Ring Expansion and Equilibration in Organophosphazenes, and the Relationship to Polymerization
PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF CHEMISTRY
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A series of cyclic trimeric phosphazenes that bear both halogen and organic side groups have been found to undergo ring expansion-equilibration reactions at elevated temperatures. Compounds non-gem N3P3F5CMe3, N3P3F5Ph, N3P3F4 CMe32,N3P3F4Ph2, hexamers, and in some cases, heptamers, octamers, and nonamers when heated. The cyclic tetramers NPC1Me4 and NPC1Et4 also equilibrate to a range of cyclic species that range from trimer to hexamer. Several of these equilibrations also lead to the formation of high polymers. The results are discussed in terms of possible mechanisms for ring-ring equilibration and polymerization. Keywords Synthesis Mechanisms Thermal stability.
- Polymer Chemistry