Carbon dioxide-based polyoxazolidinones (POxa) are an emerging subclass of non-isocyanate polyurethanes for high temperature applications. Current POxa with rigid linkers suffer from limited solubility that hinders synthesis and characterization. Herein, we report the addition of alkyl and alkoxy solubilizing groups to rigid spirocyclic POxa and their poly(hydroxyoxazolidinone) (PHO) precursors. The modified polymers were soluble in up to six organic solvents, enabling characterization of key properties (e.g., molar mass and polymer structure) using solution-state methods. Dehydration of PHO to POxa changed solubility from highly polar to less polar solvents and improved thermal stability by 76-102 °C. The POxa had relatively high glass transition (85-119 °C) and melting (190-238 °C) temperatures tuned by solubilizing group structure. The improved understanding of factors affecting solubility, structure-property relationships, and degradation pathways gained in this study broadens the scope of soluble POxa and enables more rational design of this promising class of materials.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Dec 27 2022|
Bibliographical noteFunding Information:
This work was supported by National Science Foundation (NSF) Center for Sustainable Polymers, which is an NSF-supported Center for Chemical Innovation (CHE-1901635) and the University of Minnesota (UMN). We thank Prof. Julia Kalow and Ian Pierce for assistance with TGA–MS data collection and Le Dung Pham for assistance with X-ray diffraction data collection. X-ray diffraction analysis was performed using a crystal diffractometer acquired through an NSF-MRI award (CHE-1229400) in the X-ray laboratory at UMN supervised by Dr. Victor G. Young, Jr. NMR analysis was supported by the Office of the Vice President of Research (OVPR), College of Science and Engineering (CSE), the Department of Chemistry at UMN, and the Office of the Director, National Institutes of Health (NIH, S10OD011952). Mass spectrometry analysis was performed at the UMN Department of Chemistry Mass Spectrometry Laboratory (MSL), supported by OVRP, CSE, and the Department of Chemistry at UMN, as well as the NSF (CHE-1336940). TGA–MS experiments made use of the IMSERC Physical Characterization facility at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633), and Northwestern University. The content of this paper is the sole responsibility of the authors and does not represent the official views of or endorsement by the NIH, MSL, or NSF.
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