(569i) Bio-Based Thiol-Ene Polymerized Gel-Polymers: Synthesis and Properties

Polymer gels usually consist of a polymer-solvent system prepared by chemical and/or physical crosslinking. Crosslinking is commonly used in the preparation of such polymers for cosmetic, energy, medical and food applications due to the resulting high degrees of mechanical stability, thermal resistance and molding ability. Growing environmental and economic concerns as well as the uncertainty that accompanies finite petrochemical resources has resulted in an increase in research and development of bio-based polymers. Lignin, a renewable feedstock, has captured much attention due to its abundance and ability to afford useful polymer building blocks when strategically depolymerized. In order to determine if lignin could serve as a basis for bio-based monomers for polymer gels, lignin-based molecules, vanillyl alcohol (4-(hydroxymethyl)-2-methoxyphenol) and gastrodigenin (4-(hydroxymethyl)phenol), were functionalized and subsequently polymerized with multi-functional thiol monomers. The polymer properties, including thermogravimetric, thermomechanical, and mechanical properties, of the resulting thin, flexible polymers will be presented. Moreover, the swelling behavior of the films, including dependence on polymer architecture, solvent type(s), and temperature, and comparison to non-lignin-based polymers will be presented. This study adds to the list of synthesis methods of lignin-based polymers and provides insight on how to design structurally and thermally desirable bio-based gel-polymers.