Photo‐Induced Cross‐Linking of Divinyl Ethers by Using Diphenyliodonium Salts With Highly Nucleophilic Counter Anions in the Presence of Zinc Halides

Abstract

This study describes the use of diphenyliodonium salts with highly nucleophilic counter anions to photoinitiate the cationic cross‐linking of divinyl ethers. Both direct and indirect initiating modes are used. In the direct acting system, only a diphenyliodonium salt with a highly nucleophilic counter anion and a zinc halide are employed as initiator and activator, respectively. In the indirect systems, in addition to direct system components, photosensitive additives such as anthrecene, perylene, 2,2‐dimethoxy‐2‐phenyl acetophenone, benzophenone, and thioxanthone, which absorb the energy of the incident light and activate the iodonium salt, are used to initiate polymerization. All systems employed in this study initiated quite vigorous polymerizations.magnified image

Epoxy silsesquioxane resists for UV nanoimprint lithography

“…Kahveci et al 6 demonstrated a three step mechanism of initiation of the polymerization: in the first step the sensitizer absorbs the irradiation, creating an excited state and a radical specie is formed, in the second step an electron is transferred from the sensitizer to the photoinitiator leading to its dissociation and finally a Brönsted acid is generated by a proton release and the neutral form of the sensitizer is recovered. Once the acid is generated, it can attack an epoxy ring and thus initiates the polymerization.…”

Synthesis of Poly(isobutyl vinyl ether)-graft-Poly(ethylene oxide) Co-polymer with Pendant Methacrylate Functionality and Its Photo-curing Behavior

“…The details of synthesis and characterization have been reported in a previous paper [21]. In the present study, the backbone was designed as a random co-polymer of IBVE and VE-PEO-MA, and prepared by the photoinitiated living cationic polymerization [24][25][26][27][28][29]. The polymerization consists of two steps; (i) photoinduced adduct formation and (ii) subsequent propagation with activated by the coordinating effect of zinc iodide.…”

“…tions. However, such chain-breaking reactions are minimized when the photopolymerization is performed in the presence of onium salt with nucleophilic counter anion and a Lewis acid such as ZnI 2 [27,28,30]. The chemical structure of the graft co-polymer obtained was confirmed by both 1 H-NMR and FT-IR spectroscopy.…”

Photoinitiated Cationic Polymerization: Reactivity and Mechanistic Aspects

“…Recently, photoinduced living cationic polymerization of isobutyl vinyl ether (IBVE) in the presence of various diphenyliodonium salts and zinc halides was CHART 11.17 reported by Mah and coworkers [9][10][11][12]. Photochemically generated protonic acid reacts with IBVE to form the corresponding monomer adduct.…”