A Plasma-Initiated Graft Polymerization of Methyl Methacrylate in the Presence of a Reverse ATRP Catalyst

A plasma-initiated graft polymerization of methyl methacrylate (MMA) was carried out on the high-density polyethylene (HDPE) surface in the presence of the reverse atom transfer radical polymerization (RATRP) catalyst of CuCl2/2,2-bipyridine (bpy). The polymerization kinetics presented a linear relation with polymerization time. A well-defined PMMA brush was fabricated on the surface, evidenced by the linear growth of molecular weights with conversions and narrow polymer dispersity (D=1.31). Graft amounts were indicated to increase proportionally with the increase of conversions and molecular weights. Subsequently, a solvent-responsive surface was prepared by the block copolymerization of 2-hydroxyethyl methacrylate (HEMA) on the PMMA grafted surface. The polymerization is suggested to proceed via a RATRP mechanism, when plasma radicals could behave similarly as conventional radicals in forming dormant species.