Modulating the Properties of Boronic-Based Dynamic Covalent Materials via Positional Isomerism and Tailored Functionality

Abstract

Dynamic covalent materials have received increasing attention due to their exceptional reprocessing and remolding capabilities, aligning with the requirements of a sustainable circular economy. Despite significant advancements, there remains a lack of systematic understanding regarding the influence of sophisticated molecular structures of building blocks on the thermal, mechanical, and dynamic properties of these materials. In this study, we demonstrate that the positional isomerism and tailored functionality of poly(propylene glycol) (PPG)-based building blocks exert a significant impact on the properties of boronic ester-based dynamic covalent materials. bi/tri-glucosamide-terminated PPG and ortho/meta/para-iminomethyl phenylboronic acid-terminated PPG were combined to fabricate boronic ester-cross-linked materials. Both tri-functional glucosamide and para-iminomethyl phenylboronic acid substantially enhance the glass transition temperature and the mechanical strength of the resulting materials. The dynamic properties of boronic ester give these materials solvent-assisted healing and reprocessing capabilities, allowing them to replace traditional polymer matrixes and showing broad application prospects in the field of flexible conductive materials. Our findings provide an interesting perspective on modulating the properties of dynamic covalent materials through positional isomerism and tailored functionality.