Hyperbranched polyurethane (HBPU)-urea and HBPU-imide coatings: Effect of chain extender and NCO/OH ratio on their properties

► In this study a series of HBPU-urea and HBPU-imide coatings were synthesized. ► The effects on coating properties were studied by varying the type of chain extender and NCO/OH ratio. ► Structure-property correlation of the coatings based on hydrogen bonding interaction was investigated by FTIR peak deconvolution. ► PMDA based coating possesses highest thermal stability and Tg value. ► Thermal, viscoelastic and other coating properties all increase with increasing the NCO/OH ratio.