Yinlei Lin

The limited self‐healing capability of materials synthesized using conventional isocyanate‐based microcapsules as repair agents highlights the need for innovative microcapsule systems. In this study, a novel microcapsule (PU1) design is introduced that incorporates dynamic disulfide bonds, endowing the microcapsule walls with self‐healing properties. Additionally, a comparative analysis is performed with conventional microcapsules (PU2) synthesized using 1, 4‐butanediol. The prepared PU1 microcapsules exhibited a typical shell‐core structure, and the median particle size decreased with increasing stirring speed. The glass transition temperature (T_g) of the prepared PU1 microcapsule is −53.2 °C, while that of the PU2 microcapsules is −45.0 °C. Moreover, after being placed at 60 °C for 24 h, the damaged PU1 microcapsules effectively self‐healed. In contrast, the PU2 microcapsules do not demonstrate significant self‐healing properties. Furthermore, elastomer films with the same chemical composition are prepared, and the tensile strength and the elongation at break of the PU1 elastomer are 7.3 MPa and 1450%, respectively, demonstrating excellent mechanical properties. This work provides a novel approach for preparing intrinsic self‐healing polyurethane microcapsules, which is expected to solve the issue of non‐repetitive healing in external self‐healing materials.

Tissue adhesives are increasingly sought after for their potential to minimize invasiveness, simplify surgical procedures, and reduce operative times; however, conventional polyacrylamide (PAM)-based hydrogels are often hindered by irreversible bonding, which limits their reusability and compromises both mechanical integrity and self-healing ability. Motivated by the natural adhesion mechanisms of mussels, we have developed an innovative tissue adhesive hydrogel by incorporating polydopamine (PDA) and cysteine (Cys) into a PAM matrix via free radical polymerization, with polyethylene glycol diacrylate (PEGDA) serving as an effective cross-linker. In our system, PDA contributes essential catechol groups for strong tissue adhesion, while Cys not only preserves these groups from oxidation but also enhances hydrophilic interactions, resulting in a PDA-Cys-PAM hydrogel with a tensile strength of 23.4-30.7 kPa, a fracture elongation of 628-706%, and an elongation recovery of 48%. Significantly, the seamless integration of nanoclay into the hydrogel network further reinforces its structure and improves energy dissipation, leading to a marked enhancement of the self-healing performance─evidenced by an increase in the elongation recovery rate to 71.9%─without compromising the inherent mechanical properties. Moreover, in vitro assays with NIH3T3 cells demonstrate excellent biocompatibility, underscoring the potential of this synergistic design. Overall, our work not only elucidates the distinct and cooperative roles of PDA, Cys, and nanoclay but also represents a significant advancement in the design of reusable, high-performance tissue adhesives for potential applications in tissue repair and regeneration.

Single‐component wet‐curing polyurethane (SPU) coatings offer high curing efficiency; however, their practical application is hampered by suboptimal appearance, mechanical shortcomings, and limited thermal stability. To overcome these limitations, we synthesized novel biooxazolidines—HDI‐IHO and MDI‐IHO—via the reaction of 2‐isopropyl‐3‐hydroxyethyl‐1,3‐oxazolidine (IHO) with hexamethylene diisocyanate (HDI) and 4,4′‐diphenylmethane diisocyanate (MDI), respectively. When incorporated into the SPU matrix, these biooxazolidines effectively mitigate surface defects, such as bubbles and pinholes, thereby significantly enhancing coating smoothness and overall appearance. Moreover, the introduction of these latent curing agents not only improves the thermal stability of the cured system but also substantially boosts its mechanical properties, as evidenced by increased tensile strength and elongation at break. An optimal biooxazolidine mass fraction of 8% was determined, yielding the best mechanical performance. In addition, the modified SPU exhibits remarkable self‐healing capabilities, with visible repair of coating cracks achieved at 60°C.

The reutilization non-metallic components from a waste-printed circuit board (WPCB) has become one of the most significant bottlenecks in the comprehensive reuse of electronic wastes due to its low value and complex compositions, and it has received great attention from scientific and industrial researchers. To effectively address the environmental pollution caused by inappropriate recycling methods, such as incineration and landfill, extensive efforts have been dedicated to achieving the high value-added reutilization of WPCB non-metals in sustainable polymer composites. In this review, recent progress in developing sustainable polymer composites based on WPCB non-metallic components was systematically summarized. It has been demonstrated that the WPCB non-metals can serve as a promising reinforcing and functional fillers to significantly ameliorate some of the physical and chemical properties of polymer composites, such as excellent mechanical properties, enhanced thermal stability, and flame retardancy. The recovery strategies and composition of WPCB non-metals were also briefly discussed. Finally, the future potentials and remaining challenges regarding the reutilization of WPCB non-metallic components are outlined. This work provides readers with a comprehensive understanding of the preparation, structure, and properties of the polymer composites based on WPCB non-metals, providing significant insights regarding the high value-added reutilization of WPCB non-metals of electronic wastes.

While it is challenging to simultaneously achieve both high mechanical performance and self-healing ability within one polymer hydrogel network, we, herein, synthesized a novel class of hydrogels based on a combination of chemical and dual non-covalent crosslinks via micellar polymerization of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, end-capped by 2-hydroxyethyl methacrylate (IPDI-HEMA), with acrylamide (AM). The prepared hydrogels were demonstrated to possess a tensile elongation at a break of at least 1900%, a fracture energy of 138.4 kJ m⁻³, and remarkable self-healing behaviors (e.g., a strong self-healing ability achieved at ambient temperature without the need for any stimulus or healing agent). The multiple crosslinks developed in this study for one polymer hydrogel network are significant steps to construct the desired functional hydrogels with excellent self-healing and mechanical properties.