is important for tuning the resulting material prop- ties, ranging from elastomeric to thermoplastic and even highly crosslinked duroplastic structures and networks. On the basis of the thermal reversib- ity, new materials with highly tunable properties can now be prepared, - ing able to change their mechanical and optoelectronic properties with very smallchangesofexternalstimuli. Thusthe?eldofhydrogen-bondedpolymers forms the basis for stimuli responsive and adaptable materials of the future.