Functionalization of polyorganophosphazenes. VII. Photooxidative stabilization of aryloxy-substituted polyorganophosphazenes induced by grafting HALS groups through anhydride moieties

Abstract

ABSTRACT:In this article, the general procedure for stabilizing polyorganophosphazenes against the damage induced in these substrates by photooxidation reactions under accelerated conditions is explored. This method is based on the preventive grafting of succinic anhydride groups onto selected polyphosphazenes induced by light excitation, followed by the reaction of the functionalized phosphazene substrates with aminoterminated HALS groups. HALS moieties, in fact, are able to strongly inhibit the photooxidation of phosphazene films under accelerated conditions even when randomly attached to the polyphosphazene materials in very low amounts.

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“…Ekman et al13 first grafted m ‐isopropenyl‐α,α‐dimethyl benzyl isocyanate and styrene onto PP, and then the isocyanate moiety of the graft copolymer was allowed to react with the HALS 4‐amino‐2,2,6,6‐tetramethyl piperidine. Minto et al14 grafted succinic anhydride groups onto selected polyphosphazenes, and this was followed by the reaction of the functionalized phosphazene substrates with amino‐terminated HALS groups.…”