Smoke suppression technology of plastics
DATE：2021/4/30 8:45:28 / READ： / SOURCE：This station
Smoke suppression technology of plastics
Plastic sheet production line www.handern.com
More and more attention has been paid to the smoke suppression of polymers, especially the smoke suppression of polymers such as PVC, which has become a hot spot in the field of flame retardant technology. For more other polymers, smoke suppression has been compared with flame retardancy. At present, the main method to suppress the smoke generated by polymer combustion is to add smoke suppressant. Generally speaking, any substance that can capture smoke and prevent or inhibit the thermal decomposition of polymer to produce smoke can be called smoke suppressant. The latter tends to use physical methods to cool and insulate the polymer; In essence, it is to inhibit the thermal decomposition of polymer and reduce smoke. As for capturing the soot produced by polymer combustion, the effects of various smoke suppressants are different. Recently, a small amount of nano materials are used to suppress the smoke of polymer. The essence is to adsorb the smoke through the large specific surface area of nano particles and macro quantum tunneling effect, so as to achieve the purpose of smoke suppression. Plastic sheet production line www.handern.com
Smoke suppressants are divided into inorganic and organic. Inorganic smoke suppressants include CaCO3, Al (OH) 3, Mg (OH) 2, carbonaceous zinc borate, ammonium MoO3 octamolybdate, silicon compounds, minerals containing magnesium, aluminum and silicon, organic ferrocene and salts of organic acids. The smoke suppression principle of CaCO3 is that it can react (capture) with the hydrogen halide in the smoke to form CaCl stabilized by chloroethyl. The reaction formula is: friedcaco3 + 2HCl - → CaCl2 + H2O + 0o2 (g). As the above reaction is a solid gas heterogeneous reaction, it can only be carried out on the surface of CaCO and solid particles, so the particle size of CaCO and solid particles becomes a major factor in the smoke suppression effect. Only tiny particles with the same mass have much larger specific surface area. According to the above smoke suppression principle, all polymers that produce hydrogen halide during combustion, such as vinyl chloride, ammoniated polyethylene and neoprene, can use GOC as smoke suppression agent. When nano-sized Caco 2 is used to suppress smoke, the filling powder is only about 10%, which will produce ideal effect. Plastic sheet production line www.handern.com
The smoke suppression of Al (OH) 3 and Mg (OH): is mainly through the reaction characteristics. The endothermic capacity of the former is 153.4k/mol, and that of the latter is 45.6kjj. Their thermal decomposition reaction is one / mol. Such a large amount of heat absorption will greatly reduce the temperature of the compound and slow down its thermal decomposition. In addition, the exothermic water turns into hydrothermal gas, which can also dilute the combustible gas and smoke, playing a dual role of flame retardant and smoke elimination. Plastic sheet production line www.handern.com
Author：admin