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Cong, Lianhui

Chemistry

2005

PhD

Several cyclotriphosphazenes with multiple exocyclic unsaturated groups, N₃P₃(OC₆H₄CH=CH₂)₆ (HSCP), N₃P₃(O(CH₂)₄OC(O)C(CH₃)CH₂)₆ (HMBCP), and N₃P₃(OCH₂C(CH₃)(CH₂OC(O)C(CH₃)=CH₂)CH₂O)₆ (HSMCP), were synthesized and conversions to crosslinked and hyperbranched polymers by copolymerization with styrene or methyl methacrylate were investigated. The thermal stability of the copolymers improved with increased incorporation of the cyclophosphazene monomers. Furthermore, HMBCP was employed as a photoresist in photolithography leading to etched patterns with high resolution. Polyphosphazenes [N=P(OC₆H₅)₂₋x(OC₆H₄CH=CH₂)x]n, with various incorporations of styryloxy side groups and their polysiloxane graft polymers were synthesized, and their thermal behaviors were studied in detail. The cyclo- and polyphosphazenes with 4-ethynylphenoxy side groups, N₃P₃(OC₆H₄C-=CH)₆ and [N=P(OC₆H₅)₂₋x(OC₆H₄C=CH)x]n, respectively, were synthesized and characterrized. The conversion of these cyclo- and polyphosphazenes to organometallic phosphazenes via reactions with cobalt carbonyl is presented. Thermal decomposition of the cobalt containing polymers leads to dispersed metal particles in a polymeric matrix.