Cationic Grafting of Vinyl Ether on Chlorinated Polypropylene for Long‐Chain Branched Polypropylene

ABSTRACT Commercially available chlorinated polypropylene was used as a substrate for the aluminum chloridecatalyzed cationic graft polymerization of isobutyl vinyl ether, resulting in long‐chain branched polypropylene graft copolymers with poly(isobutyl vinyl ether) side chains. The successful grafting reaction and the targeted architecture were confirmed by 1 H NMR and 13 C NMR analyses. The introduction of grafted branches significantly modified the melt viscoelastic behavior, leading to enhanced melt elasticity and increased viscosity over a wide frequency range. In addition, the water contact angle decreased with increasing grafting degree and was further reduced after hydrolysis, indicating improved surface wettability and higher surface polarity. This cationic grafting strategy provides an efficient route to tailor both rheological properties and surface performance of polypropylene based materials.