UV-mediated Thiol-ene Polyol Functionalization for Synthesis of Biobased Waterborne Polyurethanes

Abstract

This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Abstract Developing waterborne polyurethane coatings from biobased polyols represents an interesting alternative, allowing at the same time to increase the use of sustainable renewable raw materials and to reduce volatile organic compounds emissions. In this work, biobased Veopur polyol was first functionalized with mercaptopropionic acid using solvent-free UV-mediated thiol-ene reaction performed in bulk. Grafted carboxylic moieties were then neutralized by triethylamine in order to obtain the required amphiphilic behavior. In the final step, functionalized water dispersible polyol was polymerized with water soluble polyisocyanate to form waterborne polyurethane (WPU). The influence of key-process parameters on grafting efficiency was investigated by iodometric titration, Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance. Particle size measurements and stress-strain tests were carried out to characterize WPU water dispersions and corresponding materials, respectively.