Role of thiol oxidation by air in the mechanism of the self-initiated thermal thiol–ene polymerization

Abstract

We highlight the role of thiyl initiating radicals generated by air oxidation of thiols in the mechanism accounting for the self-initiation of thiol–ene polymerization. The driving force of this reaction is polarization of the S–H bond.

Thiol‐ene emulsion step polymerization in a photochemical stirred tank reactor: Molecular weight, cyclization, and fragmentation

“…The interest of using this specific couple of monomers is its long-term storage stability after mixing (Figure S3), whereas problems of spontaneous polymerization are generally encountered in thiol-ene polymerizations. 24 Premature polymerization is thus avoided without the need for additional inhibitor, which could adversely affect the extent of reaction and the polymer MW. The emulsion polymerization starts only when the 385 nm LEDs are switched on.…”

“…A typical thiol‐ene monomer macroemulsion was prepared by mixing a stoichiometric amount of DAP and DMDS (30.8%w) with an aqueous phase containing a monoacylphosphine oxide lithium salt as radical photoinitiator (TPO‐Li) and sodium dodecyl sulfate (SDS) as surfactant (Scheme 2). The interest of using this specific couple of monomers is its long‐term storage stability after mixing (Figure S3), whereas problems of spontaneous polymerization are generally encountered in thiol‐ene polymerizations 24 . Premature polymerization is thus avoided without the need for additional inhibitor, which could adversely affect the extent of reaction and the polymer MW.…”

Transition metal-free photochemical C–F activation for the preparation of difluorinated-oxindole derivatives

“…These results indicate the operational simplicity of the developed protocol, and the open-to-air conditions still lead to excellent results even though oxygen is known to oxidize thiols. 53 Preliminary studies were carried out in DMSO, and in the presence of other polar aprotic solvents, no product formation was observed. Other alternative sulfoxide and sulfone-based solvents, such as tetramethylene sulfoxide and sulfolane, did not lead to formation of the desired product (see ESI † ).…”

Study on Fire Behavior, Thermal Stability and Degradation Kinetics of Thiol-Ene with Poly(aminopropyl/phenyl)silsesquioxane

“…It can occur in the presence of oxygen and will not be affected. [ 9 , 10 , 11 , 12 , 13 ]. However, the thiol-ene polymer, like most organic polymers, is deficient in flame retardancy.…”