Chemical modification of poly(isosorbide carbonate)-based copolymers with boronic acids and the ammonolysis of the modified copolymers

Abstract

Here, the functionalization of bio-based polycarbonates by post-polymerization modification with boronic acids was demonstrated as an effective method for tuning the thermal and physical properties of original polymers without losing their original nature, i.e., the degradability into monomers and urea by ammonolysis. Poly(isosorbide carbonate)-based copolymers with hydroxy groups in the polymer main chain were modified using low-molecular-weight boronic acids and polymers containing boronic acids, respectively. The modifications significantly changed the glass transition temperature, solubility, and mechanical properties. In particular, the use of modifiers with two or more boronic acids noticeably varied the mobility of the polymer, resulting in cross-linked structures. All the modified polymers, including cross-linked polymers, were successfully degraded to monomers and urea by aqueous ammonia treatment. Thus, this study provides a design guideline to control the physical properties of PIC copolymers by balancing their stability as a polymer material and their degradability after use.