Enzymatically synthesized vinyl ether-disulfide monomer enabling an orthogonal combination of free radical and cationic chemistry towards sustainable functional networks.

This work demonstrates a versatile and environmentally friendly route for the development of new orthogonal monomers that can be used for post-functionalizable polymer networks. A monomer containing both vinyl ether (VE) and cyclic disulfide moieties was synthesized via enzyme catalysis under benign reaction conditions. The bifunctional monomer could be polymerized to form macromolecues with differing architectures by the use of either cationic or radical photopolymerization. When cationic polymerization was performed, a linear polymer was obtained with pendant disulfide units in the side chain, whereas in the presence of radical initiator, the VE reacted with the disulfide to yield a branched structure. The monomer was thereafter used to design networks that could be post-functionalized; the monomer was crosslinked with cationic initiation together with a difunctional VE oligomer and after crosslinking the unreacted disulfides were coupled to with Rhodamine-VE by radical UV-initiation.