Transcarbamoylation in Polyurethanes: Underestimated Exchange Reactions?

While transesterification has been largely explored by chemists, only a few studies comparatively dealt with its “sluggish cousin”, transcarbamoylation. Originally suggested 70 years ago to explain the stress decay observed at high temperature in polyurethane chemical networks, transcarbamoylation?also called transurethanization or urethane exchange?is still underexploited both organic and polymer chemistry. This is mainly related use of toxic reactants such as isocyanates tin-based catalysts involved during preparation molecular carbamates polyurethanes (PUs) well harsh conditions required observe exchanges transformations. Many have focused their interest alternatives isocyanates, underestimating potential transcarbamoylation produce, recycle, reprocess PUs (wastes). Perspective presents latest developments plausible future directions prepare sustainable PU-based materials using focus on covalent dynamic networks.