Internal catalysis on the opposite side of the fence in non-isocyanate polyurethane covalent adaptable networks

Within the context of covalent adaptable networks (CANs), we developed in this study a novel methodology to provide non-isocyanate polyurethane-based CANs with embedded tertiary amines that serve as internal catalytic moieties for dynamic bond exchange processes. For CAN design, made use multifunctional N-substituted 8-membered cyclic carbonates are ring-opened by macromolecular amines. Several model reactions were conducted investigate transcarbamoylation at elevated temperatures and assess influence within urethane structure. This led us design polyurethane wherein position catalyst was changed respect previous reported polyhydroxyurethane CANs, while maintaining close proximity carbamate linkages. It is shown positioning change still resulted an effect on reactions, hence providing better understanding role catalysts during reprocessing networks. Moreover, experiments thermomechanical investigations (re)processed allowed identify occurrence competing involving dissociative mechanism giving rise urea formation, which significantly impacts materials’ reprocessability properties.