Electromechanically Durable Graphene Oxide-Embedded Elastomer via Simultaneous Corporation of Siloxane/Polyol Based on the Dual Secondary Bond Architecture

Graphene, an electrically conductive reinforcement material, is investigated for its strain sensing capabilities in the form of a thermoplastic polyurethane–graphene oxide (TPU–GO) composite. The electromechanical properties of the graphene-based strain sensors at different loading concentrations of 3, 5, and 7 wt % GO were studied. The TPU–GO strain sensor with the 7 wt % GO loading concentration was found to endow the most sensitive and stable electromechanical performance. The TPU–GO strain sensor was better with the addition of polyethylene glycol (PEG) (TPU–GO–PEG), which behaves as a binder, and was further enhanced with the formation of a hybrid silica structure (SiO 2 ) (TPU–GO–SiO 2 ) in the polymer matrix. Its strain sensing performance was further examined in terms of stretch–release cycles at different strains, durabilities, and strain speeds. Notably, the TPU–GO–PEG–SiO 2 strain sensor exhibited the highest gauge factor (GF = 9.14); significantly enhanced mechanical properties, thermal stability, and electrical response; and long-term durability (>20,000 cycles). This is attributed to the homogeneous dispersion of GO sheets and a strong interfacing interaction between the conductive filler and the TPU matrix aided by siloxane and polyether via hydrogen bonds.