Advancing the Development of Highly-Functionalizable Glucose‑Based Polycarbonates by Tuning of the Glass Transition Temperature

Fundamental studies that gain an understanding of the tunability of physical properties of natural product-based polymers are vital for optimizing their performance in extensive applications. Variation of glass transition temperature (T_g) was studied as a function of the side chain structure and molar mass for linear poly­(glucose carbonate)­s. A remarkable range of T_g values, from 38 to 125 °C, was accomplished with six different alkyloxycarbonyl side chains. The impact of molar mass on T_g was investigated for two series of polymers and discrete oligomers synthesized and fractionated with precise control over the degrees of polymerization. The T_g was found to be greatly influenced by a synergistic effect of the flexibility and bulkiness of the repeating unit side chain, as well as the chain end relative free volume. This work represents an important advance in the development of glucose-based polycarbonates, as materials that possess high degrees of functionalizability to be capable of exhibiting diversified physicochemical and thermal properties by simple side chain modification.