Radical Copolymerization of Thionoglycolide and Derivatives\nfor Preparation of Degradable Vinyl Polymers

This\nstudy explores the copolymerization behavior of thionated\nglycolide derivatives with a focus on thionoglycolide (TGD). It was\nfound that TGD exhibits a nuanced reactivity profile, showing the\nhighest compatibility with styrene and <i>tert</i>-butyl\nacrylate (<i>t</i>BA). Kinetic analysis of the TGD/<i>t</i>BA system conducted at 100 °C in bulk demonstrated\ncomparable incorporation rates for both monomers. Furthermore, RAFT\ncopolymerization mediated by a trithiocarbonate RAFT agent resulted\nin a well-defined copolymer with <i>M</i><sub>n</sub> =\n13.4 kg mol<sup>–1</sup> and <i>Đ</i> = 1.2.\n2D-NMR microstructural analysis revealed that TGD was exclusively\nincorporated in its ring-closed S,O-thioketal form, suggesting a selective\n1,2-vinyl propagation mechanism. The degradability of the resulting\ncopolymers was also investigated, with NaOCl, NaOMe, and benzoyl peroxide\neffectively cleaving S,O-thioketal linkages.