Brief introduction of flame retardant

First, chlorine flame retardant: mainly chlorinated paraffin with high chlorine content; Second, brominated flame retardants: the main products are decabromodiphenyl ether, tetrabromobisphenol A, pentabromotoluene and hexabromocyclododecane. Bromine flame retardant has a wide range of applications and is one of the largest organic flame retardants in the world. Halogen flame retardant has the advantages of low consumption, high flame retardant efficiency and wide adaptability, but its serious disadvantage is that it generates a large amount of smoke and toxic and corrosive gases during combustion, which is very harmful. In recent years, the development of halogen-free flame retardant instead of halogen flame retardant has become the world flame retardant development trend. It has become one of the key research topics in the field of flame retardant in recent years to research and develop new flame retardants to reduce the amount of smoke and toxic gases when materials burn. The new flame retardant system produces less smoke when burning and does not produce toxic and corrosive gases. Halogen-free flame retardant additives are mainly phosphorus compounds and metal hydroxides. These two kinds of compounds, which do not volatilize and produce corrosive gases when burning, are called pollution-free flame retardants, and there are several new halogen-free flame retardants such as silicon flame retardants and nitrogen flame retardants. These new halogen-free flame retardants have become new products in line with the development trend of international standards. Inorganic flame retardant The amount of aluminum hydroxide AL(OH)3 accounts for more than 40% of the total amount of flame retardant. Aluminum hydroxide itself has three functions of flame retardant, smoke elimination and filling. Because it is non-volatile and non-toxic, and can produce synergistic flame retardant effect with various substances, it is known as a pollution-free inorganic flame retardant. However, aluminum hydroxide has the disadvantage of a large amount, which usually needs to be added more than 50% to have a good flame retardant effect. In order to overcome this shortcoming, granulation technology can be adopted to develop towards ultra-fine and narrow the particle size distribution; Improve the coating technology to improve its dispersibility in polymer; Treat by macromolecular bonding method, etc. Magnesium hydroxide Mg(OH)2 is a fast-developing additive flame retardant, which has low smoke, no toxicity, and can neutralize acidic and corrosive gases in the combustion process, so it is an environment-friendly green flame retardant. The flame retardant mechanism is similar to that of AL(OH)3. Compared with AL(OH)3, the decomposition temperature of Mg(OH)2 is 100-150℃ higher than that of AL(OH)3. mg (oh) 2 can be used for flame retardant of engineering plastics with processing temperature higher than 250C, and it can also promote the carbonization of polymer. however, to achieve a certain flame retardant effect, the addition amount of mg (oh) 2 should be above 50%, which has a great influence on the properties of materials. In order to reduce the amount of Mg(OH)2 added in polymer, one method is to fine Mg(OH)2 particles, and the other method is to modify the surface of Mg(OH)2 by coating technology to improve its compatibility with polymer.