Thermally Responsive Selenide‐containing Materials Based on Transalkylation of Selenonium Salts

Abstract

Covalent adaptable networks (CANs) possess unique properties as a result of their internal dynamic bonds, such as self‐healing and reprocessing abilities. In this study, we report a thermally responsive C‐Se dynamic covalent chemistry (DCC) that relies on the transalkylation exchange between selenonium salts and selenides, which undergo a fast transalkylation reaction in the absence of any catalyst. Additionally, we demonstrate the presence of a dissociative mechanism in the absence of selenide groups. After incorporation of this DCC into selenide‐containing polymer materials, it was observed that the cross‐linked networks display varying dynamic exchange rates when using different alkylation reagents, suggesting that the reprocessing capacity of selenide‐containing materials can be regulated. Also, by incorporating selenonium salts into polymer materials, we observed that the materials exhibited good healing ability at elevated temperatures as well as excellent solvent resistance at ambient temperature. This novel dynamic covalent chemistry thus provides a straightforward method for the healing and reprocessing of selenide‐containing materials.

Tailored Polyurethane Synthesis from AB-Type Monomers

“…Finally, the mechanical properties of a polyO2 film were evaluated by a tension test (Figure ). As a result, it showed fracture stress at 44 MPa with a low fracture strain value (3.3%), which was very different from conventional polyurethane elastomers known for their high toughness (fracture stress from around 0.01 to 70 MPa, strain ranges from 40 to 2800%). − ,− This significant difference would be attributed to the lower content of the soft component on polyO2 than the standard polyurethanes. Based on hard/soft segment chemistry in conventional polyurethanes, − the mechanical properties of the AB-type monomer-based polyurethane may be fine-tuned according to the intended use.…”

Aliphatic C–H Insertion Strategies Enhancing Interactions among Waste Rubbers for Recycling

“…With the increase of BDS loading, the stress–strain curve of reprocessed WR sheets approaches that of original WR sheets. Disulfide networks exhibit unique vitrimer viscoelastic properties. − The vitrimer-like behavior of reprocessable networks is researched by stress–relaxation experiments at different temperatures, establishing an Arrhenius relation between viscosity and temperature of vitrimers. − The ability to relax stresses by disulfide bonds is investigated by stress–relaxation experiments on DMA in Figure S7. The networks are effectively able to relax stresses following a single relaxation decay, and the τ ranges from about half an hour at 130 °C to a few seconds at 150 °C.…”

High-Efficiency Bactericidal and Biofilm Elimination Ability of the Biodegradable Alternating Sequence Main-Chain Polyselenium Salt

“…In the glovebox filled with nitrogen, γ -SBL (150 mg, 1 mmol) and TBAB (6.4 mg, 0.02 mmol) were first added to the ampule with a stirrer, and then BGE (130 mg, 1 mmol) was added. The reaction was conducted at 80 °C for 24 h. After polymerization, 1 mL of THF was added to dissolve the mixture, the mixture was settled in petroleum ether, the product was collected by centrifugation, and the mixture was dried to constant weight under vacuum at 40 °C . The monomer conversion was determined by 1 H NMR (CDCl 3 ), and the molecular weight and molecular weight distribution of the polymer were determined by SEC (THF).…”

“…They have many similarities. For example, both of these have oxidation− reduction properties, 35 nucleophilic reactivity, 36 and high refractive index, 37 which are used in photonic crystals, 38 selfhealing materials, 39 gold adsorption, 40 and so on. Polyselenium salts are good candidates for antibacterial applications.…”