Biobased and Biodegradable Polycondensates

Plastics are indispensable in today’s society due to their affordability, versatility, durability, and ease of shaping and processing. However, most conventional plastics are derived from fossil resources, are not biodegradable, and only a small fraction is properly recycled. This leads to the accumulation of plastic waste in the environment and contributes to the growing problem of microplastics. This thesis presents fundamental investigations and applied polymer research aimed at advancing the development of new biobased and biodegradable materials. The sugar-derived monomers 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) were enzymatically polymerized with various comonomers to investigate the structure-property relationship. For the first time, (co)polyesters based on BHMF and BHMTHF were demonstrated to be biodegradable, opening new opportunities for designing degradable aromatic-like polyesters. The thermal and mechanical properties of BHMF-based polyesters were enhanced by converting them into covalent adaptable networks. Thermoreversible materials were synthesized by reacting various BHMTHF-based polyesters with an aliphatic bismaleimide, based on Diels-Alder chemistry. Furthermore, natural polyols, such as xylitol, were used as crosslinkers to obtain mechanically recyclable vitrimers. The applied polymer research included the synthesis, analysis, and upscaling op polyester amides. The commercially available biobased monomers butanediol, BHMTHF, adipic acid, and the nylon 6,6 salt were used to prepare a library of biodegradable polyester amides with tunable properties. The insights presented in this thesis support the development of biobased and biodegradable polymers as sustainable alternatives to fossil-based, non-biodegradable materials, highlighting their versatility, tunability, and applicability across a wide range of future applications, such as fibers, coatings and high-performance materials.