Study On Synthesis And Application Of New Phosphonyl Heterocyclic Phenylphosphonate Flame Retardant

In recent years,flame retardants are rapidly developed,and consequently their applications draw a lot of attention.However,as modern people's living standards have improved more,environmental awareness of people has been strengthened,and various laws and regulations have been continuously introduced and improved,the demand for a new type of highly efficient green flame retardant is more and more urgent.Phosphorus flame retardants have non-toxic,efficient,cheap and other advantages,and the C-P bond that they contain can help the compound structure more stable;Silicon-based flame retardants have high flame-retardant efficiency and the excellent performance of antimelt-dripping;Sulfur element is also a good flame-retardant element,and it has good synergy with phosphorus.As a result,if the P,Si and S elements can be combined into a molecular structure,such a new flame retardant is bound to be develop and promot successfully.In this article,we used hydroxymethylphosphono heterocyclic phenylphosphonate and hydroxymethyl thiophosphoryl heterocyclic phenyl phosphate as two kinds of main raw materials and nine kinds of materials respectively diphenylphosphinyl chloride,dichlorophenylphosphine,phosphorus oxychloride,trimethyl chlorosilane,dimethyldichlorosilane,methyltrichlorosilane,silicon tetrachloride,trichlorovinylsilane and allyltrichlorosilane synthesized four series.These 12 compounds had not been reported.The synthesized product has the following features or advantages:(1)The synthesized products contain cyclic organic phosphine structure with C-P bond,which can make the product structure very stable and suitable for high-temperature processing;(2)P,Si and S three elements they contain are according to their own flame retardant mechanism to synergistic flame retardant,greatly improving the flame retardant effect;(3)Two kinds of these products which contain alkenyl groups are reactive flame retardants that can be used as additive or add-reactive flame retardants.They can also be used as reactive intermediates to copolymerize with other monomers for synthetic flame retardant material with excellent performance.Another,they can also be polymerized by itself to obtain an easily dispersible polymer flame retardant.In this article,the above 12 compounds containing P,Si or S flame-retardant elements were synthesized.And then,we characterized the structure of the products by FTIR?~1H-NMR and other techniques,The obtained spectrum analysis results showed that the molecular structure of the products were consistent with the theoretical compound.Then through the TG-DTA we could find the products have good thermal stability and high remaining carbon rate.At last,the flame retardancy tested by limiting oxygen index and vertical burning test results show that,12 kinds of products have good flame retardant and charring effect.