In this work, polymer networks are prepared by a simple cross-linked reaction of poly(vinyl butyral) (PVB) and hexamethylene diisocyanate. The cross-linked reaction was evaluated by Fourier transition infrared spectroscopy, degree of swelling and gel content. The polymer networks show high mechanical strength with tensile modulus and tensile strength over 1 GPa and 40 MPa, respectively, at rt. With PVB as switching domain, the polymer networks exhibit excellent thermal- and solvent-induced shape memory properties. Also, the influence of cross-linked density and solvents' properties on solvent-induced recovery speed were carefully investigated. Moreover, with the assistance of a shape memory effect, the polymer networks also show scratch self-healing behavior which was monitored using optical and scanning electron microscopy.

In this study, a tough shape memory polymer network based on polydopamine, poly(ε-caprolactone) and diisocyanate was synthesized in three steps. Fourier transform infrared spectroscopy was used to confirm the synthesis process. The tensile tests demonstrated the good mechanical properties of the materials with a tensile modulus and tensile strength reaching 362 and 43 MPa, respectively, at room temperature. The thermal properties of the polymer networks were investigated using differential scanning calorimetry and dynamic mechanical analysis. With two broad transition temperatures, the dual-shape memory properties were greatly affected by the deformation temperature, which was investigated in detail. Moreover, the polymers also showed good triple-shape memory and two-way shape memory effects.

Solvent-free ionic SiO ₂ nanofluids lubricant exhibited a responsive characteristic to electrical potential and triggered the formation of a nanostructured tribofilm.

This review mainly focuses on the latest development of high-strength and high-toughness polyurethanes based on supramolecular interactions, and provides a comprehensive analysis of the main types, synthetic strategies, and strengthening mechanisms.

Two-dimensional (2D) lamellar materials have unique molecular structures and mechanical properties, among which molybdenum disulfide (MoS₂) and graphitic carbon nitride (g-C₃N₄) with different interaction forces served as reinforcing phase for polytetrafluoroethylene (PTFE) composites in the present study. Thermal stability, tribological and thermomechanical properties of composites were comprehensively investigated. It was demonstrated that g-C₃N₄ improved elastic deformation resistance and thermal degradation characteristics. The addition of g-C₃N₄ significantly enhanced anti-wear performance under different loads and speeds. The results indicated that PTFE composites reinforced by g-C₃N₄ were provided with better properties because the bonding strength of g-C₃N₄ derived from hydrogen bonds (H-bonds) was stronger than that of MoS₂ with van der Waals force. Consequently, g-C₃N₄ exhibited better thermomechanical and tribological properties. The result of this work is expected to provide a new kind of functional filler for enhancing the tribological properties of polymer composites.