Preparation of semifluorinated poly(meth)acrylates by improved photo-controlled radical polymerization without the use of a fluorinated RAFT agent: facilitating surface fabrication with fluorinated materials†
Fluorinated polymers have attracted increasing attention in a broad range of areas, and access to such polymers with low-cost agents and simple conditions would offer improved application opportunities for both academia and industry. An efficient preparation of a variety of semifluorinated poly(meth)acrylates without the use of a fluorinated iniferter/initiator or a solvent via photo-controlled radical polymerization is herein reported. The polymerizations can be efficiently switched between “ON” and “OFF” both in the presence and absence of a photoredox catalyst in response to visible light while maintaining a linear increase in polymer molar mass with conversion and first order kinetics. As demonstrated with gel permeation chromatography analysis and kinetic investigations, catalyzed photopolymerizations provide polymers with narrower molar mass distributions, shorter induction times and higher conversions in comparison with catalyst-free reactions, representing a reliable and efficient synthetic approach starting off from fluorine-free agents. The high chain-end fidelity of the polymer was confirmed by MALDI-TOF-MS measurements and chain-extension experiments. Furthermore, the method using fluorine-free iniferters facilitated surface fabrication with fluoropolymers, providing highly hydrophobic materials. These results illustrate the simplicity and utility of the light-controlled polymerization of semifluorinated monomers.