Abstract:

This thesis presents the implementation of organoalkoxysilanes in commodity plastics to achieve dynamic covalent exchange chemistries for sustainable polymer design. By leveraging an innovative fluoride-catalyzed siloxane exchange, we demonstrate the production of robust, high-performance vitrimers. We report that dynamic crosslinking within vitrimers causes a “self-compatibilization” process that offers a facile method to access homogeneous polymer blends. We expand upon this work by developing a general method of compatibilizing commodity polymers using aromatic sulfonyl azide crosslinkers to install the dynamic siloxane crosslinks. When heated to relevant polymer processing temperatures, these aromatic sulfonyl azides decompose to singlet nitrenes capable of direct C–H insertion, thereby crosslinking numerous polymers, or even the blends of polar and nonpolar plastics. Simulated mixed plastic waste was compatibilized using a small amount the crosslinker, enhancing mechanical performance and improving interfacial adhesion. These efforts constitute new strategies to address the challenges of plastic recycling to advance toward a more sustainable future.