A high temperature carbonized intumescent gel foam and method of making same
By compounding phytic acid, gelatin and glucose and other components, a high-temperature carbonized expanded gel foam is formed to create a dense carbon layer, which solves the problem of existing gel foam being prone to breakage at high temperatures and achieves effective suppression and extinguishing of coal spontaneous combustion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI UNIV OF SCI & TECH
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-02
AI Technical Summary
Existing gel foams are prone to rupture and collapse at high temperatures, losing their ability to cover high-temperature coal bodies, resulting in a decline in their ability to inhibit spontaneous combustion of coal, making it difficult to meet the demand for long-lasting fire prevention and extinguishing materials for safe production in mines.
The compound design uses phytic acid as the acid source, gelatin as the gas source, and glucose as the carbon source to form an intumescent flame retardant system. Combined with the gel system of sodium alginate, pectin, and L-calcium lactate, a dense carbon layer is formed through a carbonization expansion reaction at high temperature, which blocks the transfer of oxygen and heat.
It forms a dense, expanded char layer at high temperatures, which significantly improves coverage and flame retardancy, greatly reduces CO emissions, inhibits coal spontaneous combustion by 79.59%, and achieves excellent fire extinguishing effect.
Smart Images
Figure CN122124436A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fire prevention and extinguishing technology, specifically to a high-temperature carbonized expanding gel foam and its preparation method. Background Technology
[0002] Coal energy plays an irreplaceable role in driving global economic development. However, as coal mining depth and intensity gradually increase, coal mine disasters are also on the rise. Among them, spontaneous combustion caused by coal oxidation not only burns large amounts of coal resources but also easily triggers major accidents such as gas explosions, causing huge economic losses and casualties. Therefore, taking effective measures to prevent coal spontaneous combustion is beneficial to ensuring safe production in mines.
[0003] Gel foam, as an innovative fire prevention and extinguishing technology, is currently widely used in the prevention and control of spontaneous combustion of coal. This foam can quickly cover a large area, isolating oxygen and heat, thus significantly improving the effect of suppressing spontaneous combustion of coal. However, existing gel foams suffer from problems such as easy rupture and collapse at high temperatures, thereby losing their ability to cover hot coal bodies and ultimately leading to a decline in their performance in suppressing spontaneous combustion of coal at high temperatures, making it difficult to meet the needs of mine safety production for long-lasting fire prevention and extinguishing materials.
[0004] Therefore, there is an urgent need to explore a new type of gel foam material that combines stable coverage with high-temperature crack resistance and flame retardancy to solve the problem of existing products failing to protect against coal under high-temperature conditions. Summary of the Invention
[0005] The purpose of this application is to provide a high-temperature carbonized expanding gel foam and its preparation method. Through the compound design of carbon source, acid source and gas source, it can maintain foam stability and coal body coverage at room temperature. At the same time, under the high temperature conditions of coal spontaneous combustion, it triggers an expansion flame retardant reaction to form a dense carbon layer to block the transfer of oxygen and heat, thereby simultaneously achieving the prevention and suppression of coal spontaneous combustion and overcoming the defects of existing gel foams that are prone to failure at high temperatures.
[0006] To achieve the above objectives, this application adopts the following technical solution:
[0007] In a first aspect, this application provides a high-temperature carbonized expandable gel foam, the components of which include: an expandable flame retardant system, a foaming system, a gel system, and deionized water;
[0008] The intumescent flame retardant system was prepared using phytic acid as the acid source, gelatin as the gas source, and glucose as the carbon source.
[0009] The foaming system is obtained by compounding lauramidopropyl betaine and alkyl glycoside;
[0010] The gel system was prepared from sodium alginate, pectin and L-calcium lactate.
[0011] Furthermore, the intumescent flame retardant system has a mass fraction of 1-10%, the foaming system has a mass fraction of 0.81%, the gel system has a mass fraction of 1.385%, and the remainder is deionized water.
[0012] Furthermore, the mass ratio of phytic acid, gelatin, and glucose in the intumescent flame retardant system is 5:1:1.
[0013] Furthermore, the mass ratio of lauramidopropyl betaine and alkyl glycoside in the foaming system is 1:1;
[0014] Furthermore, the mass ratio of sodium alginate and pectin in the gel system is 3:2, and the mass fraction of L-calcium lactate is 0.075%.
[0015] Secondly, this application provides a method for preparing high-temperature carbonized expanded gel foam, comprising the following steps:
[0016] S1. Take phytic acid, gelatin and glucose according to the ratio, add them to deionized water, stir and dry to obtain an intumescent flame retardant system;
[0017] S2. Dissolve sodium alginate and pectin separately in deionized water according to the ratio to obtain an aqueous solution, and then mix it with L-calcium lactate to obtain a gel system;
[0018] S3. Take lauramidopropyl betaine and alkyl glycoside according to the specified ratio and mix them to obtain a foaming system;
[0019] S4. Add the expanding flame retardant system and the foaming system to the gel system, stir and foam until the foam volume no longer changes, to obtain high-temperature carbonized expanding gel foam.
[0020] Furthermore, in S1, the drying conditions are: vacuum drying at 80℃ for 6 hours.
[0021] Furthermore, in S4, the stirring conditions are: stirring temperature at room temperature, stirring speed at 1800 r / min, and stirring time at 3 min.
[0022] Beneficial effects:
[0023] This application discloses a high-temperature carbonized expandable gel foam and its preparation method. The components include: an expandable flame-retardant system, a foaming system, a gel system, and deionized water. The gel system is prepared from sodium alginate, pectin, and L-calcium lactate. Sodium alginate and pectin molecules contain a large number of carboxyl groups, which can react with the CaO released from L-calcium lactate. 2+A stable "eggshell" structure is formed through ionic cross-linking. Simultaneously, the hydroxyl groups abundant in sodium alginate form hydrogen bonds with the hydroxyl groups of pectin molecules. Through the dual effects of ionic cross-linking and hydrogen bonding, a stable gel network is formed between sodium alginate, pectin, and L-calcium lactate. This structure ensures the uniform compatibility of the components to avoid delamination and significantly improves the density and structural stability of the gel network, enhancing the foam's coverage durability at room temperature.
[0024] In the intumescent flame retardant system, phytic acid, as an acid source, is rich in phosphate groups. At high temperatures, it releases acidic groups, which disrupt the bonding force between hydroxyl groups and hydrogen atoms in the char source molecular chain, causing the char source to lose water molecules and undergo a dehydration and carbonization reaction to form a char skeleton. Gelatin, as a gas source, decomposes at high temperatures to produce gas. The gas diffuses in the pores of the char skeleton, promoting its expansion and ultimately forming a dense intumescent char layer. This char layer can physically block oxygen from contacting the coal body and simultaneously block heat transfer, thus achieving a flame retardant effect.
[0025] When an intumescent flame retardant system and a foaming system are added to a gel system and mixed and foamed, a high-temperature carbonized intumescent gel foam is formed. At room temperature, the foam fills the gaps in the coal body and forms a stable covering layer, achieving initial oxygen isolation and cooling. At high temperature, the gel system melts, and the intumescent flame retardant system simultaneously initiates a carbonization and expansion reaction to form a dense intumescent carbon layer, further enhancing the oxygen isolation and heat insulation effect, thereby achieving the protection effect against spontaneous combustion of coal.
[0026] The prepared high-temperature carbonized expandable gel foam film can form a dense expanded carbon layer of 12 mm from a foam film thickness of 6 mm under high temperature. Compared with raw coal, the CO release of coal samples treated with high-temperature carbonized expandable gel foam at 210℃ was significantly reduced, from 18540 ppm to 3784.91 ppm, with an inhibition rate of 79.59%, indicating that high-temperature carbonized expandable gel foam has a significant inhibitory effect on coal oxidation. Coal combustion tests showed that the temperature of raw coal samples was still as high as 501℃ after 140 min of combustion, while the temperature of coal samples treated with high-temperature carbonized expandable gel foam was only 35℃ after 140 min, indicating that the prepared high-temperature carbonized expandable gel foam has excellent fire extinguishing effect. Attached Figure Description
[0027] Figure 1 This is a flowchart of a method for preparing a high-temperature carbonized expanded gel foam according to this application;
[0028] Figure 2 This is a photograph of the high-temperature carbonized expanded gel foam prepared in Example 1.
[0029] Figure 3 This is a diagram showing the effect of the high-temperature carbonized expanded gel foam film prepared in Example 2 at high temperature.
[0030] Figure 4 The effect of the gel foam film with non-expansion flame retardant system prepared in Comparative Example 1 at high temperature; Detailed Implementation
[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application will be provided below.
[0032] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0033] In the following embodiments, through response surface methodology and optimal component optimization, when the amount of intumescent flame retardant system added is 7.2%, the high-temperature carbonized intumescent gel foam can still have both gel foam characteristics and intumescent performance.
[0034] Example 1
[0035] like Figure 1 As shown, this embodiment provides a method for preparing high-temperature carbonized expanded gel foam, including the following steps:
[0036] S1. Weigh 5.143 g phytic acid, 1.029 g gelatin and 1.029 g glucose, add them to deionized water and stir. Then dry them under vacuum at 80℃ for 6 h to prepare a 20 g intumescent flame retardant system solution.
[0037] S2. Weigh 0.786 g of sodium alginate and 0.524 g of pectin and dissolve them separately in deionized water to obtain aqueous solutions. Then, mix them with 0.075 g of L-calcium lactate and stir to prepare a 70 g gel system solution.
[0038] S3. Weigh 1.16 g lauramidopropyl betaine and 0.81 g alkyl glycoside, mix and stir to obtain 10 g foaming system solution;
[0039] S4. Add the intumescent flame retardant system and the foaming system to the gel system, and stir at 1800 r / min for 3 min at room temperature until the foam volume no longer changes, to obtain high-temperature carbonized intumescent gel foam, as shown. Figure 2 As shown.
[0040] The prepared high-temperature carbonized expanded gel foam had a foaming ratio of 7.62 times, a half-life of 149.6 h, and a gelation time of 13 min. After air drying in a natural environment, 1 g of the gel foam film was weighed and placed at high temperature, and its expansion effect was as follows: Figure 3As shown, the results indicate that under high temperature conditions, high-temperature carbonized expanded gel foam can form a dense expanded carbon layer of 12 mm from a gel foam film thickness of 6 mm.
[0041] Example 2
[0042] A 50 g coal sample, after being treated with 15 g of high-temperature carbonized expanded gel foam, was processed in a vacuum oven at 40°C for 24 h. Figure 3 As shown in the figure, the CO release rate of coal samples during the heating process was recorded through a programmed temperature-increasing oxidation experiment combined with gas chromatography analysis. The results showed that the CO release rate of the coal samples treated with high-temperature carbonization expanded gel foam was low before 140℃, at which temperature the coal samples were in a slow oxidation stage; after 140℃, the CO release rate increased significantly, and the coal samples entered a rapid oxidation stage. Finally, at 210℃, the CO release reached 3784.91 ppm, and the CO inhibition efficiency was 79.59%.
[0043] Example 3
[0044] A coal fire extinguishing experiment was conducted using high-temperature carbonized expanded gel foam, and the temperature change of the coal over time was recorded. The results showed that the coal temperature gradually decreased over time during the extinguishing process. At 90 min, the coal temperature dropped from 958℃ to 100℃, with a temperature drop rate of 9.5℃ / min, and finally dropped to 35℃ at 140 min.
[0045] Comparative Example 1
[0046] This comparative example provides a method for preparing high-temperature carbonized expanded gel foam. The difference from Example 1 is that this comparative example did not prepare or use an expanded flame-retardant system; other process parameters and operating steps are exactly the same as in Example 1. The results show that the gel foam without the expanded flame-retardant system has a foaming ratio of 3.2 times, a half-life of 30 days, and a gel time of 15 minutes. It failed to expand under high temperature, and its effect is as follows: Figure 4 As shown.
[0047] Comparative Example 2
[0048] A 50 g sample of raw coal was weighed and treated in a vacuum oven at 40℃ for 24 h. A programmed temperature-increase oxidation experiment combined with gas chromatography analysis was used to record the CO production during the heating process. The results showed that the CO release rate was slow before 140℃, with a CO release of 1082 ppm at 140℃. After 140℃, the CO release rate increased significantly, eventually reaching 18540 ppm at 210℃.
[0049] Comparative Example 3
[0050] 50 g of coal sample treated with 15 g of non-expansion flame-retardant gel foam was subjected to vacuum drying at 40 °C for 24 h. The CO release during the heating process was recorded using a programmed temperature-increasing oxidation experiment combined with gas chromatography analysis. The results showed that the CO release rate of the coal sample treated with the non-expansion flame-retardant gel foam was low before 140 °C, indicating a slow oxidation phase. After 140 °C, the CO release rate significantly increased, and the coal sample entered a rapid oxidation phase. Finally, at 210 °C, the CO release reached 5589.76 ppm, with a CO inhibition efficiency of 69.85%.
[0051] Comparative Example 4
[0052] Combustion experiments were conducted using raw coal, and the temperature change of the coal sample over time was recorded. After 90 minutes of combustion, the temperature of the raw coal sample dropped to 654℃, with a temperature drop rate of 3.4℃ / min, and finally dropped to 501℃ after 140 minutes.
[0053] Comparative Example 5
[0054] This comparative example provides a method for preparing high-temperature carbonized expanding gel foam. The difference from Example 1 is that in this comparative example, 0.714 g of phytic acid, 0.143 g of gelatin and 0.143 g of glucose are weighed and prepared into an expanding flame retardant system with a mass fraction of 1%. Other process parameters and operating steps are exactly the same as in Example 1.
[0055] Using the same method as in Example 1, the results showed that the high-temperature carbonized expanding gel foam had a foaming ratio of 3.8 times, a half-life of 48.5 h, and a gelation time of 17 min, and failed to expand under the influence of high temperature.
[0056] Comparative Example 6
[0057] This comparative example provides a method for preparing high-temperature carbonized expanding gel foam. The difference from Example 1 is that in this comparative example, 7.143 g of phytic acid, 1.429 g of gelatin and 1.429 g of glucose are weighed and prepared into an expanding flame retardant system with a mass fraction of 10%. Other process parameters and operating steps are exactly the same as in Example 1.
[0058] Using the same method as in Example 1, the results showed that the high-temperature carbonized expanding gel foam had a foaming ratio of 3.6 times, a half-life of 50 h, a gelation time of 5 min, and could expand from a gel foam film thickness of 6 mm to 10 mm under the influence of high temperature.
[0059] As can be seen from Example 1 and Comparative Example 1, the gel foam without expansion flame retardant system failed to expand under high temperature; while the high temperature carbonized expansion gel foam can form a dense expanded carbon layer of 12 mm from a foam film thickness of 6 mm under high temperature, thereby continuously covering the high temperature coal body and overcoming the problems of easy cracking and collapse of traditional gel foam under high temperature.
[0060] As can be seen from Examples 1 and Comparative Examples 5 and 6, the gel foam with 1% intumescent flame retardant system failed to expand, and the gel foam with 10% intumescent flame retardant system expanded, but the gel time was too short (10-20 min is optimal). However, when 7.2% intumescent flame retardant system was added, the prepared high-temperature carbonized intumescent gel foam had a foaming ratio of 7.62 times, a half-life of 149.6 h, and a gel time of 13 min. Under the influence of high temperature, a dense intumescent carbon layer of 12 mm can be formed from a gel foam film thickness of 6 mm, thus possessing both gel foam characteristics and expansion performance.
[0061] As can be seen from Example 2 and Comparative Example 2, compared with raw coal, the CO release of the coal sample treated with high-temperature carbonization expanded gel foam at 210℃ was significantly reduced, from 18540 ppm to 3784.91 ppm, with an inhibition rate of 79.59%, indicating that high-temperature carbonization expanded gel foam has a significant inhibitory effect on coal oxidation.
[0062] As can be seen from Example 3 and Comparative Example 3, the temperature of the raw coal sample was still as high as 501°C after 140 min of combustion, while the temperature of the coal sample treated with high-temperature carbonization expanding gel foam was only 35°C after 140 min, indicating that the prepared high-temperature carbonization expanding gel foam has excellent fire extinguishing effect.
[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.
Claims
1. A high-temperature carbonized expanded gel foam, characterized in that... This includes intumescent flame retardant systems, foaming systems, gel systems, and deionized water; The intumescent flame retardant system was prepared using phytic acid as an acid source, gelatin as a gas source, and glucose as a carbon source. The foaming system is obtained by compounding lauramidopropyl betaine and alkyl glycoside; The gel system was prepared from sodium alginate, pectin and L-calcium lactate.
2. The high-temperature carbonized expanded gel foam according to claim 1, characterized in that, The intumescent flame retardant system has a mass fraction of 1-10%, the foaming system has a mass fraction of 0.81%, the gel system has a mass fraction of 1.385%, and the remainder is deionized water.
3. The high-temperature carbonized expanded gel foam according to claims 1 and 2, characterized in that, The mass ratio of phytic acid, gelatin and glucose in the intumescent flame retardant system is 5:1:
1.
4. The high-temperature carbonized expanded gel foam according to claims 1 and 2, characterized in that, The mass ratio of lauramidopropyl betaine and alkyl glycoside in the foaming system is 1:
1.
5. The high-temperature carbonized expanded gel foam according to claims 1 and 2, characterized in that, The mass ratio of sodium alginate and pectin in the gel system is 3:2, and the mass fraction of L-calcium lactate is 0.075%.
6. The method for preparing a high-temperature carbonized expanded gel foam according to claims 1-5, characterized in that, Includes the following steps: S1. Take phytic acid, gelatin and glucose according to the ratio, add them to deionized water, stir and dry to obtain an intumescent flame retardant system; S2. Dissolve sodium alginate and pectin separately in deionized water according to the ratio to obtain an aqueous solution, and then mix it with L-calcium lactate to obtain a gel system; S3. Take lauramidopropyl betaine and alkyl glycoside according to the specified ratio and mix them to obtain a foaming system; S4. Add the expanding flame retardant system and the foaming system to the gel system, stir and foam until the foam volume no longer changes, to obtain high-temperature carbonized expanding gel foam.
7. The method for preparing a high-temperature carbonized expanded gel foam according to claim 6, characterized in that, In S1, the drying conditions are: vacuum drying at 80°C for 6 hours.
8. The method for preparing a high-temperature carbonized expanded gel foam according to claim 6, characterized in that, In S4, the stirring conditions are: stirring temperature is room temperature, stirring speed is 1800 r / min, and stirring time is 3 min.