Biomass-based, functional polyesters and polycarbonates for thermosetting coating applications

In our research, we focus on the chemistry and structure-property relations of several types of performance polymers, including thermosetting and water-borne coating systems, engineering plastics and thermoplastic elastomers. Performance polymers prepared through polycondensation are usually based on petrochemical monomers, such as bisphenol-A, neopentyl glycol and terephthalic acid. These materials need to comply with stringent requirements in terms of polymer composition, end-group functionality, processability as well as thermal, hydrolytic and UV stability. Polymers derived from biomass represent a fascinating and increasingly important field of research, as such macromolecules offer differentiated properties compared to conventional materials from fossil feedstock. [1,2] We have intensively studied aliphatic, bio-based polymers designed for thermosetting powder coating applications. [3] Powder coatings are solvent-free systems, consisting of a typically amorphous polymer resin, a curing agent and additives that are mixed by a low temperature extrusion process. Subsequently, the granules are ground into a fine powder, which is electrostatically charged and sprayed onto a metal substrate. The powder-covered substrate is then placed in an oven, where thermally induced flow and curing occur [4,5]. Therefore, the most important polymer properties are functionality, glass transition temperature, viscosity and molecular weight.