Abstract
We report the preparation of degradable polymer networks by conventional free radical copolymerization of n-butyl acrylate with a crosslinker (1 mol%) and dibenzo[c,e]oxepane-5-thione (DOT) as a strand-cleaving comonomer. Addition of only 4 mol% of DOT imparts the synthesized networks with full degradability by aminolysis, whereas gels with less DOT (2-3 mol%) cannot be degraded, in excellent agreement with the recently proposed reverse gel-point model. Importantly, even though DOT significantly slows down the polymerization and delays gelation, it has a minimal effect on physical properties of the networks such as shear storage modulus, equilibrium swelling ratio, glass transition temperature or thermal stability.
Version notes
New sample with 3 mol% of DOT has been analysed and added. Mass loses upon degradation have been measured and added. Theoretical model has been refined.
Content

Supplementary material

Supporting Information: Fully degradable polymer networks from conventional radical polymerization of vinyl monomers enabled by thionolactone addition
Experimental details, kinetic measurements, additional GPC traces, 1H NMR spectra and digital images of the gels.