Waterproof coating and preparation method thereof

Abstract

The invention relates to the field of coatings, and discloses a waterproof coating and a preparation method thereof. The graphene-based biomass fuel comprises the following components in parts by weight: 100-120 parts of biomass, 10-15 parts of graphene, 80-100 parts of biological wax, 4-6 parts of nano silicon dioxide, 2-3 parts of a surfactant, 20-30 parts of a silanization reagent, 4-5 parts of a cross-linking agent, 1-2 parts of an initiator, 1-2 parts of a dispersing agent, 2-4 parts of an emulsifier, 250-300 parts of ethanol, 200-300 parts of a 50% acetone aqueous solution and 30-50 parts of deionized water. According to the invention, the modified graphene is grafted on the biomass, so that the waterproofness, hardness, cohesiveness and strength of the composite coating are improved; according to the present invention, the biomass and the biological wax are adopted as the raw materials, water is adopted as the dispersion medium to form the aqueous emulsion with the biological wax, the prepared waterproof coating is the aqueous coating, does not contain the organic solvent, is harmless to the human body and is environmentally friendly, and the main raw materials such as the biomass and the biological wax have advantages of wide source, renewability and no secondary pollution after degradation.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a waterproof coating and a preparation method thereof. Background Art

[0002] Waterproof coating is a kind of building waterproof material, which is widely used in waterproofing, moisture-proofing and anti-seepage of roofs, basements, toilets and bathrooms, pools, water towers, exterior walls, subways, bridges and pavements, water conservancy projects, etc.

[0003] Common types of waterproof coatings include polyurethane waterproof coatings, modified asphalt waterproof coatings, and polymer cement-based waterproof coatings. Polyurethane waterproof coatings have high strength, high elongation, and good water resistance, but its raw material isocyanate has certain toxicity and irritation, which is harmful to the human body and the environment. Modified asphalt waterproof coatings have good low-temperature flexibility and are easy to construct, but the tensile strength and elongation at break after film formation are low, and secondary pollution is easy to occur. Polymer cement-based waterproof coatings are one of the main waterproof materials for modern home decoration bathroom waterproofing. Its main components are cement, polymer latex powder, fillers, additives, etc. It has the characteristics of breathability, water resistance, good flexibility, and strong weather resistance. However, the large-scale use of cement will lead to an increase in carbon emissions, which is contrary to the low-carbon policy.

[0004] Biomass resources are of great significance in addressing climate change and solving environmental pollution problems. Biomass resources mainly come from organisms such as plants, animals and microorganisms. They are widely available, renewable, non-toxic and harmless, and environmentally friendly. Chinese patent CN114213958A discloses a one-component polyurethane waterproof coating based on biomass oil and a preparation method. The waterproof coating prepared by the coating has high strength, low viscosity, anti-sagging and other properties, which improves the adaptability of the base layer, construction convenience and reliability, but the raw materials contain isocyanate, which is harmful to the human body and the environment. Summary of the invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide a waterproof coating and a preparation method thereof. The prepared waterproof coating has excellent waterproof performance and tensile strength, is non-toxic and harmless, and is environmentally friendly.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A waterproof coating, whose raw materials are measured by weight and composed of: 100-120 parts of biomass, 10-15 parts of graphene, 80-100 parts of biowax, 4-6 parts of nano silicon dioxide, 2-3 parts of surfactant, 20-30 parts of silanization agent, 4-5 parts of cross-linking agent, 1-2 parts of initiator, 1-2 parts of dispersant, 2-4 parts of emulsifier, 250-300 parts of ethanol, 200-300 parts of 50% acetone aqueous solution, and 30-50 parts of deionized water.

[0008] Preferably, the biomass is one of carboxymethyl cellulose, carboxymethyl chitosan and dialdehyde starch.

[0009] Preferably, the biowax is one of sugarcane wax, beeswax and fruit wax.

[0010] Preferably, the surfactant is polydimethyldiallylammonium chloride.

[0011] Preferably, the silanization agent is one of vinyl silane, ethoxy silane and methacryloxy silane.

[0012] Preferably, the cross-linking agent is DCP, and the initiator is potassium persulfate.

[0013] Preferably, the dispersant is one of sodium pyrophosphate, sodium tripolyphosphate and sodium hexametaphosphate.

[0014] Preferably, the emulsifier is WSG-K02Y.

[0015] The preparation method of the waterproof coating comprises the following steps:

[0016] (1) adding graphene to 3 times the mass of deionized water and dispersing it by ultrasonic vibration for 20-30 minutes, then adding surfactant, nano-silica, and silanization agent, heating to 40-50° C. for reaction for 5-6 hours, then filtering, washing with deionized water for 2-3 times, and drying to obtain modified graphene;

[0017] (2) adding biomass, modified graphene, crosslinking agent, initiator and dispersant to ethanol, heating to 60-65° C. for reaction for 3 h, filtering after the reaction, washing with deionized water for 2-3 times, drying, and then dissolving in 50% acetone aqueous solution, placing in water for dialysis to obtain a micellar aqueous dispersion;

[0018] (3) Add biowax to the micellar water dispersion, heat to melt the biowax, mix and stir evenly, then add an emulsifier, place under ultrasound and stir evenly to obtain a waterproof coating.

[0019] Preferably, the heating temperature in step (3) is 5-8° C. higher than the melting point of the bio-wax used.

[0020] Beneficial effects of the present invention:

[0021] The main raw materials of the present invention are biomass and biowax, which are widely available, renewable, environmentally friendly, and have no secondary pollution after degradation. In addition, biowax is a high-quality hydrophobic material, and the higher fatty acids and alcohols in its wax form a certain degree of crystalline area, which has a dense structure and can well isolate water vapor, giving the material excellent waterproof performance. The present invention also adds modified graphene, which is a two-dimensional layered nanomaterial with a large specific surface area, which is closely combined with biomass to improve the waterproofness, hardness, adhesion and strength of the composite coating. The waterproof coating prepared by the present invention is a water-based coating, which uses water as a dispersion medium and does not contain organic solvents. Therefore, it does not contain harmful substances such as benzene, formaldehyde, free TDI and toxic heavy metals, is non-toxic and tasteless, harmless to the human body, and does not pollute the environment. DETAILED DESCRIPTION

[0022] The following is a further description of a waterproof coating and a preparation method thereof of the present invention in conjunction with an embodiment. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention.

[0023] Embodiment 1:

[0024] A waterproof coating, whose raw materials are measured by weight and composed of: 100 parts of carboxymethyl cellulose, 10 parts of graphene, 80 parts of sugarcane wax, 4 parts of nano-silicon dioxide, 2 parts of polydimethyldiallylammonium chloride, 20 parts of vinyl silane, 4 parts of DCP, 1 part of potassium persulfate, 1 part of sodium pyrophosphate, 2 parts of WSG-K02Y, 250 parts of ethanol, 200 parts of 50% acetone aqueous solution, and 30 parts of deionized water.

[0025] The preparation method of the waterproof coating described in this embodiment comprises the following steps, measured by weight:

[0026] (1) adding graphene to 3 times the mass of deionized water and dispersing it by ultrasonic vibration for 20-30 minutes, then adding polydimethyldiallylammonium chloride, nano-silicon dioxide, and vinyl silane, heating to 40-50° C. for reaction for 5-6 hours, then filtering, washing with deionized water twice, and drying to obtain modified graphene;

[0027] (2) adding carboxymethyl cellulose, modified graphene, DCP, potassium persulfate, and sodium pyrophosphate to ethanol, heating to 60-65° C. for reaction for 3 h, filtering after the reaction, washing with deionized water twice, drying, and then dissolving in a 50% acetone aqueous solution, and dialyzing in water to obtain a micellar aqueous dispersion;

[0028] (3) Add sugarcane wax to the micellar aqueous dispersion, heat to 90°C to melt the sugarcane wax, mix and stir evenly, then add WSG-K02Y, place in ultrasound and stir evenly to obtain a waterproof coating.

[0029] Embodiment 2:

[0030] A waterproof coating, whose raw materials are measured by weight and composed of: 110 parts of carboxymethyl chitosan, 12 parts of graphene, 90 parts of beeswax, 5 parts of nano-silicon dioxide, 2 parts of polydimethyldiallylammonium chloride, 25 parts of ethoxysilane, 5 parts of DCP, 2 parts of potassium persulfate, 2 parts of sodium tripolyphosphate, 3 parts of WSG-K02Y, 275 parts of ethanol, 250 parts of 50% acetone aqueous solution, and 40 parts of deionized water.

[0031] The preparation method of the waterproof coating described in this embodiment comprises the following steps, measured by weight:

[0032] (1) adding graphene to 3 times the mass of deionized water and dispersing it by ultrasonic vibration for 20-30 minutes, then adding polydimethyldiallylammonium chloride, nano-silicon dioxide, and ethoxysilane, heating to 40-50° C. for reaction for 5-6 hours, then filtering, washing with deionized water twice, and drying to obtain modified graphene;

[0033] (2) adding carboxymethyl chitosan, modified graphene, DCP, potassium persulfate, and sodium tripolyphosphate to ethanol, heating to 60-65° C. for reaction for 3 h, filtering after the reaction, washing with deionized water twice, drying, and then dissolving in a 50% acetone aqueous solution, and dialyzing in water to obtain a micellar aqueous dispersion;

[0034] (3) Add beeswax to the micellar water dispersion, heat to 75°C to melt the beeswax, mix and stir evenly, then add WSG-K02Y, place in ultrasound and stir evenly to obtain a waterproof coating.

[0035] Embodiment 3:

[0036] A waterproof coating, whose raw materials are measured by weight and composed of: 100-120 parts of dialdehyde starch, 10-15 parts of graphene, 80-100 parts of fruit wax, 4-6 parts of nano silicon dioxide, 2-3 parts of polydimethyldiallylammonium chloride, 20-30 parts of methacryloxysilane, 4-5 parts of DCP, 1-2 parts of potassium persulfate, 1-2 parts of sodium hexametaphosphate, 2-4 parts of WSG-K02Y, 250-300 parts of ethanol, 200-300 parts of 50% acetone aqueous solution, and 30-50 parts of deionized water.

[0037] The preparation method of the waterproof coating described in this embodiment comprises the following steps, measured by weight:

[0038] (1) adding graphene to 3 times the mass of deionized water and dispersing it by ultrasonic vibration for 20-30 minutes, then adding polydimethyldiallylammonium chloride, nano-silicon dioxide, and methacryloxysilane, heating to 40-50° C. for reaction for 5-6 hours, then filtering, washing with deionized water 3 times, and drying to obtain modified graphene;

[0039] (2) adding dialdehyde starch, modified graphene, DCP, potassium persulfate, and sodium hexametaphosphate to ethanol, heating to 60-65° C. for reaction for 3 h, filtering after the reaction, washing with deionized water for 3 times, drying, and then dissolving in a 50% acetone aqueous solution, and dialyzing in water to obtain a micellar aqueous dispersion;

[0040] (3) Add fruit wax to the micellar water dispersion, heat to 65°C to melt the fruit wax, mix and stir evenly, then add WSG-K02Y, place in ultrasound and stir evenly to obtain a waterproof coating.

[0041] Comparative Example 1:

[0042] The difference between this comparative example and Example 1 is that no biowax is added to all the raw materials, and the other raw materials and steps are the same as those in Example 1.

[0043] Comparative Example 2:

[0044] The difference between this comparative example and Example 1 is that graphene is not added to all the raw materials, and the other raw materials and steps are the same as those in Example 1.

[0045] Waterproof coating performance test:

[0046] The waterproof coatings prepared in Examples 1-3 and Comparative Examples 1-2 were coated on a steel plate with a thickness of 125 μm. After being dried at room temperature, their performance was tested. Some reference standards include: GB / T 16777-2008 (tensile strength); GB / T 6739-1996 (hardness); GB / T 1733-1993 (water resistance); GB / T 18883-2002 (VOC, i.e., volatile organic compounds).

[0047] Table 1: Waterproof coating performance test results

[0048] Tensile strength(MPa) Hardness (pencil) Water resistance (h) VOC(g / kg) Example 1 62.5 4H ＞150 ＜0.1 Example 2 68.7 5H ＞150 ＜0.1 Example 3 63.9 4H ＞150 ＜0.1 Comparative Example 1 58.6 3H ＜100 ＜0.1 Comparative Example 2 34.7 2H ＜100 ＜0.1

[0049] As can be seen from the above table, the water resistance of Comparative Example 1 is worse than that of Example 1, because no biowax is added in Comparative Example 1, while Example 1 contains biowax, which is a high-quality hydrophobic material, and the higher fatty acids and alcohols in its wax form a certain degree of crystalline region, with a dense structure, which can well isolate water vapor and give the material excellent waterproof performance. The tensile strength, hardness and water resistance of Comparative Example 2 are all worse than those of Example 1, because no graphene is added in Comparative Example 2, while Example 1 contains modified graphene, and the two-dimensional layered structure of graphene is closely combined with biomass, which improves the waterproofness, hardness, adhesion and strength of the composite coating. The VOC content of Examples 1-3 and Comparative Examples 1-2 is very small, because the present invention uses water as a dispersion medium, does not contain organic solvents, and therefore does not contain harmful substances such as benzene, formaldehyde, free TDI and toxic heavy metals, and is environmentally friendly.

[0050] The above embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work shall all fall within the scope of protection of the present invention.

Claims

1. A waterproof coating, characterized in that: The raw materials include, by weight, 100-120 parts of biomass, 10-15 parts of graphene, 80-100 parts of biowax, 4-6 parts of nano silicon dioxide, 2-3 parts of surfactant, 20-30 parts of silanization agent, 4-5 parts of crosslinking agent, 1-2 parts of initiator, 1-2 parts of dispersant, 2-4 parts of emulsifier, 250-300 parts of ethanol, 200-300 parts of 50% acetone aqueous solution and 30-45 parts of deionized water.

2. A waterproof coating according to claim 1, characterized in that: The biomass is one of carboxymethyl cellulose, carboxymethyl chitosan and dialdehyde starch.

3. A waterproof coating according to claim 1, characterized in that: The biowax is one of sugarcane wax, beeswax and fruit wax.

4. A waterproof coating according to claim 1, characterized in that: The surfactant is polydimethyldiallylammonium chloride.

5. A waterproof coating according to claim 1, characterized in that: The silanization agent is one of vinyl silane, ethoxy silane and methacryloxy silane.

6. A waterproof coating according to claim 1, characterized in that: The cross-linking agent is DCP, and the initiator is potassium persulfate.

7. A waterproof coating according to claim 1, characterized in that: The dispersant is one of sodium pyrophosphate, sodium tripolyphosphate and sodium hexametaphosphate.

8. The waterproof coating according to claim 1, characterized in that: The emulsifier is WSG-K02Y.

9. A method for preparing a waterproof coating according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) adding graphene to 3 times the mass of deionized water and dispersing it by ultrasonic vibration for 20-30 minutes, then adding surfactant, nano-silica, and silanization agent, heating to 40-50° C. for reaction for 5-6 hours, then filtering, washing with deionized water for 2-3 times, and drying to obtain modified graphene; (2) adding biomass, modified graphene, crosslinking agent, initiator and dispersant to ethanol, heating to 60-65° C. for reaction for 3 h, filtering after the reaction, washing with deionized water for 2-3 times, drying, and then dissolving in 50% acetone aqueous solution, placing in water for dialysis to obtain a micellar aqueous dispersion; (3) Add biowax to the micellar water dispersion, heat to melt the biowax, mix and stir evenly, then add an emulsifier, place under ultrasound and stir evenly to obtain a waterproof coating.

10. The method for preparing a waterproof coating according to claim 9, characterized in that: The heating temperature in step (3) is 5-8° C. higher than the melting point of the biowax used.