Degradable Thermosets Derived from an Isosorbide/Succinic Anhydride Monomer and Glycerol

Isosorbide is a renewable chemical of considerable interest as a monomer and monomer precursor due to its potential use in replacements for fossil-fuel derived polymers. In the present study, a facile microwave-assisted condensation of isosorbide with succinic anhydride was developed that dramatically reduced the reaction time. The resulting isosorbide disuccinic acid derivative (I-S-2) was polymerized under solvent-free conditions with glycerol to produce a renewable, cross-linked polyester with high modulus and appreciable thermal stability. Inclusion of 13 wt % or more of low molar mass hydroxy-telechelic poly(ethylene oxide) (PEO) (M_n = 300 g/mol) produced materials with a notable decrease in modulus and glass transition temperature. Degradation studies at 50 °C in acidic and basic solutions demonstrated the ability of the I-S-2 thermosets to be readily hydrolyzable. Furthermore, the resulting aqueous degradation solutions can be concentrated and reheated to produce new materials, albeit with a reduction in tensile properties. These I-S-2/glycerol thermosets represent economic, sustainable materials with tunable mechanical properties.