Exploiting retro oxa-Michael chemistry in polymers

One way to obtain recyclable polymeric materials is to include reversible bonds in polymers. Herein, we study the reversibility of the oxa-Michael reaction and explore its scope and limitations in simple model systems and further in linear polymers as well as in polymer networks. The results show that the retro oxa-Michael reaction of sulfone, acrylate or acrylonitrile based adducts is considerably fast at elevated temperatures (>100 °C) if Brønsted bases (e.g. KOH) are used as catalysts. Under these conditions, alcohols can easily be exchanged in oxa-Michael adducts within minutes. Furthermore, poly(ether)s derived from oxa-Michael reactions can be depolymerized into small fragments in the presence of alcohols and show self-healing characteristics in networks.