Ammonium polyphosphate (APP) is one of the most widely used flame retardants due to its excellent flame retardant properties. It is extensively used in various applications, such as wood, plastics, textiles, and coatings.
The flame retardant properties of APP are primarily attributed to its ability to release non-flammable gases when exposed to heat or fire. When APP is heated, it undergoes a complex decomposition process. Initially, the ammonium polyphosphate dehydrates to form polyphosphoric acid and ammonia.
Further decomposition of polyphosphoric acid leads to the formation of phosphoric acid, which is the ultimate flame retardant product.Phosphoric acid acts as a strong acid catalyst, causing the degradation of combustible materials and inhibiting the combustion process. It can react with combustible materials, such as hydrocarbons, to produce char residue. This char residue acts as a protective layer that hinders the release of flammable gases and prevents the spread of fire.
Furthermore, the presence of phosphoric acid leads to the formation of a condensed phase mechanism. This mechanism involves the formation of a protective layer, consisting of ammonium phosphates, on the surface of the material. This layer acts as a physical barrier, shielding the material from the heat and flame. It hinders the movement of heat and prevents oxygen from reaching the material, effectively suppressing the combustion process.
In addition to its flame retardant properties, APP also acts as a smoke suppressant. The release of non-flammable gases, such as ammonia and water vapor, dilutes the concentration of flammable gases in the surrounding atmosphere. This reduction in flammable gas concentration minimizes the risk of ignition and slows down the spread of fire.
Ammonium polyphosphate exhibits excellent flame retardant properties across a wide range of applications. Its mechanism involves the release of non-flammable gases, formation of char residue, and the creation of a protective layer. These mechanisms collectively work to delay the ignition time, suppress the combustion process, reduce smoke generation, and prevent the spread of fire.
In summary, ammonium polyphosphate (APP) acts as an effective flame retardant due to its ability to release non-flammable gases, form a protective layer on the material’s surface, and inhibit the combustion process. Its mechanism ensures the safety and protection of various materials from the hazards of fire.
Shifang Taifeng New Flame Retardant Co., Ltd is a professional ammonium polyphospahte (APP) facotry in China with 22 years of experieence.
Emma Chen
Sales manager
Tel/What’s up: +86 13518188627
Post time: Oct-16-2023
