Vitrimers: one step towards a greener future for the composite industry?

The commercial applications of polymers produced by reversible-deactivation radical polymerization are reviewed here.

Narrowly distributed poly(N-vinyl caprolactam) obtained by the MADIX/RAFT process was used for the preparation of novel thermoresponsive gold nanoparticles presenting a sharp reversible response to temperature, which can be easily modulated near the physiological temperature by simply changing the polymer molecular weight or concentration.

This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of the range, many vinyl esters have been considered in order to tune various polymer properties, in particular, solubility in supercritical carbon dioxide (scCO₂). A special emphasis is given to novel poly(vinyl alkylate)s with enhanced solubilities in scCO₂, with applications as reactive stabilizers for dispersion polymerization and macromolecular surfactants for CO₂ media. Other miscellaneous uses of poly(vinyl ester)s synthesized by RAFT, for instance as a means to produce poly(vinyl alcohol) with controlled characteristics for use in the biomedical area, are also covered.

We pushed back the limits of molar mass control in aqueous RAFT/MADIX polymerisation through a fast and quantitative gel polymerisation of a series of acrylamido monomers. Unprecedentedly high M_n up to 10⁶ g mol⁻¹ with low dispersities (Đ < 1.2) was achieved in homopolymerisation, statistical and block copolymerisation of a selection of acrylamido monomers such as AM, DMA, AMPS and NIPAM. The reasons for access to an abnormally high kinetic chain length in the presence of a RAFT/MADIX agent are discussed.