Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique
UMR 5623

Sasha Ivanchenko, PhD student at IMRCP, has defended his thesis on novel synthetic strategies for radical ring-opening polymerization

Sasha carried out his research in the P3R team at the IMRCP laboratory.

On 6th of March, he defended his thesis entitled: "Novel strategies of synthesis for radical ring-opening polymerization"

For the first time, a comprehensive mechanistic investigation of the reactivity of thionolactone derivatives in radical ring-opening copolymerisation (rROcoP) and the degradability of obtained copolymers is reported.
He presented the access to three different classes of thionolactone-like monomers, which are able to radically copolymerise with vinyl esters, (meth)acrylates and styrene. A structure-reactivity relationship study in rROcoP has been conducted for thionolactones and thionoglycolides. For unsubstituted thionolactones, the fraction of ring-opened units follows the order 7>16>5>6 membered thionolactone. DFT calculations in combination with experimental results have shown the importance of the stabilisation of the intermediate ring-retained radical for the thionolactone reactivity. For thionoglycolides the effect of the substituent in the β position to the C=S is revealed while the stabilisation of ring-opened radical plays a less important role. A chain-terminating effect was found for thionolactones and thionoglycolides in the copolymerisation with vinyl monomers.
The identified presence of both ring-opened and ring closed units was evidenced by polymer degradation studies. A substantial decrease in Mw after chemical degradation was observed for obtained copolymers from vinyl pivalate, t-butyl acrylate and styrene. Orthogonal degradability is reported for thioketal and thioester links incorporated in the copolymer backbone. The degradation profile of copolymers was characterised with the help of model compounds mimicking degradable units in the copolymer.

This work can be used as a guide for the design of on-demand degradable copolymers with a variety of commodity monomers.

Highlights of the thesis:

Sasha is co-inventor of a patent and he is participating in a technology maturation project financed by Toulouse Tech Transfer on the technologies resulting from his thesis work.
Also, he has published 3 articles in the journal Polymer Chemistry.

Many congratulations to Sasha for the quality of his work!



2023 IMRCP