Investigation of Deformation Behavior of Thiourethane Elastomers Using In Situ X-ray Scattering, Diffraction, and Absorption Methods

Tough, Recyclable, and Degradable Elastomers for Potential Biomedical Applications

Elastomers have many industrial, medical and commercial applications, however, their huge demand raises an important question of how to dispose of the out-of-service elastomers. Ideal elastomers that are concurrently tough, recyclable, and degradable are in urgent need, but their preparation remains a rigorous challenge. Herein, a polycaprolactone (PCL) based polyurethane elastomer is designed and prepared to meet this demand. Owing to the presence of dynamic coordination bond and the occurrence of strain-induced crystallization, the obtained elastomer exhibits a high toughness of ≈372 MJ m^-3 and an unprecedented fracture energy of ≈646 kJ m^-2 , which is much higher than natural rubber (≈50 MJ m^-3 for toughness and ≈10 kJ m^-2 for fracture energy). In addition, the elastomer can be recycled at least three times using solvent without losing its mechanical properties and can be degraded by lipase in ≈2 months. Finally, biological experiments demonstrate that the elastomer possesses good biocompatibility and can facilitate wound healing in mice when used as sutures. It is believed that the obtained elastomer meets the requirements for next-generation elastomers and is expected to be used in emerging fields such as biomedicine, flexible electronics, robotics and beyond.

Polyurethane elastomers with amphiphilic ABA tri-block co-polymers as the soft segments showing record-high tensile strength and simultaneously increased ductility

Polyurethane elastomers with amphiphilic ABA tri-block co-polymers as the soft segments robustly show record-high tensile strength and simultaneously increased ductility via producing small and uniform hard domains.

Precisely Alternating Copolymerization of Episulfides and Isothiocyanates: A Practical Route to Construct Sulfur-Rich Polymers

The development of a controlled and reliable method to construct well-defined sulfur-containing polymers has sparked great interest in polymer science. Herein, we present the trial on the copolymerization of isothiocyanates with episulfides in the presence of organic onium salts, which provides direct access to a class of sulfur-rich polymers. This methodology has combined advantages of simple operation, no metals, mild conditions (25-100 °C), controlled polymerization performance (M_n > 10⁵ g mol^-1, Đ < 1.3), and high reactivity (turnover frequency over 1000 h^-1). The metal-free feature and versatility of the easily accessible monomers, along with fine adjustment of the final properties enable this strategy to be a feasible approach to produce sulfur-rich polymers (16 examples).

A self-reinforcing and self-healing elastomer with high strength, unprecedented toughness and room-temperature reparability

The development of intrinsic self-healing elastomers with simultaneous high mechanical strength, toughness and room-temperature reparability remains a formidable challenge. Herein, we report a mechano-responsive strategy, known as strain induced crystallization, to address the above issue, whereby synthesized elastomers with unprecedented high mechanical performances are bestowed with room-temperature self-healing materials, achieving tensile strength, toughness and fracture energy values of 29.0 MPa, 121.8 MJ m^-3 and 104.1 kJ m^-2, respectively.