What are compound flame retardants?

The mixed system is selected to obtain the co-effect effect of flame retardancy. Most flame retardants can show their effects according to a variety of processes.

1. Compounds containing halogens and phosphorus

Resistance too agent containing phosphorus, can be turned into phosphate under high temperature and oxidant, metaphosphate, polyphosphoric acid. Have the effect of dehydrating oxygen polymer, carbonation, forming a protective layer surface coking, isolated from oxygen and fuel, which is a kind of process, its resistance of nun when mixed with halogen compounds using, can form two kinds of phosphorus and halogen resistance compounds. Such as PBr3 PBrs, POBr, etc, this kind of halide than major, can search on the flame surface cover, have the effect of oxygen isolation, diluent can be tender, at the same time it gets easier than with the activity of · OH,Therefore, compared with HX alone, HX has a stronger ability to capture free radicals.

2. Mixture of halides and antimony trioxide

, O, itself shine effect, due to its melt temperature is higher than most of the light-off temperature of the polymer, which is according to transfer process also is unable to provide fire prevention role. When used with mixed halide, can produce A series of reaction, the formation of halogenated antimony (CI3) chloride antimony oxide ((OCI), these substances under the light-off temperature is gaseous, into A layer and flame burning, can dilute the concentration of the gas, nun can participate in capturing h. and HO again. Such as the activity of free radicals. In addition, the solid content also have similar phosphoric acid to promote the effect of carbonization.

Borides and other compounds

Boron and its derivatives have the property of being easy to melt, that is, to form protective layers during melting. For example, boric acid and metaboric acid melt at 170-250 ° c, at which temperature most polymers are not dissimilar, so they can be used as flame retardants.Zinc fumarate and calcium fumarate are commonly used in industry to make fire retardant coatings, but their high hygroscopicity limits their application.

For high molecular weight organoborate compounds, it has been recommended as flame retardant, it has very good compatibility and low extractability.