Abstract
A series of glucose-based degradable superabsorbent hydrogels with potential to tackle issues associated with sustainability, flooding, and drought has been designed and fabricated. These hydrophilic networks were constructed through integrating glucose as a primary building block -into cyclic oligomers and block polymers, which were combined into mechanically-interlocked slide-ring crosslinked materials. Crosslinking of slide ring alpha-cyclodextrin/poly(ethylene glycol)-type polyrotaxanes with acid-functionalized ABA triblock copolymers comprised of mercaptopropionic acid-functionalized poly(glucose carbonate (ethyl propargyl carbonate))-b-poly(ethylene glycol)-b-mercaptopropionic acid-functionalized poly(glucose carbonate (ethyl propargyl carbonate)), afforded degradable superabsorbent hydrogels through establishment of chemically-labile ester linkages, in addition to glycosidic and carbonate groups of the polymer precursors. With an emphasis on development of fundamental synthetic design strategies to achieve high-performance superabsorbent hydrogels that could behave as robust materials, which are derived from natural components and exhibit hydrolytic degradability, effort went into optimization of the composition, structure, and topology leading to water uptake capacities >30x by mass. Investigations of composition-structure-topology-morphology effects on properties as a function of variations of PEG main chain length, degree of alpha-cyclodextrin coverage, and concentration of pre-gel solution, indicated that the slide-ring polymer and triblock copolymer networks feature high water uptake, tunable mechanical properties, and sustainability with construction from renewable natural products and in-built degradability.