Controlled RAFT Cyclopolymerization of Oriented Styrenic Difunctional Monomers

We describe the first example of controlled free radical cyclopolymerization of difunctional styrenic monomers. The newly designed monomers are obtained from the introduction of two 4-vinylbenzyl moieties as malonate or dialkylated malonate esters. The more sterically hindered monomer is particularly efficient in the cyclization and propagation processes, giving cyclopolymers, in diluted solvent conditions, with good yields and degrees of polymerization. In the presence of a suitable RAFT mediator, and, upon careful optimization of the solvent, temperature and monomer concentration, a linear increase in the number average molecular weight with conversion and low polydispersity indexes can be achieved.