Preparation of living and highly stable blended polyurethane emulsions for self-healing films with enhancive toughness and recyclability

Self-Healing and Reprocessable Terpene Polysiloxane-Based Poly(thiourethane-urethane) Material with Reversible Thiourethane Bonds

Polyurethane materials will come into contact with different solvents in daily life, and at the same time, they will be subject to different degrees of collision, wear and tear. Failure to take corresponding preventative or reparative measures will result in a waste of resources and an increase in costs. To this end, we prepared a novel polysiloxane with isobornyl acrylate and thiol groups as side groups, which was further used in the preparation of poly(thiourethane-urethane) materials. Thiourethane bonds generated by the click reaction of thiol groups with isocyanates endow poly(thiourethane-urethane) materials with the ability to heal and reprocess. Isobornyl acrylate with a large sterically hindered rigid ring promotes segment migration, accelerating the exchange of thiourethane bonds, which is beneficial to the recycling of materials. These results not only promote the development of terpene derivative-based polysiloxanes but also show the great potential of thiourethane as a dynamic covalent bond in the field of polymer reprocessing and healing.

Stretchable Self-Healing Plastic Polyurethane with Super-High Modulus by Local Phase-Lock Strategy

In this work, a multiblock polyurethane (PU-Im) consisting of polyether and polyurethane segments with imidazole dangling groups is demonstrated, which can further coordinate with Ni²⁺ . By controlling the ligand content and metal-ligand stoichiometry ratio, PU-Im-Ni complex with vastly different mechanical behavior can be obtained. The elastomer PU-2Im-Ni has extraordinary mechanical strength (61MPa) and excellent toughness (420 MJ m^-3 ), but the plastic PU-4Im-Ni exhibits super-high modulus (515 MPa), strength (63 MPa), and good stretchability (≈800%). The metal-ligand interaction between polyurethane segments and Ni²⁺ is proved by Raman spectra, dynamic mechanical analysis (DMA), and transmission electron microscopy (TEM). The polyurethane segments domain formed by microphase separation is dynamically "locked" by Ni²⁺ coordinated with imidazole, revealing a local phase-lock effect. The phase-locking hard domains reinforce the PU-Im-Ni complex and maintain stimuli-responsive self-healing ability, while the free polyether segments provide stretchability. Primarily, the water environment with plasticization effect serves as an effective and eco-friendly self-healing approach for PU-Im-Ni plastic. With the excellent mechanical performance, thermal/aquatic self-healing ability, and unique damping properties, the PU-Im-Ni complexes show potential applications in self-healing engineering plastic and cushion protection fields.