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Polyurethane (PU) materials with high strength, toughness, anti‐wear properties, and high heat resistance are in high demand for dynamic sealing applications. In this study, a series of high‐performance crosslinking polyurethanes (CPUs) were prepared by pre‐polymerization of polycarbonate diol (PCDL) with toluene‐2,4‐diisocyanate (TDI), followed by crosslinking with trimethylolpropane (TMP). The molar ratio (R) of PCDL/ TDI and the degree of cross‐linking were found to significantly affect the microphase separation. The results indicate that as the R‐value increases, the transition temperature of CPUs increases from 6.0°C to 82.4°C, and the tensile strength increases from 21.1 ± 2.5 MPa to 46.0 ± 3.6 MPa. Moreover, the CPUs exhibit excellent heat resistance (with a heat resistance index of ~150°C) and hydrolysis resistance, attributed to the high crystallinity of PCDL and the synergistic effect of chemical crosslinking. Additionally, the CPUs demonstrate low friction coefficient (COF = 0.01–0.062), exceptional anti‐wear properties (Akron wear, 0.11–0.07 cm3/1.61 km), and outstanding fatigue resistance. These desirable characteristics make CPUs suitable for use as dynamic sealing or lubricating materials in harsh conditions, thereby extending the service life of seals and preventing leakage and other related issues. [ABSTRACT FROM AUTHOR]

Polymerizable deep eutectic solvent (PDES) as a newly emerging type of liquid‐free ionic conductive elastomer is considered to be the most attractive candidate for the next generation of ionotronic devices. However, it remains a huge challenge to integrate high ionic conductivity, excellent mechanical properties, good self‐healing capacity, and robust adhesion into a single material that satisfies the stringent demand of the ionotronic devices in various scenarios. Herein, a liquid‐free ionic elastomer is constructed by incorporating tannic acid‐encapsulated cellulose nanocrystals (TA@CNC) as multifunctional hydrogen bond donors (HBDs) along with poly(acrylic acid) (HBDs) and choline chloride (hydrogen bond acceptors, HBAs) to form a dynamic cross‐linking network through multiple dynamic hydrogen bonds. The presence of the rigid crystalline regions and the sufficient dynamic interaction sites on the TA@CNC endow the resultant elastomers (ACTC) with superior mechanical properties (≈496 kPa, 2400%), robust adhesion (≈68.6 kPa), and good self‐healing property. Benefiting from the above integrated features, the wearable sensors by harnessing the ACTC as a resistance sensing module is constructed that provide unaltered sensing performance under off‐axial deformation (twisting and prick). Additionally, the capacitance pressure sensor with good stability for force distribution is developed, opening up a new avenue for the development of ionotronic devices. [ABSTRACT FROM AUTHOR]

A polytetramethylene ether glycol system polyurethane elastomer that meets the TBM main drive sealing requirements was prepared. Based on the working condition of the TBM main drive seal lacking oil lubrication, the wear morphology, wear chemical changes and failure mechanism of the elastomer under different dry friction conditions are mainly explained. The results show that the hydrogen bond content and molecular structure of soft and hard segments of polyurethane elastomer will change when the friction temperature increases, leading to a decrease in mechanical properties and wear failure. With the increase of rotation speed and load, there are different temperature rise trends, wear morphologies and mechanisms, and there is an obvious sudden temperature rise before wear failure, which can be used as an important criterion for seal failure monitoring. • The three stages of change that the polyurethane elastomer material undergoes during the friction and heating process are proposed. • Revealed the influence between friction heat and working conditions parameters during the dry friction process of polyurethane elastomer. • An important criterion for the wear and failure of polyurethane elastomer materials was discovered. • The wear morphology and wear pattern of polyurethane elastomer under different dry friction conditions were explored. [ABSTRACT FROM AUTHOR]