Thermal, Near-Infrared Light, and Amine Solvent Triple-Responsive Recyclable Imine-Type Vitrimer: Shape Memory, Accelerated Photohealing/Welding, and Destructing Behaviors

Abstract

Currently, polyimine vitrimer is restricted by unitary functionality and poor responsiveness to external stimuli, thus showing limited potentials for broader applications as a kind of smart material. Herein, we reported a thermal, near-infrared light, and amine solvent triple-responsive polyimine vitrimer (ACAT-vitrimer) by incorporating oligoaniline into a traditional imine-type vitrimer through the polycondensation reaction of terephthaldehyde, m-xylylene diamine, and tris (2-aminoethyl) amine. The material exhibited superior mechanical properties, thermal stability, rheology, welding property, and recyclability. More interestingly, the ACAT vitrimer also demonstrated a unique photothermal conversion property. Compared with traditional hot-pressing method, the photoinduced shape memory behavior of the ACAT-vitrimer was much more controllable and efficient. Additionally, the ACATvitrimer exhibited accelerated photohealing/welding and complete destructing behaviors under the irradiation of near-infrared (NIR) light, which was reported for the first time as a kind of imine-based vitrimer. Such easy fabrication strategy combining dynamic covalent chemistry with a spatiotemporally controllable photothermal effect provided an efficient approach to convert the conventional imine-type vitrimer into stimulus-responsive materials for broader applications.

Solvent Responsive Shape Memory Polymers‐ Evolution, Current Status, and Future Outlook

“…The shape memory polymer market size is currently valued at USD 392.4 million, and it is predicted to show a compound annual growth rate of 21.5% from 2021 to 2027. [128,129] With the increase in the demand for the commercialized product that needs shape morphing, the research and development of the novel shape memory polymers shall be a game-changer, transforming the current shape memory realm.…”

Linear and star-shaped π-conjugated oligoanilines: a review on molecular design in syntheses and properties

“…233 The syntheses of vitrimers containing oligoanilines resulted in significant progress towards the fabrication of multi-stimuli-responsive materials. [234][235][236] The neat vitrimer responds to heating, while the addition of the oligoaniline to the system as a monomer results in the formation of the multi-stimuli-responsive vitrimers. Apart from the multi-responsivity and multifunctionality, such as shape memory, healing, and welding, some of the final properties are emergent and have not been inherited from each component, for instance, photohealability, photoweldability, and pH-induced shape memory.…”

“…The balance between those delineates the optimum amount of solvent for the desired healing/welding processes. 236 The oligoanilines' ability to absorb solar light and efficiently convert light into heat has been exploited to prepare wellperforming organic self-floating evaporators for solar cells. 237 Chen et al engineered an efficient evaporator (80% efficiency at 0.5 sun) with high thermal stability (300 °C) and a hydrophobic surface (contact angle of 130°) (Fig.…”

“…234 Triple-responsive polyimine-trianiline vitrimers can show photohealing/welding under the irradiation of near-infrared (NIR) light. 236 By an increase in the amine-capped trianiline (ACAT) monomer in the synthesis of poly imine vitrimer, the tensile modulus, strength and the elongation at breaks increases, and T g of the polyimine-ACAT shifts from 100 °C to 107 °C. The ACAT-polyimine has revealed thermo- and photoinduced shape memory behavior (Fig.…”

“…The balance between those delineates the optimum amount of solvent for the desired healing/welding processes. 236…”