Epoxy resins rank among the most significantly used thermosets, showing high thermal and mechanical properties. Unfortunately, current polymerization processes to reach these properties are energy-intensive, characterized by high temperatures and long processing duration. Addressing this problem, recent years have witnessed the emergence of curing methods under mild and ecofriendly conditions, aligning with societal and ecological challenges. Mild conditions were delineated in this review as a polymerization without solvent and at temperatures not exceeding 80 °C. This work highlights three methods, by focusing on research works from 2015 to date: i) polyadditions via step-growth ring opening polymerization, ii) photopolymerization leading to homopolymerization of bio-based monomers and iii) redox polymerization achieved through the release of cations or acidic protons species, initiating the cationic polymerization. In the context of ecofriendly conditions, the replacement of bisphenol-A present in many epoxy monomers is also a huge challenge to keep both good mechanical properties and fast polymerization kinetics. In this context, this review aims at underlining the increasing importance of epoxy curing under mild conditions, in possible combination with bio-based monomers for bisphenol-A replacement and to guide both researchers and industries to explore and develop new curing systems.

Magnetic resonance imaging (MRI) is recognized as the most powerful clinical imaging modality due to its ability to produce detailed three-dimensional anatomical images and high spatial resolution in a non-invasive manner without the use of harmful radioactive nuclides or ionizing radiation. Conventional small molecule contrast agents (CAs) for MRI, such as paramagnetic transition metal ion chelates or iron oxide nanoparticles, are limited by lower relaxivity, shorter blood circulation time and their potential toxic effects. Functional polymers capable of being detected by MRI have therefore become attractive, offering the unique advantage of pre-design due to their chemical flexibility, structural diversity, and tailoring of properties. Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a powerful tool that not only enables the precise formation of macromolecular building blocks with complex structures and functions, but also provides a direct method for preparation of polymeric nanoparticles with multiple morphologies suitable for biomedical applications. In addition, when combining RAFT polymers with inorganic/metallic complex nanocomposites, the polymer provides the ability to encapsulate therapeutic molecules, thereby combining diagnostic and therapeutic functions in what is known as a theranostic nanomedicine. In this review, we highlight recent advances in the development of multifunctional polymers as MRI CAs designed and prepared by RAFT polymerization and their performance in diagnosis and treatment of disease. In addition, the review will address the challenges and future opportunities for RAFT-mediated MRI-based theranostics in guiding the treatment of diseases including malignant tumors.