The Synthesis And Properties Of New Flame Retardants

This paper systematically reviews the properties of flame retardants, the mechanisms of flame retardants and related research and development. 7 new flame retardants are synthesized according to the burning theory of polymeric materials, the mechanism of Phosphorus, Bromine, Nitrogen and carbonizing theory.Firstly, three new flame retardants of organophosphates are synthesized, each of which contains three flame-retarded elements of Phosphorus, Bromine, Nitrogen. They are New Flame Retardant (I) O-(2,6,7-trioxo-l-oxyphosphabiscyclo[2.2.2]octane-4-methylene)-O-2,3,-(dibromopropyl)phosphoric melamine salt, New Flame Retardant (II) O-(2,4,6-tribromophenyl)phosphoric melamine salt, and New Flame Retardant (III) 0,O-di(2,4,6-tribromophenyl)phosphoric melamine salt. Then it preliminarily discusses the resulting effects caused by reaction temperature, reaction time, solvents, catalysts etc, confirmes the structure of the compounds by elements analysis, NMR and IR spectra, preliminarily evaluates the properties of the new flame retardants by TGA and its application in the unsaturated resins experiments. The results proved that not only Phosphorus, Bromine, Nitrogen in each molecule have well mutual synergy of inflaming retarding, but also the properties of flame retardants will be improved if the carbonized structure is introduced to the molecule with Phosphorus, Bromine, Nitrogen. New Flame Retardant I is best with the above-described advantages.Secondly three flame retardants not belonging to salt are synthesized, each of which contains three flame-retarded elements of Phosphorus, Bromine, Nitrogen too. They are New Flame Retardants (IV)l,4-phenylene-O-(2,4,6-tribromophenyl) phosphamide ester, New Flame Retardant (V)l,3-(2,2-dibromomethyl)propylidene-O-(2,4,6-tribromophenyl) phosphamide ester, New Flame Retardant (VI) 1,3-(2,2-dibromomethyl)propylidene-O-(2,6,7-trioxo-1 -oxyphosphabiscyclo[2.2.2]o ctane-4-methylene) phosphamide ester. Then it preliminarily discusses the effects caused by the catalyst and the order of adding the stuffs, confirms the structure of the compounds by the elemental analysis, NMR, IR spectra, discusses the thermal stabilities of the flame retardants by TGA, preliminarily evaluates the properties of the formedflame retardants by applying to unsaturated resins experiments. The results proves that New Flame Retardant VI (added 15%) is the best in flaming retarding, because the molecule contains carbonizing sources of rigid structure (double ring), which can produce graphitoid carbonizing layer of thermal insulation and oxygen-suppressed. Hence the flame retardancy will be improved if the carbonized structure, especially rigid structure is introduced to the molecule with Phosphorus, Bromine and Nitrogen. New Flame Retardant V with the most amount of bromine and carbonized structure is the worst, because its inflame retarding mechanism is not mostly based on the carbonization mechanism, and its molecule has the fatty chain of non-rigid structure, which causes its thermal stabilities inferior to those of New Flame Retardant IV with benzene ring. When added less New Flame Retardant IV, V and VI with proper amount of melamine, flame retardancy of unsarurated resin are getting better, which further shows that the synergism among Phosphorus, Bromine and Nitrogen will enhance the inflaming retarding effect. Especially when Flame Retardant VI and melamine are added, the OI would be above 30%, which shows that the Nitrogen proportion is very important to the flame retardants using carbonization flaming retarding mechanism.Finally a new inrumescent flame-retarded monomer (New Flame Retardant VK)l,3-phenylene-O-(2,6,7-trioxo-l-oxyphosphabiscyclo[2.2.2]octane-4-methylene)pho sphate is synthesized. Then it confirms the structure of the compound by the elemental analysis, IR spectra, shows its maximum decomposition temperature at 356癈 higher than any other reported inrumescent flame retardants. The application experiment shows that it would become an efficient non-halogen inrumescent flame retarda...