3, 4 This is especially true for polymers having a backbone consisting of carbon-carbon bonds, that do not allow chemical degradation by hydrolysis. For example, polystyrene is a very interesting common plastic due to its thermal properties and its resistance to corrosion but it could be found intact after 32 years in soil. Another example is polyacrylates that are widely used in adhesives, textiles and lubricating oils for their properties of flexibility, low glass transition temperature and tunable hydrophobicity. Since it is very difficult but also very expensive (REACH registration, etc.) to design brand-new materials that could both have the desired properties (mechanical, thermal, solvent resistance, etc.) and that are at the same time either recyclable and/or biodegradable, transforming already known materials to make them biodegradable/recyclable is more interesting. This approach relies on the introduction of labile bonds into the polymer backbone. The degradation could thus occur from these weak bonds leading to oligomers that could be easily chemically recyclable and/or bio-assimilable. One technique for producing this kind of material is the radical ring-opening copolymerization (rROP) of a cyclic monomer with a common vinyl monomer. The polymerization occurs via the addition of radicals onto cyclic monomers bearing an exo-methylene function or equivalent groups followed by a fragmentation of the intermediate cyclic radical to afford a new radical capable of propagating with a vinyl monomer. This mechanism results in the incorporation of heteroatoms into the C-C backbone and consequently in the introduction of cleavable bonds in the copolymer backbone (Figure ). The main family of cyclic monomers used in rROP is cyclic ketene acetal (CKA). These cyclic monomers have been extensively studied during the last few years, and are very efficient for the copolymerization with vinyl monomers such as vinyl ether derivatives and vinyl acetate. In the case of the copolymerization with (meth)acrylate and (meth)acrylamide derivatives, the difference in reactivity between the comonomers led to a lower insertion of the CKA compared to the initial feed ratio and a compositional drift at high conversion.