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Phosphorous-Based FRs
Published in Asim Kumar Roy Choudhury, Flame Retardants for Textile Materials, 2020
Ammonium Polyphosphate (APP) is considered a high-performance inorganic flame retardant with white powder, decomposition temperature greater than 256°C, degree of polymerization between 10 and 20, and water solubility. APP is poorly soluble in water when the degree of polymerization is larger than 20. Itis cheaper than organic flame retardants, and has low toxicity and good thermal stability. It can be used individually with other flame retardant compounds for flame retardancy. The use of APP is wide; among its most important uses areas a source of acid, and in connection with carbon sources and gas sources consisting of IFRs. Also, it can be used for other fire-retardant plastics, fibers, rubber, paper, wood, and firefighting in large areas of forests and coalfields. Use of APP alone as a flame retardant has been found effective in polyamides and similar polymers.
Flame Retarded Polymer Foams for Construction Insulating Materials
Published in Yuan Hu, Xin Wang, Flame Retardant Polymeric Materials, 2019
Zhengzhou Wang, Xiaoyan Li, Lei Liu
Ammonium polyphosphate (APP), as an addition-type flame retardant, has wide applications in many polymer materials because it is halogen-free and has a low toxicity and a low cost (Shao et al. 2014). APP usually functions in the condensed phase through catalyzing the char formation (Chen et al. 2015; Zheng et al. 2015). Properties of RPU foams with different types and concentrations of fillers such as APP, borax, aluminum hydroxide (ATH), and MC were compared (Barikani et al. 2010). The results indicated that the density of the filled foams increased with increasing the amount of fillers for most of the used flame retardants. The LOI values of the filled RPU foams with APP were the highest among the used flame retardants at the same loading. The presence of the fillers in the foams resulted in a significant improvement in compressive strength of the filled foams, except for borax. Xu et al. (2015c) investigated the effect of APP, DMMP, or their combination with three nanostructured additives, e.g., zinc oxide (ZnO), zeolite, and montmorillonite (MMT) on flame retardant properties of RPU foams. Their results indicated that FR RPU foams with the nano-additives showed different combustion performances. ZnO and MMT narrowed the heat release peak of the FR RPU foams, but the intensity of the peak did not reduce. The peak HRR of the RPU foam with Zeolite/DMMP/APP was only 91 kW/m2, which was 56% lower than that of pure RPU foam, and 26% lower than RPU foam only with DMMP/APP. The LOI value of the RPU/8%APP/8%DMMP foam was 29%, and the incorporation of the nano-additives into the above RPU/DMMP/APP foam did lead to the improvement in LOI.
Study of the Effect of Drive Gas Type on the Inhibition of Coal Spontaneous Combustion by Ternary System Foam
Published in Combustion Science and Technology, 2023
Nan Chen, Hailin Jia, Xiangyu Shao, Rongkun Pan, Ligang Zheng, Chang Lu, Long Cheng
In summary, foam extinguishing agents for coal fires need to have good foaming and foam stabilization capabilities. It is also capable of acting as a synergist of the three materials. In conclusion, both LS-99/isobutyl alcohol concentrations of 0.1% were chosen for subsequent experiments. The binary system foam formulations are shown in Table 2. The components in Table 2 were fixed in the ternary system study. Foam formulations contain auxiliary substances to enable the foam extinguishing agent to perform better. The proportion of auxiliary substances is based on conventional foam ratios. Urea and diethylene glycol butyl ether (DGBE) act as co-solvents. The flame retardant is ammonium polyphosphate (APP). The anti-freeze agent is ethylene glycol (EG).
Preparation and properties of ammonium polyphosphate microcapsules for coal spontaneous combustion prevention
Published in International Journal of Coal Preparation and Utilization, 2022
Yan-Ni Zhang, Pan Shu, Jun Deng, Shao-Kang Chen, Xin-Nan Li
Although microencapsulated APP has been widely applied in many fields, such as coating flame retardants, plastic flame retardants, and ultrafine desiccants (Ding et al. 2020; Ran et al. 2019; Zhu and Wang 2020), the research on domestic mine fire prevention and control remains at the initial stage. The application of microcapsule technology in the APP coating process and mine fire prevention can therefore change the shape of coal mine fire prevention materials, overcome the APP deficiencie and let the APP core material flow out at a certain temperature to play a flame retardant effect. The use of microcapsules to coat ammonium polyphosphate ensures the excellent flame-retardant properties of ammonium polyphosphate, thereby effectively preventing the occurrence of spontaneous combustion of coal. In this study, the APP surface is coated through in-situ polymerization. The surface morphology, coating condition, and thermal stability of microcapsules are analyzed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetry (TG). The fire-fighting performance of microcapsules against coal spontaneous combustion is investigated by thermogravimetric analysis. This study provides new insights into the prevention and control of coal spontaneous combustion.
Study on the preparation and application of phenolic resin-based filling composite materials in coal mines
Published in Mining Technology, 2021
Yunfeng Zhang, Jinhua Wu, Xinyu Zhang, Jipeng Zhu
The trend line of the ammonium polyphosphate additive composite material shows a considerable increase but large fluctuation, and when the additive content exceeds 8%, the oxygen index stagnates near 35.5%, followed by fatigue. This is because ammonium polyphosphate is decomposed by heat to generate ammonia gas and phosphoric acid, which can dehydrate and carbonize the surface of the material to dilute and cover, with a good flame-retardant effect (Ge et al. 2020). Aluminium hydroxide has always maintained a strong momentum in terms of both the overall growth effect and the overall growth trend. After adding additives, the oxygen index of the composite material increased by nearly half of the original 25% of the phenolic resin, and a better flame retardant effect of the composite material was obtained. This is because aluminium hydroxide decomposes at high temperatures to generate water vapour, which is an endothermic reaction. In addition, after aluminium hydroxide dehydration, an aluminium oxide protective film forms on the surface of the material, which can isolate oxygen and prevent continued combustion (Wu and Wang 2018). The aluminium hydroxide trend line roughly conforms to a logarithmic form, and the change law is also easier to predict and grasp.