Synthesis and properties of POSS-containing gallic acid-based non-isocyanate polyurethanes coatings

Abstract A series of novel biomass-based nonisocyanate polyurethanes (NIPUs) coatings were successfully prepared via the reactions of gallic acid-based cyclic carbonate with diamines. Then the NIPUs were modified with epoxy-functionalized POSS to form NIPU/POSS coatings with chemically linked POSS groups. The properties of the NIPUs and NIPU/POSSs were determined, and the influences of POSS on mechanical and thermal properties of the resulting coatings were investigated. The results showed that the gallic acid-based NIPU coatings have excellent impact strength, adhesion, flexibility, pencil hardness and thermal stability, but suffering from low water resistance. By introducing POSS into the NIPU networks, the pencil hardness, water resistance and thermal stability of the NIPU/POSS coatings were improved, while the adhesion of the coatings were observed to be slightly decreased.