Ultra-High Molecular Weights via Aqueous Reversible-Deactivation Radical Polymerization

Relying solely on mild UV irradiation of thiocarbonylthio compounds in the presence of vinyl monomers, a new avenue to well-defined ultra-high-molecular-weight (UHMW) polymers has been developed. Through the use of aqueous conditions, well-controlled UHMW polymers that are unprecedented for controlled radical polymerizations have been achieved. This photomediated polymerization approach reaches number-average molecular weights in excess of 8.00 x 10(6) g/mol with degrees of polymerization above 85,000, making these, to our knowledge, the highest-molecular-weight polymers ever achieved via reversible-deactivation radical polymerization. In many cases, well-defined UHMW polymers can be obtained in minutes. The utility of the technique is further demonstrated through the synthesis of block copolymers, enabling access to a new field of well-defined UHMW materials.