Synthesis of novel high primary hydroxyl functionality polyol from sunflower oil using thiol-yne reaction and their application in polyurethane coating

In this study, novel bio-based polyurethanes that have characteristics of both thermosets and thermoplastics were prepared. The polyol functionalized by a high number of hydroxyl groups was synthesized and its application in polyurethanes, a well-known polymer in coating industry, was investigated. Sunflower oil was decorated for the first time with propargyl groups by ring-opening of epoxied groups using boron trifluoride diethyl etherate as catalyst. The polyol is obtained by photochemical thiol-yne coupling function-alization of propargylated oil in presence of mercaptoethanol in an economical, and environmental friendly procedure. The chemical structure of this sunflower based polyol and its intermediates were determined by H-1 NMR and FT-IR analysis. A series of polyurethanes containing various NCO/OH molar ratio were synthesized by a one-step procedure. The properties of the polyurethanes were studied by performing tensile testing, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A facile and green method for the synthesis of bio-based polyurethanes and their application as a transparent coating made them exponentially advantageous. (C) 2016 Elsevier Ltd. All rights reserved.