Thermally Tunable Viscoelasticity in Polyborodimethylsiloxane: A Supramolecular Approach to Dynamic Polymer Network

Polyborodimethylsiloxane (PBDMS), a supramolecular elastomer featuring dynamic Si – O – B linkages, was synthesized via condensation of hydroxyl-terminated PDMS with boric acid in a toluene medium. FTIR analysis confirmed boron incorporation, evident from a distinct absorption near 1340 cm− 1. Rheological measurements across 25–120°C revealed highly temperature-dependent viscoelastic behavior. The storage modulus (G′) decreased by nearly four orders of magnitude with increasing temperature, indicating disruption of reversible crosslinks. A two-mode generalized Maxwell model and power-law analysis captured these dynamic transitions. Compared to conventional PDMS and other supramolecular systems, PBDMS exhibited superior mechanical stability at low temperatures and gradual thermal softening. These results underscore the potential of PBDMS as a tunable, thermally responsive material for applications in adaptive damping, soft robotics, and thermal actuation, particularly where a balance of rigidity and thermal flexibility is required.