Flame retardant agent is to improve an additive flame retardant flammable polymer. All plastics are flammable, made of plastic combustion caused the accident, has increasingly become a major social problem. The combustion of the polymer is a kind of complex and intense oxidation reaction, the combustion process is in constant heating external heat source, polymer first free radical chain degradation reaction with oxygen, produce volatile fuel, combustion will when it reaches a certain temperature and concentration, it put out, heat, which are degradable polymer further accelerated the degradation, and to generate combustible gas more, so that the combustion is more intense. 1.Flame retardant mechanism of flame retardant. Maintain the combustion has three elements: oxygen, heat and combustible, to prevent the plastic products of combustion, can take measures according to the three elements. Can produce non flammable gas or liquid with high boiling point heavier, covering on the surface of plastic products, the oxidation and combustible disconnection. Produce a large number of non flammable gas, can dilute the concentration and the concentration of oxidizing combustible gas area, so that the combustion to produce or continue. Flame retardants in heating can heat decomposition or heat sublimation, thus reducing the surface temperature of the polymer. Flame retardant can capture free radicals in the plastic products, thereby interrupting the chain reaction. 2.Classification of flame retardant. According to the method of using plastic flame retardant, the flame retardant is added and reaction type two kinds of additive flame retardant. This kind of flame retardant is added to plastics compound flame retardant elements or containing flame retardant elements. The characteristics of easy use, wide application range, now used in plastics flame retardant, the vast majority of additive type flame retardant. Flame retardants are commonly used: phosphate, phosphoric acid three toluene, phosphoric acid three, two aluminum hydroxide, antimony oxide, chlorinated paraffin, six bromobenzene, disrepair diphenyl ether etc.. Reactive flame retardant. This kind of flame retardant agent is flame retardant material or containing flame retardant material atoms, as one of the raw materials in plastics were prepared by a chemical reaction process, so that they become part of the plastic chain, so that the plastic flame retardant. Its characteristic is the flame retardant performance persistence, a smaller effect on plastic, but in general the higher the price, the use of less common. Mainly used for epoxy resin, polyurethane and other thermosetting resin. Reactive flame retardants are commonly used: halogen acid anhydride, such as phthalic anhydride four chloro two, four bromo adjacent benzene two anhydride, phthalic anhydride four bromo two etc.. |