Direct azidation of isotactic polypropylene and synthesis of 'grafted to' derivatives thereof using azide-alkyne cycloaddition chemistry

Abstract

Azido-functionalized isotactic polypropylene was prepared via the direct C-H azidation of a commercially available polymer using a stable azidoiodinane. Including imidazole or benzimidazole in the reaction mixture was found to significantly improve the yields of the post-polymerization modification. Although chain cleavage was observed, the methodology afforded high-molecular-weight (Mw>100 kDa) functionalized polypropylene containing up to 3mol% of azido groups and enabled access to polypropylene-graft-poly(ethylene glycol) copolymers via azide-alkyne cycloaddition chemistry.