A method for preparing asbestos fiber fire-resistant cloth

Abstract

A method for preparing asbestos fire-resistant cloth comprises the following steps: first preparing a 3% ammonium acetate solution; weighing 1g of asbestos, adding 50mL of ammonium acetate solution, stirring at a speed of 300r / min for 2h, obtaining a first mixed solution and vacuum filtering, removing the material attached to the filter paper, then adding 25mL of anhydrous ethanol and 25mL of deionized water, stirring at a speed of 300r / min for 2h, obtaining a second mixed solution and vacuum filtering, drying and crushing the obtained solid, adding deionized water, dripping propylene glycol and polyvinyl pyrrolidone drop by drop, wherein the dripping amount of propylene glycol and polyvinyl pyrrolidone is 1mL, the stirring speed during the dripping process is 300r / min, and the stirring is continued for 24h after the dripping is completed; finally, the obtained product is transferred to a surface dish, flattened and dried. The asbestos fiber fire-resistant cloth prepared by the method has excellent fiber length, hardness and tightness, and good fire resistance.

Description

Technical Field

[0001] The invention relates to a method for preparing asbestos fire-resistant cloth. Background Art

[0002] Refractory materials are mainly used in industries such as steel, cement, glass, and nonferrous metals. With the rapid development of science and technology, these industries have higher requirements for refractory materials. At the same time, in the competition of the industry, they also require the reduction of the cost of refractory materials. Refractory fiber is also a rapidly developing material among refractory materials today. Refractory fiber is an amorphous heat-resistant material. It is easy to use and has a good energy-saving effect. Refractory fiber uses raw cotton as the main raw material and can be made into various refractory fiber products according to different usage requirements.

[0003] However, existing refractory materials are expensive and unstable in nature, and often suffer from fiber breakage or large-scale damage and wear. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing asbestos fiber fire-resistant cloth. The asbestos fiber fire-resistant cloth prepared by the method has excellent fiber length, hardness and compactness, good fire-resistant performance, and the preparation method is simple and easy to operate.

[0005] In order to solve the above technical problems, the present invention provides a method for preparing asbestos fire-resistant cloth, comprising the following steps:

[0006] (1) Prepare a 3% ammonium acetate solution with ammonium acetate solid for later use;

[0007] (2) Weigh 1 g of asbestos and put it into a first round-bottom flask, add 50 mL of ammonium acetate solution, start a magnetic stirrer, and stir at a speed of 300 r / min for 2 h to obtain a first mixed solution;

[0008] (3) After the stirring is completed, the mixed solution is vacuum filtered, and then the material attached to the filter paper is removed and placed in a second round-bottom flask, 25 mL of anhydrous ethanol and 25 mL of deionized water are added, and a magnetic stirrer is started and stirred at a speed of 300 r / min for 2 h to obtain a second mixed solution;

[0009] (4) vacuum filtering the second mixed solution and drying the obtained solid;

[0010] (5) Grind the solid obtained in step (4), put it into a round-bottom flask, add deionized water, start the magnetic stirrer at a speed of 100 r / min, and then dropwise add propylene glycol and polyvinyl pyrrolidone, wherein the amount of propylene glycol and polyvinyl pyrrolidone added is 1 mL, and the dropping process is accompanied by stirring at a stirring speed of 300 r / min. After the dropwise addition is completed, stirring is continued for 24 hours;

[0011] (6) After the stirring in step (5) is completed, the product is transferred to a surface dish, spread flat and air-dried.

[0012] Advantages of the present invention: The preparation method of the asbestos fiber fire-resistant cloth described in the present invention successfully prepares the asbestos fire-resistant cloth with good performance by adding ammonium acetate, film-forming aid and dispersant to asbestos and stirring and washing the asbestos. The addition of ammonium acetate will not destroy the performance of the material under weak acid conditions, and at the same time reduce the concentration of heavy metals therein. The addition of polyvinyl pyrrolidone is conducive to increasing the length of asbestos fibers, improving the color and ductility of the film. The addition of polyvinyl pyrrolidone can also improve the dispersibility of the film-forming aid and arrange the fibers in an orderly manner. Asbestos products are low in price and have good fireproof and flame retardant effects. By physical and chemical means, the asbestos fabric is coated with a polymer functional film. Through copolymerization modification, it has the uses of flame retardancy and mildew resistance. It can not only retain the fireproof and flame retardant functions of asbestos, but also has a wider range of applications and has a good development prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 These are photos of the first set of experimental results in comparative experiment 1.

[0014] Figure 2 These are photos of the second set of experimental results in comparative experiment 1.

[0015] Figure 3 This is a photo of the third group of experimental results in comparative experiment 1.

[0016] Figure 4 These are photos of the first set of experimental results in comparative experiment 2.

[0017] Figure 5 These are photos of the second set of experimental results in comparative experiment 2.

[0018] Figure 6 This is a photo of the third group of experimental results in comparative experiment 2.

[0019] Figure 7 These are photos of the first set of experimental results in comparative experiment 3.

[0020] Figure 8 These are photos of the second set of experimental results in comparative experiment 3.

[0021] Fig. 9 This is a scanning electron microscope photo of asbestos made with 6% ammonium acetate.

[0022] Fig.10 This is a scanning electron microscope photo of asbestos made with 3% ammonium acetate.

[0023] Fig.11 This is the thermogravimetric-differential thermal analysis curve of asbestos made with 3% ammonium acetate.

[0024] Fig.12 This is the thermogravimetric-differential thermal analysis curve of asbestos made with 6% ammonium acetate.

[0025] Fig.13 This is the thermogravimetric-differential thermal analysis curve of asbestos made with 9% ammonium acetate.

[0026] Fig.14 This is the XRD scan spectrum of asbestos made with 3% ammonium acetate.

[0027] Fig.15 This is the XRD scan spectrum of asbestos made with 6% ammonium acetate.

[0028] Fig.16 This is the XRD scan spectrum of asbestos made with 9% ammonium acetate.

[0029] Fig.17 This is a scanning electron microscope photograph of asbestos without the addition of film-forming aids.

[0030] Fig.18 This is a scanning electron microscope photograph of asbestos with 1 mL of film-forming aid added.

[0031] Fig.19 This is a scanning electron microscope photograph of asbestos with 2 mL of film-forming aid added.

[0032] Fig. 20 This is a scanning electron microscope photograph of asbestos to which 1 mL of polyvinyl pyrrolidone was added.

[0033] Fig.21 This is a scanning electron microscope photograph of asbestos without added polyvinyl pyrrolidone. DETAILED DESCRIPTION

[0034] A method for preparing asbestos fire-resistant cloth comprises the following steps:

[0035] (1) Prepare a 3% ammonium acetate solution with ammonium acetate solid for later use;

[0036] (2) Weigh 1 g of asbestos and put it into a first round-bottom flask, add 50 mL of ammonium acetate solution, start a magnetic stirrer, and stir at a speed of 300 r / min for 2 h to obtain a first mixed solution;

[0037] (3) After the stirring is completed, the mixed solution is vacuum filtered, and then the material attached to the filter paper is removed and placed in a second round-bottom flask, 25 mL of anhydrous ethanol and 25 mL of deionized water are added, and a magnetic stirrer is started and stirred at a speed of 300 r / min for 2 h to obtain a second mixed solution;

[0038] (4) vacuum filtering the second mixed solution and drying the obtained solid;

[0039] (5) Grind the solid obtained in step (4), put it into a round-bottom flask, add deionized water (the amount of deionized water added is very little, which is an inaccurate concept), start the magnetic stirrer at a speed of 100 r / min, and then dropwise add propylene glycol and polyvinyl pyrrolidone, wherein the amount of propylene glycol and polyvinyl pyrrolidone added is 1 mL, and the dropping process is accompanied by stirring at a stirring speed of 300 r / min. After the dropwise addition is completed, stirring is continued for 24 h;

[0040] (6) After the stirring in step (5) is completed, the product is transferred to a surface dish, spread flat and air-dried.

[0041] In order to verify the actual effect of the asbestos fiber fire-resistant cloth described in the present invention, comparative tests are now conducted on the following variables:

[0042] Comparative experiment 1: The influence of different concentrations of ammonium acetate:

[0043] Three experimental groups were selected, and the experimental parameters of each group are shown in Table 1:

[0044] Table 1

[0045]

[0046] The first set of experimental results are as follows Figure 1 The second set of experimental results are shown in Figure 2 The third set of experimental results are shown in Figure 3 shown.

[0047] See also Figure 1-Figure 3 By observing the morphology of asbestos fibers, it can be found that the fibers of asbestos cloth made of ammonium acetate are relatively compact. When the concentration of ammonium acetate is 3%, the fibers on the surface of asbestos are relatively slender, shiny, smooth, and not easy to fall off. As the concentration of ammonium acetate increases, the compactness of the fibers decreases and they begin to fall off.

[0048] Comparative experiment 2: Effects of different film-forming agent dosages:

[0049] Three experimental groups were selected, and the experimental parameters of each group are shown in Table 2:

[0050] Table 2

[0051]

[0052] See also Figure 4-Figure 6When no film-forming agent is added, the asbestos fibers are relatively loose and easy to crush. When 1 mL of film-forming agent is added, the asbestos surface is smooth, and the fibers are closely arranged and not easy to loosen. However, when 2 mL of film-forming agent is added, the film-forming property of asbestos decreases and cracking occurs. Studies have found that within a certain range, as the amount of film-forming agent increases, the film-forming property and water resistance of the material will increase accordingly. However, excessive addition of film-forming agent will have a negative effect on the material, because excessive use will prolong the drying time required for the material, resulting in a decrease in its performance. Adding appropriate film-forming agents to asbestos materials will increase the adhesion between fibers, promote the formation of a network structure, and increase the glossiness of the film.

[0053] Comparative experiment 3: Effects of different dosages of polyvinyl pyrrolidone:

[0054] Two experimental groups were taken, and the experimental parameters of each group are shown in Table 3:

[0055] Table 3

[0056]

[0057] See also Figure 7 -See also Figure 7-Figure 8 Polyvinyl pyrrolidone has good complexing and film-forming properties. The product prepared by adding polyvinyl pyrrolidone to the asbestos system is Figure 7 It can be seen that the fiber surface has a good color. When processing the product, it is also found that the elasticity and flexibility of the film are also significantly enhanced. Comparing the products obtained before and after adding polyvinyl pyrrolidone, it is analyzed that after adding polyvinyl pyrrolidone, the dispersion of the film-forming agent in the asbestos system is also improved.

[0058] Results characterization:

[0059] 1. Characterization of asbestos treated with different concentrations of ammonium acetate:

[0060] See also Figure 9-10 Asbestos made of ammonium acetate with a concentration of 3% and 6% was characterized by scanning electron microscopy and other characterization methods. The specific use of the scanning electron microscope is as follows: the asbestos is evenly pressed on the conductive glue and placed on the machine. Each sample is numbered so that the corresponding target can be found in the later shooting. Then the vacuum is released and the main parameters are set. When the vacuum degree reaches 5×10 -4After Pa, turn on the electron gun, first find the target sample at low magnification, then switch to SEM mode, make coarse adjustments, adjust the brightness and contrast, zoom in, select the test micro area, and then fine-tune and focus to make the image clear, and finally "slow scan, image, take pictures", and then save them, and analyze the fiber morphology of the asbestos sample produced through the imaged pictures. From the figure, we can see the morphological structure of the fiber surface. When the concentration of ammonium acetate is 3%, the fibers are more slender, the arrangement is more compact, and the pores of the fiber tubes are smaller. The asbestos treated with 6% ammonium acetate has a rougher surface, a shorter fiber length, and more impurities.

[0061] See also Figure 11-13 The curve represents the relationship between the physical properties of a substance and the temperature. The specific operation process is as follows: first crush the asbestos and transfer it to the crucible with tweezers. The amount transferred is about 1 / 2 of the crucible. Record the mass of the asbestos used, then clamp the crucible in the slot of the instrument and start the temperature test. After the experiment is completed, copy the data and use origin software to draw a graph to analyze its thermal stability. This experiment measures the asbestos prepared by adding 3%, 6%, and 9% ammonium acetate. According to the thermogravimetric curve analysis, the three are roughly at 60 The maximum decomposition rate is reached between 0℃ and 700℃. At the same time, the three have absorption peaks at 250℃, and the peak intensity of asbestos treated with 3% ammonium acetate is the smallest, and the peak intensity of asbestos treated with 9% ammonium acetate is the largest. Analysis shows that it may be the volatilization of incompletely reacted ammonium acetate. From the thermal difference curve, it can be seen that the three have small and gentle absorption peaks at around 700℃ and the intensities of the three peaks are also small, indicating that the thermal effect of the asbestos is small. Comprehensive analysis shows that the asbestos treated with 3% ammonium acetate is relatively stable at temperatures below 700℃ and has good fire resistance.

[0062] See also Figure 14-16 , scanned with an X-ray diffractometer. The specific operation method is to first take a small amount of asbestos sample and fix it in the sample slot, then put it into the measurement room, then enter the sample name, test date, etc., click Start, the sample starts to be tested, wait until the goniometer automatically returns to its original position after the test, then take out the sample, and then proceed to the next set of tests. The saved data is the original data, so the data must be opened in the jade software first, and then exported as txt type data, and the origin software is used for drawing and analysis to observe where the spectrum of asbestos appears. Asbestos is tested by XRD, and characteristic peaks are observed at around 12° and 24°. It can be seen from the spectrum that several samples have diffraction peaks at around 2θ=12° and 2θ=24°, and the diffraction peaks are characteristic peaks of asbestos, indicating that the skeleton structure of asbestos is basically not damaged.

[0063] 2. Characterization of asbestos treated with different volumes of film-forming aids:

[0064] See also Figure 17-Figure 19,The three groups of samples were observed under a scanning electron microscope. The dosage of film-forming agent directly affects the performance of asbestos. With the increase of the dosage of film-forming agent, the hardness and film-forming properties of the material will increase, but the corresponding anti-adhesion properties will decrease accordingly. From the characterization results, it can be seen that when the dosage of film-forming agent is 1ml, the asbestos fibers are long and arranged regularly and tightly. When the dosage of film-forming agent is continued to be increased to 2ml, the asbestos fibers will break and be arranged in a disorderly manner.

[0065] 3. Characterization of asbestos with different additions of polyvinyl pyrrolidone:

[0066] See also Figure 20-21 ,The two groups of samples were observed under a scanning electron microscope. Before the addition of polyvinyl pyrrolidone, the asbestos fibers were arranged in a disorderly manner, indicating that the distribution of the film-forming aid was uneven. After the addition of polyvinyl pyrrolidone, the asbestos fibers were arranged in a relatively orderly manner.

Claims

1. A method for preparing asbestos fire-resistant cloth, characterized in that: The following steps are involved: (1) Prepare a 3% ammonium acetate solution with ammonium acetate solid for later use; (2) Weigh 1 g of asbestos and put it into a first round-bottom flask, add 50 mL of ammonium acetate solution, start a magnetic stirrer, and stir at a speed of 300 r / min for 2 h to obtain a first mixed solution; (3) After the stirring is completed, the mixed solution is vacuum filtered, and then the material attached to the filter paper is removed and placed in a second round-bottom flask, 25 mL of anhydrous ethanol and 25 mL of deionized water are added, and a magnetic stirrer is started and stirred at a speed of 300 r / min for 2 h to obtain a second mixed solution; (4) vacuum filtering the second mixed solution and drying the obtained solid; (5) Grind the solid obtained in step (4), put it into a round-bottom flask, add deionized water, start the magnetic stirrer at a speed of 100 r / min, and then dropwise add propylene glycol and polyvinyl pyrrolidone, wherein the amount of propylene glycol and polyvinyl pyrrolidone added is 1 mL, and the dropping process is accompanied by stirring at a stirring speed of 300 r / min. After the dropwise addition is completed, stirring is continued for 24 hours; (6) After the stirring in step (5) is completed, the product is transferred to a surface dish, spread flat and air-dried.

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