Dynamic Non-Covalent Bonds Powering Enhanced Temporary Shape Retention Temperature and Mechanical Robustness in Shape Memory Polyurethane.

Shape memory polyurethane (SMPU) with excellent mechanical properties holds significant application value in engineering. However, achieving high strength and toughness typically relies on hydrogen bonding for energy dissipation, which limits the application of such PUs due to their deformation temperature being below room temperature. Here, we introduce a rigid long-chain polyamide acid with a rich aromatic structure as a chain extender, combined with metal coordination, to develop a shape memory polyurethane with a phase transition temperature of 50 °C and outstanding mechanical performance.

Strengthening-Durable Trade-Off and Self-Healing, Recyclable Shape Memory Polyurethanes Enabled by Dynamic Boron-Urethane Bonds.

Addressing the demand for integrating strength and durability reinforcement in shape memory polyurethane (SMPU) for diverse applications remains a significant challenge. Here a series of SMPUs with ultra-high strength, self-healing and recyclability, and excellent shape memory properties through introducing dynamic boron-urethane bonds are synthesized. The introducing of boric acid (BA) to polyurethane leading to the formation of dynamic covalent bonds (DCB) boron-urethane, that confer a robust cross-linking structure on the SMPUs led to the formation of ordered stable hydrogen-bonding network within the SMPUs.

Stimuli-responsive composite particles as solid-stabilizers for effective oil harvesting.

The polymer-grafted magnetic composite particles have been synthesized and developed to harvest oil by use of their speical wettability. Different from gravity-driven oil-water separation, the prepared polymer brushes-grafted magnetic composite particles can act as solid-stabilizers that diffuse to the oil-water interfical region and effectively minimize the direct oil-water interfical area by volume exclusion, whereas the magnetic Fe3O4 core allows easy separation of Pickering emulsions from oil-water mixture under an external magnetic field. When the emulsions were heated from room temperature to 50 °C, the coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM) acts as the driving force for the destabilization of the emulsion, thereby achieving the release of oil.