Preparation method of geopolymer composite coating of polyvinyl alcohol fiber

Abstract

The invention discloses a preparation method of a geopolymer composite coating of polyvinyl alcohol fiber, and relates to the technical field of preparation methods of geopolymer composite coatings, and the preparation method comprises the following steps: mixing manganese slag powder with an alkalized water glass solution, and stirring on a magnetic stirrer for one hour; adding polydimethylsiloxane, polyacrylamide and polyvinyl alcohol fibers to obtain a coating raw material; and uniformly brushing the coating on a wood board by using a painting brush, standing in the air with the air temperature of 25 DEG C and the humidity of 50% for about 24 hours, and curing to obtain a sample with the coating of 8-10mm. The preparation method of the geopolymer composite coating of the polyvinyl alcohol fiber is simple and convenient, the manufacturing cost is not high, the geopolymer composite coating has high temperature resistance, and the mechanical property is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of geopolymer composite coating preparation methods, in particular to a method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber. Background Art

[0002] The significant loss of property and life caused by urban fires has attracted considerable attention, and much effort is being expended to design flame-retardant coatings that protect organic matter from combustion while reducing the release of toxic gases and toxic chemicals. Therefore, a major issue in the preparation of flame retardants today is to continue to improve their sustainable and ecological performance. It is increasingly believed that the poor water resistance and weak flame retardant efficiency of silicate coatings limit their widespread application, and the flame retardant mechanism mainly depends on the endothermic loss of hydration water and the solid rigid foam produced by the melt composed of hydrated silica. However, organic polymer-modified inorganic silicate-based hybrid coatings have opened up a new approach for the preparation of ecological and cost-effective flame retardants. Alkali-activated silica powder-based coatings modified with polydimethylsiloxane (PDMS) exhibit excellent water resistance and fire retardant properties, revealing a new type of environmentally friendly organic-inorganic hybrid coating and proposing a new method for high value-added utilization of industrial solid waste.

[0003] It was found that PVA fiber is corrosion-resistant, acid-resistant, alkali-resistant, light-resistant, high-strength, well-dispersed in water, and has good affinity with water glass. Adding PVA fiber can increase the strength of the coating and reduce cracking, and can improve certain mechanical properties of the specimen. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a PVA fiber geopolymer composite coating that is resistant to high temperatures and has strong mechanical properties, which solves the problems mentioned in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: a method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber, comprising the following steps:

[0006] Preferably, before preparing the coating, a 2 mol / L NaOH solution is prepared for standby use;

[0007] Preferably, ionized water or pure water is used, a certain amount of NaOH solution is dropped into the mixture and stirred evenly;

[0008] Preferably, the uniformly stirred solution is placed on a magnetic stirrer at a speed of 60 r / m for standby use, and a Na2SiO3·9H2O solution with a modulus of 3.3 is dripped into the previously alkalized solution and stirred for 2 h;

[0009] Preferably, 25% of the solution weight of fly ash and mineral powder is added and stirred for 0.5h;

[0010] Preferably, 1% PAM and 1.5% PDMS are dripped, and then 25% manganese slag powder is added, and a glass rod is used to stir clockwise until fully blended;

[0011] Preferably, after stirring evenly, 1% of PVA fiber is added and stirred evenly again;

[0012] Preferably, the coating is finally applied to the wood blocks and wood strips with a thickness of about 1 cm, and is left to stand in air at 25° and 50% humidity for about 24 hours to obtain a finished coating product.

[0013] Beneficial Effects

[0014] The present invention provides a method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber. Compared with the prior art, the method has the following beneficial effects: the method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber is simple in preparation, cost-effective, easy to operate, and can effectively improve the mechanical properties and fireproof properties of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The surface and cross-sectional morphology of the PVA fiber geopolymer composite coating obtained under different conditions in the present invention in a high-temperature combustion climate;

[0016] Figure 2 The high temperature resistance performance of the PVA geopolymer composite coating obtained by the method for preparing the PVA fiber geopolymer composite coating of the present invention;

[0017] Figure 3 The graphs are the compressive and flexural strengths of the PVA fiber geopolymer composite coating obtained under different conditions of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1

[0020] Prepare a 100mm×100mm wooden board, dry it in a hot air blast drying oven, and then apply a 10mm 0.5% PVA fiber geopolymer composite coating. After the coating is dry, fix the board upright on the bracket, aim a 1300° flame spray gun at the center of the board and burn for 60 seconds. After cooling, remove the burned and unburned coatings and grind them in a grinding bowl to obtain two coating powders.

[0021] Example 2

[0022] Several wood blocks were prepared and coated with ordinary geopolymer composite coatings, 0.5% PVA fiber geopolymer composite coatings, 1% PVA fiber geopolymer composite coatings and 2% PVA fiber geopolymer composite coatings respectively. After the coatings were dried normally, the coatings were ground to obtain four different coating powders.

[0023] Example 3

[0024] Several national standard wood blocks GB-1935-2009 and wood strips GB1936-2009 were prepared and coated with 10mm ordinary geopolymer composite coating and different percentages of PVA fiber geopolymer composite coating respectively. The experimental groups were divided into original wood and geopolymer composite coating coated with ordinary geopolymer composite coating and geopolymer composite coating coated with three different PVA fibers. There were five comparative experiments in total. After the coating dried normally, mechanical properties tests were carried out on an MTS universal testing machine. Six groups of experiments were conducted on each coating to obtain the experimental data and then the average value was taken.

[0025] Performance Testing

[0026] (I) Surface morphology of geopolymer composite coating

[0027] Figure 1 The surface and morphology screenshots of the 0.5% PVA fiber geopolymer composite coating before and after combustion in Example 1 of the present invention are shown in the figure. It can be seen from the figure that the irregular flakes formed on the surface of the burned coating are obvious in the comparison of the before and after combustion of Figures a and c. Amorphous and irregular flakes appear on the surface of the coating after combustion, and the fractal holes scattered in the surface cracks help the escape of volatiles. The continuous barrier layer blocks the transfer of heat and mass.

[0028] (II) High temperature resistance test of geopolymer composite coating

[0029] Figure 2 The data of the four different coating powders in the TG test in Example 2 of the present invention show that the residual solids of the original wood decrease sharply to 3.11364% as the temperature increases from 0° to 500°, while the residual solids of the ordinary geopolymer composite coating and the PVA fiber geopolymer composite coating are both above 85%, and the residual solids of the 0.5% PVA fiber geopolymer composite coating account for the largest proportion of 90.90577%. According to Figure 1 The surface morphology of the 0.5% PVA fiber geopolymer composite coating was compared and analyzed before and after combustion, and it was inferred that the 0.5% PVA fiber geopolymer composite coating had the best high temperature resistance.

[0030] (III) Mechanical properties test of geopolymer composite coating

[0031] Figure 3 It can be seen from the mechanical properties of the MTS universal testing machine that in Example 3, a total of five test comparisons were taken, and each comparison sample was tested five times and the average value was taken. From the origin plot, it can be seen that the samples coated with 0.5% PVA fiber geopolymer composite coating have the best compression and bending tests in the bending and compression tests.

[0032] The above experimental results show that the composite coating prepared by the present invention can be used at high temperatures, can meet the working range of 200° to 800°, and has strong mechanical properties.

[0033] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0034] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a geopolymer composite coating of polyvinyl alcohol fiber, characterized in that: The following steps are involved: Step 1: Prepare 50ml of 2mol / LNaOH solution on a clean workbench; Step 2: drying the manganese slag, ore powder and fly ash by using a vacuum dryer, then crushing the manganese slag powder by using a solid crusher, and then sieving it with a sieve to finally obtain manganese slag powder, ore powder and fly ash; Step 3: Dry the wood blocks or strips in an electric hot air drying oven at 30° hot air for later use.

2. The method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber according to claim 1, characterized in that: Manganese slag powder and other high temperature resistant materials such as mineral powder and fly ash are used.

3. The method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber according to claim 2, characterized in that: NaOH solution and Na2SiO3·9H2O solution with a modulus of 3.3 were used.

4. The method for preparing a geopolymer composite coating of a polyvinyl alcohol fiber according to claim 3, characterized in that: Made of polyvinyl alcohol fiber.

5. The method for preparing a geopolymer composite coating of polyvinyl alcohol fiber according to claim 4, characterized in that: Two geopolymers, polyacrylamide and polydimethylsiloxane, are used.

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