Synthesis And Characterization Of Phosphazenes Efficient And Environmentally Friendly Flame Retardant

Phosphazenes, which is based P, N-based chain, alternating single and double bonds, is a new organic-inorganic composite compound. Because of the two living chlorine atoms on the phosphorus atoms, phosphazenes can be substituted by a variety of organic nucleophiles to obtain excellent mechanical properties and chemical properties, such as high temperature resistance, corrosion resistance, abrasion and fire retardant. Phosphazenes as an indispensible member of polymer materials chemistry has become a hotspot of current research.In this paper, hexacholrocyclotriphosphazene(HCCP) has been prepared by ourselves. Phosphazenes oligomer has been obtained by ring-opened polymerization. The optimal synthetic process was250℃for9h. When adding catalyst AlCl3existed, the optimal synthetic process was250℃for2h. Sodium ethoxide and hydroxyethyl acrylate (HEA) have been chosen to modify phosphazene oligomers. The optimal reaction condition was n(EtoNa):n(HEA):n(PDCP)=1:1:1.The first step in a reaction time of8h, and the temperature was70℃. The second step was0℃for9h. HCCP has been modified by ethoxy and hydroxyethoxy. The optimal synthetic process was n(HCCP):n(EtONa):n(HOCH2CH2ONa)=1:4:2, and the reaction time of first step was8h and second step was40h. The copolymer of polyethylene terephthalate (PET) and TEDECP has been synthesized by TDCP added in the polycondensation stage. Effects of the amount of the flame retardant added on its Limiting Oxygen Index(LOI) has been discussed. When the amount is2wt%of Terephthalic, LOI is30, and the concent of2wt%can reach the UL-94V-0level. The products have been characterized by FT-IR,31P-NMR,1H-NMR, MASS, TG, XRD, etc.