Fluoride-catalyzed siloxane exchange as a robust dynamic chemistry for high-performance vitrimers

Sustainable developments of new technologies require materials having advanced physical and chemical properties while maintaining reprocessability and recyclability. Vitrimers are designed for this purpose, however their dynamic covalent chemistries often have drawbacks or are limited to specialized polymers. Here we report fluoride-catalyzed siloxane exchange as an exceptionally robust chemistry for scalable production of high-performance vitrimers through industrial processing of commodity polymers such as poly(methyl methacrylate), polyethylene, and polypropylene. The siloxane-based vitrimers show significantly enhanced creep resistance compared to their linear polymer precursors while maintain excellent flow at high shear rates and elevated temperatures. As a result, the siloxane-based vitrimers can be reprocessed and recycled multiple times without degradation of mechanical properties. In addition, the siloxane-based vitrimers show improved resistance to heat, oxidation, and hydrolysis. Furthermore, the siloxane exchange between different vitrimers during mechanical blending result in self-compatibilized blends without any compatibilizers. This offers a general, scalable method for producing sustainable high-performance vitrimers and a new strategy for recycling mixed plastic wastes.