Versatility of Organocatalyzed Atom Transfer Radical Polymerization and CO2-Switching for Preparing Both Hydrophobic and Hydrophilic Polymers with the Recycling of a Photocatalyst

Abstract

A new approach was designed to prepare both hydrophobic and hydrophilic polymers by organocatalyzed atom transfer radical polymerization (O-ATRP). The method is based on using a recoverable photocatalyst whose properties can be switched using only CO2 addition and removal as triggers. The effectiveness of the CO2-switching approach in O-ATRP is demonstrated using a new CO2-switchable photoinitiated catalyst, which can be extracted from the polymer and reused. The residual catalyst in the polymer is reduced to less than 15 ppb. The feasibility of recovering and reusing the photoinitiated catalyst for subsequent polymerizations is also established.