weight of a gypsum; 30-40 parts by weight of a diatomite; 0.5-3.0 parts by weight of nano TiO.sub.2; 30-40 parts by weight of a fine aggregate; and 2-8 parts by weight of a negative ion powder having rare earth and tourmaline powders; wherein the negative ion powder is configured to release negative ions with one or more negative charges.

14. A gypsum-based mortar comprising: 30-40 parts by weight of a gypsum; 30-40 parts by weight of a diatomite; 0.5-3.0 parts by weight of nano TiO.sub.2; 30-40 parts by weight of a fine aggregate; 2-8 parts by weight of a negative ion powder having rare earth and tourmaline powders, wherein the negative ion powder is configured to release negative ions with one or more negative charges; 0.10-0.15 part by weight of a polycarboxylate superplasticizer; 0.05-0.15 part by weight of a redispersible emulsion powder; 0.025-0.045 part by weight of a gypsum retarder; 0.05-0.10 part by weight of a water retaining agent; 0.10-0.20 part by weight of a defoaming agent; and 0.1-1.0 part by weight of an inorganic pigment.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

(1) The invention will be described below in detail with reference to the embodiments, and these embodiments are not intended to limit the invention. Unless otherwise specified, the methods or conditions mentioned in the following embodiments are known in the art, or are performed as recommended. Unless otherwise specified, the reagents or instruments used below are commercially available.

(2) The desulfurized hemihydrate gypsum is purchased from Shandong Pingyi Jindun Gypsum Products Co., Ltd., which has an initial setting time greater than 6 min, a final setting time less than 30 min, a 2-h bending strength equal to or greater than 5 MPa and a 2-h compressive strength equal to or greater than 10 MPa.

(3) The non-calcined diatomite is purchased from Jilin Yuantong Mineral Co., Ltd., which has a slit-shaped porous structure, and has a specific surface area of 4100 m.sup.2/g and an average pore size of 9.64 nm.

(4) The fine aggregate consists of two kinds of natural sands (purchased from Heibei Weichang) respectively having a size of 40-70 mesh and 70-140 mesh in a ratio of 2:1.

(5) The negative ion powder is purchased from Shijiazhuang Chilin Mineral Co., Ltd., which has a particle size of 1500 mesh and is greyish white.

(6) The nano-TiO.sub.2 catalyst is an anatase titanium dioxide with a hardness of 5.5-6.0, which is purchased from Jingrui New Materials Co., Ltd.

(7) The polycarboxylate superplasticizer is purchased from Suzhou Xingbang Chemical Building Materials Co., Ltd.; the redispersible emulsion powder is purchased from Jinan Yuekai Chemical Co., Ltd.; the gypsum retarder is purchased from Nanjing Stable Trading Co., Ltd.; the water retaining agent is purchased from Shandong Su Noke Chemical Co., Ltd.; the polyether defoaming agent is purchased from Beijing Jinyuan Donghe Chemical Co., Ltd.; and the inorganic pigment is purchased from Tianjin Shengguangming Pigments Co., Ltd.

(8) The polycarboxylate superplasticizer, redispersible emulsion powder, gypsum retarder, water retaining agent, polyether defoaming agent and inorganic pigment are all powdery.

(9) The gypsum-based mortars prepared in the following examples and comparative examples are tested according to GB/T 28627-2012 for setting time, bending strength, compressive strength and tensile adhesive strength, according to JC/T 1047-2008 for the formaldehyde purification performance and durability and according to JC/T 1024-2007 for efflorescence.

Example 1

(10) Provided herein was a gypsum-based mortar, which was prepared by mixing 31.015 parts by weight of a desulfurized hemihydrate gypsum, 32 parts by weight of a non-calcined diatomite, 30 parts by weight of natural sands, 4.5 parts by weight of a negative ion powder, 1.5 parts by weight of nano TiO.sub.2, 0.12 part by weight of a polycarboxylate superplasticizer, 0.1 part by weight of a redispersible emulsion powder, 0.035 part by weight of a gypsum retarder, 0.08 part by weight of a low-viscosity cellulose ether, 0.15 part by weight of a polyether defoaming agent and 0.5 part by weight of an inorganic pigment uniformly.

(11) After mixed with water which was 70% by weight of the gypsum-based mortar, the mechanical properties of the gypsum-based mortar were shown in Table 2.

(12) TABLE-US-00002 TABLE 2 Mechanical properties of the gypsum-based mortar prepared in Example 1 Index Setting time/h Initial setting 2.0 Final setting 2.3 Bending strength/MPa Oven dry 1.8 Compressive strength/MPa Oven dry 3.5 Tensile adhesive strength/MPa Oven dry 0.52 Formaldehyde purification rate % 89.2 Formaldehyde-removing durability % 79.0 Releasing amount of negative ions (icon/cm.sup.3) 13220 Efflorescence Not found

Example 2

(13) Provided herein was a gypsum-based mortar, which was prepared by mixing 33.823 parts by weight of a desulfurized hemihydrate gypsum, 30 parts by weight of a non-calcined diatomite, 30 parts by weight of natural sands, 4.0 parts by weight of a negative ion powder, 1.2 parts by weight of nano TiO.sub.2, 0.11 part by weight of a polycarboxylate superplasticizer, 0.12 part by weight of a redispersible emulsion powder, 0.037 part by weight of a gypsum retarder, 0.09 part by weight of a low-viscosity cellulose ether, 0.15 part by weight of a polyether defoaming agent and 0.5 part by weight of an inorganic pigment uniformly.

(14) After mixed with water which was 67% by weight of the gypsum-based mortar, the mechanical properties of the gypsum-based mortar were shown in Table 3.

(15) TABLE-US-00003 TABLE 3 Mechanical properties of the gypsum-based mortar prepared in Example 2 Index Setting time/h Initial setting 2.2 Final setting 2.8 Bending strength/MPa Oven dry 2.5 Compressive strength/MPa Oven dry 4.5 Tensile adhesive strength/MPa Oven dry 0.63 Formaldehyde purification rate % 80.4 Formaldehyde-removing durability % 76.5 Releasing amount of negative ions (icon/cm.sup.3) 10250 Efflorescence Not found

Comparative Example 1

(16) Provided herein was a gypsum-based mortar, which was prepared by mixing 37.515 parts by weight of a desulfurized hemihydrate gypsum, 6 parts by weight of a non-calcined diatomite, 55 parts by weight of natural sands, 0.5 part by weight of nano TiO.sub.2, 0.12 part by weight of a polycarboxylate superplasticizer, 0.1 part by weight of a redispersible emulsion powder, 0.035 part by weight of a gypsum retarder, 0.08 part by weight of a low-viscosity cellulose ether, 0.15 part by weight of a polyether defoaming agent and 0.5 part by weight of an inorganic pigment uniformly.

(17) After mixed with water which was 45% by weight of the gypsum-based mortar, the mechanical properties of the gypsum-based mortar were shown in Table 4.

(18) TABLE-US-00004 TABLE 4 Mechanical properties of the gypsum-based mortar prepared in Comparative Example 1 Index Setting time/h Initial setting 1.5 Final setting 2.1 Bending strength/MPa Oven dry 5.7 Compressive strength/MPa Oven dry 13.5 Tensile adhesive strength/MPa Oven dry 0.89 Formaldehyde purification rate % 35.4 Formaldehyde-removing durability % 32.1 Releasing amount of negative ions (icon/cm.sup.3) 310 Efflorescence Not found

Comparative Example 2

(19) Provided herein was a gypsum-based mortar, which was prepared by mixing 33.515 parts by weight of a desulfurized hemihydrate gypsum, 32 parts by weight of a non-calcined diatomite, 32 parts by weight of natural sands, 1.5 parts by weight of nano TiO.sub.2, 0.12 part by weight of a polycarboxylate superplasticizer, 0.1 part by weight of a redispersible emulsion powder, 0.035 part by weight of a gypsum retarder, 0.08 part by weight of a low-viscosity cellulose ether, 0.15 part by weight of a polyether defoaming agent and 0.5 part by weight of an inorganic pigment uniformly.

(20) After mixed with water which was 74% by weight of the gypsum-based mortar, the mechanical properties of the gypsum-based mortar were shown in Table 5.

(21) TABLE-US-00005 TABLE 5 Mechanical properties of the gypsum-based mortar prepared in Comparative Example 2 Index Setting time/h Initial setting 1.8 Final setting 2.2 Bending strength/MPa Oven dry 1.7 Compressive strength/MPa Oven dry 3.5 Tensile adhesive strength/MPa Oven dry 0.50 Formaldehyde purification rate % 73.5 Formaldehyde-removing durability % 69.6 Releasing amount of negative ions (icon/cm.sup.3) 450 Efflorescence Not found

Comparative Example 3

(22) Provided herein was a gypsum-based mortar, which was prepared by mixing 31.515 parts by weight of a desulfurized hemihydrate gypsum, 32 parts by weight of a non-calcined diatomite, 31 parts by weight of natural sands, 4.0 parts by weight of a negative ion powder, 0.12 part by weight of a polycarboxylate superplasticizer, 0.1 part by weight of a redispersible emulsion powder, 0.035 part by weight of a gypsum retarder, 0.08 part by weight of a low-viscosity cellulose ether, 0.15 part by weight of a polyether defoaming agent and 0.5 part by weight of an inorganic pigment uniformly.

(23) After mixed with water which was 74% by weight of the gypsum-based mortar, the mechanical properties of the gypsum-based mortar were shown in Table 6.

(24) TABLE-US-00006 TABLE 6 Mechanical properties of the gypsum-based mortar prepared in Comparative Example 3 Index Setting time/h Initial setting 1.9 Final setting 2.5 Bending strength/MPa Oven dry 1.9 Compressive strength/MPa Oven dry 3.8 Tensile adhesive strength/MPa Oven dry 0.56 Formaldehyde purification rate % 77.8 Formaldehyde-removing durability % 43.5 Releasing amount of negative ions (icon/cm.sup.3) 9837 Efflorescence Not found

(25) Described above are merely preferred embodiments of the invention, and it should be understood that various modifications and changes made by those skilled in the art without departing from the spirit of the invention should fall within the scope of the invention.