Efficient initiation of radical‐mediated thiol‐ene chemistry with photoactive silica particles

Abstract

This work aims at the design of photoactive inorganic filler by covalently attaching tri(methoxy)silyl‐functionalized bis(acyl)phosphane oxides (TEMSI2‐BAPO) onto silica particles. The immobilization of the photoactive groups is evidenced by spectroscopic measurements and thermal gravimetric analysis. The modified particles are then incorporated into thiol–ene resins to study the efficiency of the Norrish type I photofragmentation reaction of the covalently bound TEMSI2‐BAPO derivatives. The photopolymerization kinetics of the thiol–ene system is monitored by FT‐IR spectroscopy and photo‐DSC upon prolonged exposure with UV‐light and compared with the results achieved with IRGACURE 819 (free BAPO). Rapid curing and high conversion yields are obtained evidencing the high efficiency of the photoactive particles. In addition, negative‐toned patterns are inscribed in thin thiol–ene films by photolithographic processes and characterized by microscopic techniques demonstrating the versatile applicability of the photoactive particles. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 894–902

Surface-Immobilized Photoinitiators for Light Induced Polymerization and Coupling Reactions

“…Regarding bis(acyl)phosphane oxide (BAPO) modified surfaces, the higher reactive radical remained on the surface since the phosphinoyl radical was about 1000 times more reactive than the acyl one [ 34 ]. In addition, BAPO derivatives are frequently used because they are able to form more than one radical upon UV irradiation, have an extended absorption window (λ = 360–440 nm) and show rapid photobleaching which enables deeper light penetration [ 35 ].…”

“…Nevertheless, it was proven that photoactive nanoparticles were capable of polymerizing acrylic monomers (e.g., tetrahydrofurfuryl acrylate) and thiol-ene resins [ 31 ]. As an approach towards low extractable photoinitiators, Sahin [ 35 ] investigated silica nanoparticles bearing BAPO initiators ( Figure 5 D) at their surface with respect to the initiation of thiol-ene photopolymerization. Migration of the filler bound photoinitiators was examined by extraction of thiol-ene photopolymers.…”

Polyethylene Nanocomposites for Power Cable Insulations

“…Besides the dispersibility, the particle-polymer interfaces can be tailored by incorporating functional groups on the fillers’ surfaces. As the particle-polymer interface has a crucial influence on the performance of the corresponding nanocomposites, surface modification techniques have gained increased attention for tuning the mechanical and electrical performance of polymer nanocomposites [76,77,78,79]. Pallon et al [80] applied functional silsesquioxane coatings on MgO nanoparticles and incorporated the functional filler in LDPE.…”

The synthesis and characterization of polyorganosiloxane nanoparticles from 3-mercaptopropyltrimethoxysilane for preparation of nanocomposite films via photoinitiated thiol-ene polymerization

“…This article presents the synthesis of polyorganosiloxane nanoparticles with (3-mercaptopropyl) trimethoxysilane (MPTMS) and the preparation of nanocomposite films with these nanoparticles via the photoinitiated thiol-ene polymerization reaction. Although there are very few articles reported on the application of silica nanoparticles in photopolymerized thiol-ene systems up to date, not enough attention is paid to this field [30,31]. In the literature, Chen et al studied UV curing photopolymerization of thiol-ene acrylates with commercial silica nanoparticles and investigated the thermal stability and chemical resistance of the resulting products [32].…”