Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the aramid fiber modified polymer cement waterproof coating and the preparation method thereof, and the coating has better low-temperature flexibility and durability.
An aramid fiber modified polymer cement waterproof coating, which consists of powder and liquid,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 30-48 wt% of cement, 20-35 wt% of heavy calcium carbonate, 15-40 wt% of silica micropowder, 2-10 wt% of modified aramid fiber and 0.1-1 wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 2-5 wt% of penetrating agent, 0.1-0.5 wt% of defoaming agent, 1-5 wt% of film-forming additive, 0.5-1.5 wt% of dispersing agent and 1-5 wt% of water;
the modified aramid fiber is prepared by the following method: soaking aramid fiber in acetone, ultrasonically cleaning for 4h, washing with deionized water, and drying; adding the aramid fiber and concentrated sulfuric acid into concentrated sulfuric acid, modifying for 2 hours at 40-80 ℃, filtering, placing the obtained aramid fiber into absolute ethyl alcohol, performing ultrasonic dispersion for 30 minutes, adding a hydrochloric acid solution to adjust the pH of the system to 3-4 to obtain a fiber suspension, adding an absolute ethyl alcohol solution of a silane coupling agent accounting for 1/2 volumes of the fiber suspension, reacting for 12 hours at 60 ℃, cooling to room temperature, repeatedly washing with absolute ethyl alcohol and deionized water to be neutral, and placing in a freeze dryer for drying to obtain the modified aramid fiber.
Preferably, the weight ratio of the powder material to the liquid material is 1: (0.8-1.8).
Preferably, the nano material modified ethylene-polyvinyl acetate copolymer emulsion is prepared by physically blending nano titanium dioxide and ethylene-polyvinyl acetate copolymer emulsion, wherein the weight ratio of the nano titanium dioxide to the ethylene-polyvinyl acetate copolymer emulsion is 1-5%.
Preferably, the concentration of the absolute ethyl alcohol solution of the silane coupling agent is 5-15 wt%.
Preferably, the aramid fiber is aramid fiber 1414, the concentrated sulfuric acid is a sulfuric acid solution with the weight percent of more than or equal to 80%, and the silane coupling agent is a silane coupling agent KH 550.
Preferably, the water reducing agent is a polycarboxylic acid water reducing agent; the dispersant is dispersant 5010.
Preferably, the penetrating agent is a lithium silicate solution with the weight percent of 20-50%.
Preferably, the defoaming agent is at least one of a vegetable oil defoaming agent, a polyethylene glycol defoaming agent or a silicone defoaming agent.
Preferably, the film forming auxiliary agent is at least one of glycol ester, butyl cellosolve acetate and ethyl 3-ethoxypropionate EEP.
The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: taking cement, heavy calcium carbonate, silica powder, modified aramid fiber and a water reducing agent, stirring and mixing at a stirring speed of 100-200 r/min for 5-15 min to obtain powder;
(2) liquid material mixing: taking the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming additive, a dispersing agent and water, stirring and mixing at the temperature of 50-70 ℃, the stirring speed of 100-200 r/min and the stirring time of 15-30 min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 5-15 min.
The invention has the advantages that:
(1) the polymer cement waterproof coating has excellent durability, compressive strength, elongation and low-temperature toughness, and obviously solves the problems of poor water resistance, hardening of materials, reduction of elongation, cracking and the like of the waterproof coating in a low-temperature environment;
(2) according to the invention, the modified aramid fiber is added, so that not only can the compressive strength and the elongation of the coating be enhanced, but also the low-temperature flexibility and the bonding strength of the coating can be enhanced;
(3) according to the invention, the ethylene-polyvinyl acetate copolymer emulsion is modified by titanium dioxide, based on good dispersibility of titanium dioxide, excellent ultraviolet resistance, antibacterial property, self-cleaning property and aging resistance performance, and after the ethylene-polyvinyl acetate copolymer emulsion is modified, the ultraviolet resistance, the acid and alkali resistance and the like of the polymer emulsion can be improved, so that the coating has excellent durability.
Detailed Description
Example 1
The aramid fiber modified polymer cement waterproof coating comprises powder and liquid, wherein the weight ratio of the powder to the liquid is 1: 0.8,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 30wt% of cement, 20wt% of heavy calcium carbonate, 40wt% of silica micropowder, 9.9wt% of modified aramid fiber and 0.1wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 2wt% of penetrating agent, 0.1wt% of defoaming agent, 1wt% of film-forming assistant, 0.5wt% of dispersing agent and 1wt% of water;
wherein the water reducing agent is a polycarboxylic acid water reducing agent; the dispersing agent is dispersing agent 5010; the penetrating agent is a lithium silicate solution with the weight percent of 50; the defoaming agent is a vegetable oil defoaming agent; the film-forming additive is decaglycol ester;
the nano material modified ethylene-polyvinyl acetate copolymer emulsion is prepared by physically blending nano titanium dioxide and ethylene-polyvinyl acetate copolymer emulsion, wherein the nano titanium dioxide accounts for 5% of the ethylene-polyvinyl acetate copolymer emulsion by weight;
the modified aramid fiber is prepared by the following method: soaking aramid fiber 1414 in acetone, ultrasonically cleaning for 4h, washing with deionized water, and drying; adding the aramid fiber into concentrated sulfuric acid, wherein the mass ratio of the aramid fiber to the concentrated sulfuric acid is 1:10, the concentrated sulfuric acid is a sulfuric acid solution with the weight percent of more than or equal to 80%, modifying for 2 hours at 40 ℃, filtering, placing the obtained aramid fiber into absolute ethyl alcohol, performing ultrasonic dispersion for 30 minutes, adding a hydrochloric acid solution to adjust the pH value of a system to 3 to obtain a fiber suspension, adding an absolute ethyl alcohol solution of a silane coupling agent KH550 with the volume of 15wt% of that of the fiber suspension 1/2, reacting for 12 hours at 60 ℃, cooling to room temperature, repeatedly washing to be neutral by the absolute ethyl alcohol and deionized water, and placing in a freeze dryer for drying to obtain the modified aramid fiber.
2. The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: taking cement, heavy calcium carbonate, silica micropowder, modified aramid fiber and a water reducing agent, stirring and mixing at a stirring speed of 100r/min for 15 min to obtain powder;
(2) liquid material mixing: mixing the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming auxiliary agent, a dispersing agent and water under stirring at 50 ℃ for 30min at a stirring speed of 100r/min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 5 min.
Example 2
The aramid fiber modified polymer cement waterproof coating comprises powder and liquid, wherein the weight ratio of the powder to the liquid is 1:1,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 35wt% of cement, 25 wt% of heavy calcium carbonate, 36wt% of silica micropowder, 3.8wt% of modified aramid fiber and 0.2wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 3wt% of penetrating agent, 0.2wt% of defoaming agent, 2wt% of film-forming additive, 0.8 wt% of dispersing agent and 2wt% of water;
wherein the water reducing agent is a polycarboxylic acid water reducing agent; the dispersing agent is dispersing agent 5010; the penetrating agent is a 40wt% lithium silicate solution; the defoaming agent is a polyethylene glycol defoaming agent; the film-forming auxiliary agent is hexanediol butyl ether acetate;
the nano material modified ethylene-polyvinyl acetate copolymer emulsion is the same as that in the embodiment 1, wherein the nano titanium dioxide accounts for 4 percent of the weight of the ethylene-polyvinyl acetate copolymer emulsion;
the modified aramid fiber is prepared by the following method: soaking aramid fiber 1414 in acetone, ultrasonically cleaning for 4h, washing with deionized water, and drying; adding the aramid fiber into concentrated sulfuric acid, wherein the mass ratio of the aramid fiber to the concentrated sulfuric acid is 1:10, the concentrated sulfuric acid is a sulfuric acid solution with the weight percent of more than or equal to 80%, modifying for 2 hours at 80 ℃, filtering, placing the obtained aramid fiber into absolute ethyl alcohol, performing ultrasonic dispersion for 30 minutes, adding a hydrochloric acid solution to adjust the pH value of a system to 4 to obtain a fiber suspension, adding an absolute ethyl alcohol solution of a silane coupling agent KH550 with the volume of 10wt% of that of the fiber suspension 1/2, reacting for 12 hours at 60 ℃, cooling to room temperature, repeatedly washing to be neutral by the absolute ethyl alcohol and deionized water, and placing in a freeze dryer for drying to obtain the modified aramid fiber.
2. The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: taking cement, heavy calcium carbonate, silica micropowder, modified aramid fiber and a water reducing agent, stirring and mixing at a stirring speed of 120r/min for 12 min to obtain powder;
(2) liquid material mixing: mixing the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming auxiliary agent, a dispersing agent and water under stirring at the temperature of 55 ℃, the stirring speed of 120r/min and the stirring time of 25 min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 8 min.
Example 3
The aramid fiber modified polymer cement waterproof coating comprises powder and liquid, wherein the weight ratio of the powder to the liquid is 1: 1.2,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 40wt% of cement, 30wt% of heavy calcium carbonate, 23.6wt% of silica micropowder, 6wt% of modified aramid fiber and 0.4wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 4wt% of penetrating agent, 0.3wt% of defoaming agent, 3wt% of film-forming additive, 1wt% of dispersing agent and 3wt% of water;
wherein the water reducing agent is a polycarboxylic acid water reducing agent; the dispersing agent is dispersing agent 5010; the penetrating agent is a 20wt% lithium silicate solution; the defoaming agent is an organic silicon defoaming agent; the film-forming auxiliary agent is 3-ethoxy ethyl propionate EEP;
the nano material modified ethylene-polyvinyl acetate copolymer emulsion is the same as that in example 1, wherein the weight ratio of the nano titanium dioxide to the ethylene-polyvinyl acetate copolymer emulsion is 1%;
the modified aramid fiber is prepared by the following method: soaking aramid fiber 1414 in acetone, ultrasonically cleaning for 4h, washing with deionized water, and drying; adding the aramid fiber into concentrated sulfuric acid, wherein the mass ratio of the aramid fiber to the concentrated sulfuric acid is 1:10, the concentrated sulfuric acid is a sulfuric acid solution with the weight percent of more than or equal to 80%, modifying for 2 hours at 60 ℃, filtering, placing the obtained aramid fiber into absolute ethyl alcohol, performing ultrasonic dispersion for 30 minutes, adding a hydrochloric acid solution to adjust the pH value of a system to 4 to obtain a fiber suspension, adding an absolute ethyl alcohol solution of a silane coupling agent KH550 with the volume of 5wt% of that of the fiber suspension 1/2, reacting for 12 hours at 60 ℃, cooling to room temperature, repeatedly washing to be neutral by the absolute ethyl alcohol and deionized water, and placing in a freeze dryer for drying to obtain the modified aramid fiber.
2. The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: taking cement, heavy calcium carbonate, silica micropowder, modified aramid fiber and a water reducing agent, stirring and mixing at a stirring speed of 150r/min for 10 min to obtain powder;
(2) liquid material mixing: mixing the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming auxiliary agent, a dispersing agent and water under stirring at the temperature of 60 ℃, the stirring speed of 150r/min and the stirring time of 20 min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 10 min.
Example 4
The aramid fiber modified polymer cement waterproof coating comprises powder and liquid, wherein the weight ratio of the powder to the liquid is 1: 1.5,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 42wt% of cement, 35wt% of heavy calcium carbonate, 18wt% of silica micropowder, 4.4wt% of modified aramid fiber and 0.6 wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 4.5wt% of penetrating agent, 0.4wt% of defoaming agent, 4wt% of film-forming assistant, 1.2 wt% of dispersing agent and 4wt% of water;
the water reducing agent, the dispersing agent, the penetrating agent, the defoaming agent, the film forming additive, the nano material modified ethylene-polyvinyl acetate copolymer emulsion and the modified aramid fiber are the same as in example 1.
2. The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: taking cement, heavy calcium carbonate, silica micropowder, modified aramid fiber and a water reducing agent, stirring and mixing at a stirring speed of 180r/min for 8min to obtain powder;
(2) liquid material mixing: mixing the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming auxiliary agent, a dispersing agent and water under stirring at 65 ℃ and at a stirring speed of 180r/min for 18min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 12 min.
Example 5
The aramid fiber modified polymer cement waterproof coating comprises powder and liquid, wherein the weight ratio of the powder to the liquid is 1: 1.8,
the powder material comprises the following raw materials in percentage by weight of 100 percent: 48wt% of cement, 34 wt% of heavy calcium carbonate, 15wt% of silica micropowder, 2wt% of modified aramid fiber and 1wt% of water reducing agent;
the liquid material consists of a nano material modified ethylene-polyvinyl acetate copolymer emulsion, an additive and water, wherein the additive and the water account for the weight percentage of the nano material modified ethylene-polyvinyl acetate copolymer emulsion as follows: 5wt% of penetrating agent, 0.5wt% of defoaming agent, 5wt% of film-forming assistant, 1.5wt% of dispersing agent and 5wt% of water;
the water reducing agent, the dispersing agent, the penetrating agent, the defoaming agent, the film forming additive, the nano material modified ethylene-polyvinyl acetate copolymer emulsion and the modified aramid fiber are the same as in example 1.
2. The preparation method of the aramid fiber modified polymer cement waterproof coating comprises the following steps:
(1) powder mixing: mixing cement, heavy calcium carbonate, silica micropowder, modified aramid fiber and a water reducing agent by stirring at the speed of 200r/min for 5 min to obtain powder;
(2) liquid material mixing: mixing the nano material modified ethylene-polyvinyl acetate copolymer emulsion, a penetrating agent, a defoaming agent, a film forming auxiliary agent, a dispersing agent and water under stirring at the temperature of 70 ℃, the stirring speed of 200r/min and the stirring time of 15 min to obtain a liquid material;
(3) and (3) mixing and stirring the liquid material and the powder material for 15 min.
Comparative example
The same procedure as in example 5 was repeated except that the modified aramid fiber was not added.
Performance detection
The cement waterproof coatings provided by examples 1-5 and comparative example were subjected to performance tests, and the tensile strength, elongation at break, low-temperature flexibility, adhesive strength, water impermeability and the like were tested according to GB/T23445-.
TABLE 1 Performance test results