Sustainable Polymer Synthesis and Degradation
Polymer based materials are an essential part of our daily life. With an ever increasing demand for these materials, tackling critical issues such as energy use, environmental pollution, and climate change is essential in the context of materials production and application. In this seminar, I will present our recent efforts to address these problems from the viewpoints of both polymer synthesis and end-of-life degradation. In a typical ring-opening metathesis polymerization (ROMP), the catalyst is always covalently bound to the end of the growing polymer chain. Therefore, each catalyst can only form one polymer chain, which dictates that stoichiometric amounts of the transition metal complex are required. This results in high catalyst loadings, especially during the synthesis of low molecular weight polymers, which is expensive and leads to potentially toxic transition metal residues in these polymers. We recently developed a catalytic ROMP method and a catalytic living ROMP method. These two newly developed synthetic methods significantly decrease the catalyst loading, enabling an inexpensive and environmentally friendly approach for the future development of ROMP. To address the end-of-life of polymer materials, we recently introduced a method for incorporating a cyclobutane mechanophore into polymer backbones by radical polymerization that facilitates on-demand polymer degradation through mechanical activation, while maintaining similar materials properties to the unmodified homopolymers.