Synthesis and characterization of aromatic cyclolinear phosphazene polyetherketones containing bis-spiro-substituted cyclotriphosphazene unit

A novel monomer, 2,2-bis-(4′-fluorobenzoylphenoxy)-4,4,6,6-bis[spiro-(2′,2″-dio xy-1′, 1′-biphenylyl)] cyclotriphosphazene, was synthesized and polymerized with 4,4′-difluorobenzophenone as a comonomer and 4,4′-isopropylidenediphenol or 4,4′-(hexafluoroisopropylidene) diphenol in N, N-dimethylacetamide at 162°C for 4 h to give two series of aromatic cyclolinear phosphazene polyetherketones containing bis-spiro-substituted cyclotriphosphazene groups. The structure of the monomer was confirmed by ¹H, ¹³C, and ³¹P NMR. The effect of the incorporation of the bis-spiro-substituted cyclotriphosphazene group on the thermal properties of these polymers was investigated by DSC and thermogravimetric analysis.