Synthesis, modification and properties of rosin-based non-isocyanate polyurethanes coatings

A series of bio-based non-isocyanate polyurethane (NIPU) coatings were successfully prepared via the ring-opening polymerization of rosin-based cyclic carbonate with amines. Then the NIPUs were modified with epoxy and cyclic carbonate-functionalized polyhedral oligomeric silsesquioxanes (POSS) to form NIPU/POSS coatings, respectively. The properties of the NIPU and NIPU/POSS coatings were determined, and the influences of POSS on mechanical and thermal properties of the resulting coatings were investigated. The results showed that by introducing POSS into the NIPU networks, the water tolerance, pencil hardness and thermal stabilities of the NIPU/POSS coatings were improved obviously with the increasing of the POSS content, but the impact strength, adhesion and flexibility of NIPU/POSS coatings were not observed to be affected to a significant extent.