Synthesis And Properties Of Oxadiazole Containing Polyphosphazene

Polyphosphazenes are inorganic polymers with a backbone of alternating phosphrous and nitrogen atoms, side groups linked to the phosphorus atoms. Its chemical and physical properties varies with kinds of side group.First, hexachlorocyclotriphosphazene was prepared in chlorobenzene, the reaction mechanism was discussed here, and the product was characterized by melting point determinating instrument, FT-IR and 31PNMR.Polydichlorophosphazene was prepared by ring-opening polymerization of hexa- chlorocyclotriphosphazene according to accept procedure. And the influence factors of the polymerization, such as, heating resource, polymerization time, temperature and catalysts were also discussed. It was found that Cu(PPh3)3Br, Cu(PPh3)3Cl, Zn(PPh3)3Cl2, pyridine hydrochloride and Alq3 could initiate the polymerization, but caused cross linking reaction. It was also found that PPh3 could inhibit the polymerization. The polydichlorophosphazene was characterized by 31PNMR.Then the model molecule, oxadiazole-containing cyclotriphosphazene was synthesized. The compound was characterized by FT-IR and 1HNMR, tested by UV-Vis spectrum, fluorescence spectrum, DSC and TGA. The results showed that this compound was steady until 350℃with a absorption peak at 286nm and a emission peak at 356nm in chloroform.At last, oxadiazole-containing polyphosphazene was synthesized. The polymer was characterized by FT-IR, 1HNMR and GPC, tested by UV-Vis spectrum, fluorescence spectrum, DSC and TGA. The results showed that the molecular weight of the polymer was Mw=1.03×104 g/mol,Mn=7.91×103 g/mol,D=1.30. The polymer had two kinds of glass transition temperature: 92℃and 133℃. It was steady until 200℃with a absorption peak at 284nm and a emission peak at 360nm in chloroform.