Organic polymers with cyclophosphazene side groups: Influence of the phosphazene on physical properties and thermolysis

Polystyrene and poly(methyl methacrylate) copolymers with cyclophosphazene side groups have been prepared by the reactions of azidocyclophosphazenes w ith diphenylstyrylphosphine residues in the copolymer structures. The cyclo phosphazene pendent groups were present in from 1 to 100% of the monomer re sidues in polystyrene and from 2 to 20% of the repeating units in poly(meth yl methacrylate). In both systems, the cyclophosphazene side units lowered the T,roughly in proportion to their concentration in the macromolecules. T he presence of similar to 10% of cyclophosphazene-bearing monomer residues markedly reduces the combustibility of both polystyrene and poly(methyl met hacrylate). The mechanism of fire retardance is discussed.