Surface modification of active metals through atom transfer radical polymerization grafting of acrylics

The objective of this work is to investigate the fundamentals of surface-initiated atom transfer radical polymerization (s-ATRP) on metal substrates. Acrylic polymers were grafted from active metal surfaces such as cold rolled steel (CRS), stainless steel (SS) and nickel (Ni) through s-ATRP. Severe deactivation was found with copper bromide bipyridine catalyst. Controlled polymerization with relatively low polydispersities, 1.18–1.35, was achieved using iron bromide triphenylphosphine catalyst. Polymer films up to 80nm in thickness were obtained within 80min. Grafting densities were estimated to be 0.58chains/nm2 for CRS-g-PMMA, 0.55chains/nm2 for Ni-g-PMMA, 0.18chains/nm2 for SS-g-PMMA, and 0.66chains/nm2 for SS-g-PDMAEMA. Electrochemical experiments were also carried out to measure the polarization resistance and corrosion potential of CRS-g-PMMA substrates. Metal surfaces with grafted brush polymer coatings showed significant corrosion resistance. This work demonstrated that the surface-initiated ATRP is a versatile means for the surface modification of active metals with well-defined and functionalized polymer brushes.