Insights Into the Kinetics and Chain Extension in the Synthesis of Cholesterol‐Terminated Poly(<i>Tert</i>‐Butyl Acrylate) via Controlled Radical Polymerization

ABSTRACT Cholesterol‐terminated poly(acrylic acid) was prepared through a simple two‐step method, consisting of the reversible‐deactivation radical polymerization of tert ‐butyl acrylate with a cholesterol‐based initiator and acidic hydrolysis of the tert ‐butyl group. The Cu(0)/Cu(II) catalytic system allowed the controlled polymerization of tert ‐butyl acrylate with narrow dispersity in less than an hour. Kinetic studies revealed that the initial catalyst ratio influences the polymerization time by means of an induction period that increases with the [Cu(II)] 0 /[Cu(0)] 0 ratio. The effect of nitrogen purge and freeze‐pump‐thaw cycles was assessed, and both were found to be equally effective in the system deoxygenation. The synthesized polymers exhibited a high degree of chain‐end fidelity, as evidenced by the results of chain extension experiments. This makes the system interesting for the formation of block copolymers with cholesterol‐termination, broadening its range of applicability.