Naturally-Derived Sustainable Hydrogel Materials Based on Slide-Ring and Triblock Copolymer Topologies

Slide-ring materials, which are derivatives of polyrotaxanes, are composed of linear polymer guest chains threaded into multiple cyclic molecular hosts that are interconnected to form mechanically-interlocked polymer complexes. The mobility of the host rings along the polymer guest chains makes these specialized polyrotaxanes promising materials in hydrogels, in comparison to energy-dissipating gels that are often difficult to recover to the original state immediately during loading processes. Inspired by previous studies, we developed a series of hydrogels based on slide-ring materials and potentially degradable triblock copolymers. The target hydrogels were synthesized with polyrotaxanes prepared from poly(ethylene glycol)s (PEG) with (2-hydroxypropyl)-α-cyclodextrins (HP-α-CDs) threaded and triblock copolymers incorporating carboxylic acid-modified poly(d-glucose carbonate) and PEG chain segments. The polyrotaxanes and triblock copolymers were then crosslinked through esterification reactions. This presentation will discuss results from investigations of composition-structure-topology-morphology effects on the properties as a function of the polymer parameters, including variation of the PEG main chain length, degree of coverage of α-cyclodextrin, poly(d-glucose carbonate) length, and the concentration of pre-gel solution.<br/>The resulting slide-ring polymer and triblock copolymer networks are expected to contain the following features:<br/>1. High water uptake ability<br/>2. High mechanical properties to help change its volume and retain its structure after water absorption<br/>3. Sustainability with the construction from renewable natural products and in-built degradability