New Chiral Polyurethane Polymers Based on Functionalized Cyclotriphosphazenes

Abstract

Novel hybrid polymers using chiral phosphaznes were prepared in the following way: Starting from hexachlorocyclofriphosphazene, N₃,P₃,Cl₆, chelating phenolates were introduced by reaction with the corresponding sodium salt. Thus, reaction with two equivalents of atropisomeric binaphtolate yields chiral lb in high yield. Subsequently, p-methoxyphenolates were reacted with the remaining PCl₂, functionality and the p-MeO groups were converted to hydroxy groups [I] to give bifunctional 2a,b. Finally, polyadditions to diisocyanates lead to new cyclolinear polyurethanes 3a,b which were characterized by thermal analysis [2,3]. The T₁₀, is 320 and 240°C for 3a and 3b respectively. In particular, the chifal polymer 3b [α=lll°] may have interesting properties as catalyst support.