Visible-light-mediated, additive-free, and open-to-air controlled radical polymerization of acrylates and acrylamides

Oxygen tolerance in controlled radical polymerizations has been an active field of study in recent years. Herein, we report a photocontrolled, additive-free iniferter polymerization that operates in completely open vials utilizing the “polymerizing through oxygen” mechanism. Trithiocarbonates are directly activated with high intensity 450 nm light to produce narrowly dispersed (M[subscript w]/M[subscript n] = 1.1–1.6) polyacrylates and polyacrylamides. Living behavior is demonstrated through chain extension, block copolymer synthesis, and control over molecular weight through varying the monomer : iniferter ratio. A slight increase in induction period is observed for the open vial polymerization compared to the air-free reaction, but polymers with similar M[subscript n] and M[subscript w]/M[subscript n] values are produced after 30–60 minutes of irradiation. This system will provide a convenient platform for living additive manufacturing because of its fast reaction time, air tolerance, wide monomer scope, and lack of any additives beyond the monomer, iniferter, and DMSO solvent.National Science Foundation (U.S.) (CHE-1629358)National Science Foundation (U.S.). Materials Research Science and Engineering Centers (Program) (Award DMR 14-19807)National Institutes of Health (U.S.) (1F32GM126913-01A1