The flame retardant mechanism of APP can be divided into condensed phase flame retardant mechanism and gas-phase flame retardant mechanism. Condensed phase flame retardant mechanism: APP decomposes into phosphoric acid derivatives such as polyphosphate and pyrophosphate when heated. These phosphoric acid derivatives catalyze the cross-linking of polymers into carbon, causing dehydration and carbonization of the substrate surface, forming a non combustible carbon layer. The non combustible carbon layer covers the substrate surface as a physical barrier, delaying the exchange of flammable substances and the conduction of thermal energy, and reducing the decomposition rate of the internal substrate.
Gas phase flame retardant mechanism: APP decomposes under heat to produce non combustible gases such as NH3, NO, and water vapor. These gases can not only reduce the concentration of combustible gases in the air, but also expand the carbon layer in the condensed phase, reducing the heat and material transfer rate; In addition, the phosphoric acid derivatives decomposed during the combustion process of the APP will undergo disproportionation reactions to generate HPO ·, PO2 ·, and PO · radicals, which can capture the H · and OH · radicals generated by the polymer chain reaction to quench and reduce heat release.
Usually, the condensed phase flame retardant and gas-phase flame retardant of APP work together, but the gas-phase flame retardant of APP requires the consumption of phosphoric acid to form free radicals. As the phosphoric acid content decreases, the total amount of porous carbon layer also decreases, and the formed carbon layer decomposes, reducing the effectiveness of condensed phase flame retardant. Therefore, in some cases, the APP only undergoes condensed phase flame retardancy, and the flame retardant effect is actually improved.
Sichuan Taifeng New Flame Retardant Co., Ltd was founded in 2001, mainly engaged in phosphate chemical products. In 2011, in order to keep up with the national economic trend and seize new opportunities, the company focused on ammonium polyphosphate and set up R&D department special for halogen-free flame retardant.
Our manufacturing site is located in Shifang city, Sichuan province, which is one of the most important phosphate production base in southwest China. It provides superior development conditions for the company with rich phosphate resources and complete support facilities.
Ammonium polyphosphate(APP) and modified and compound based on APP are our main products. They are used throughout many industries, such as fireproof coating, textiles, paper, masterbatch and etc. We have a national and global sales network to worldwide.
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