Concurrent Thiol-ene Competitive Reactions Enable Reprocessable, Degradable and Creep-resistant Dynamic-permanent Hybrid Covalent Networks
Catalyst-free, solvent-free thiol-ene addition reaction was developed to produce dynamic-permanent hybrid cross-linked polymer from two simple components a tetrathiol and a divinyl ether in one pot. The tetrathiol and divinyl ether proceeded two competitive Markovnikov and anti-Markovnikov addition reactions simultaneously, and separately generated S,O-thioacetal cross-links and thioether cross-links. The dynamic feature of S,O-thioacetal cross-links imparts excellent malleability, reprocessability and degradability to the obtained network, and the permanent covalent thioether cross-links provide favorable high-temperature creep resistance. This work will broaden the thiol-ene chemistry, and provide a green method to achieve recyclable cross-linked polymers and covalent adaptable networks (CANs) or vitrimer-like materials with high-temperature creep resistance.