Reactions between Hexachlorocyclotriphosphazene and Hexamethylcyclotrisiloxane: Polymerization, Ring Cleavage, and Cross-Linking

摘要

The reactions between (NPCl2)3 and (OSiMe2)3 at 250 C have been investigated. Three main processes occur: siloxane ring-ring equilibration, homopolymerization of (NPCl2)3 to high polymeric (NPCl2)n, and siloxane skeletal cleavage by P-Cl bonds to yield cyclic phosphazenes bearing one or two omega-chlorosiloxane side groups. The formation of phosphazene polymers cross-linked by P-O-P bonds also occurs at later stages of the reaction. Alpha Omega-Dichlorosiloxanes are liberated in this latter process. Similar reactions are evident when (NPCl2)3 reacts with (OSiMe2)4 or (Me3Si)2O. The interconnected reaction pathways that lead to these products are discussed.