Preparation and characterization of PDMS composites by UV-hydrosilation for outdoor polymeric insulators

Abstract

Silicone polymers are widely used as polymer insulators for housing materials due to their superior properties in the presence of wet conditions and their high electrical properties such as low dielectric permittivity. The hydrosilation reaction (that is the addition of a Si-H bond across a double bond) is used in silicone industry to form crosslinked silicone polymers. In this work silica and aluminum hydroxide were used as reinforcing fillers in order to improve the properties of the material. Investigations about the nature and the amount of reinforcing particles evidence good thermal, mechanical and electrical properties of the composites with an increase of dry arc resistance values twice higher than the unfilled system. POLYM. COMPOS., 35:1253-1262

Successful UV‐Induced RICFP of Epoxy‐Composites

“…Due to the different light guide and light source, a smaller area of the formulation surface could be irradiated. Thus, experiments with pristine formulation consisting of 1% PAG IOC8-SbF 6 and 1% thermal radical initiator TPED in BADGE were performed. It turned out that the different irradiation system in fact had a significant influence, as no reproducible and stable front was obtained.…”

“…BADGE (Sigma-Aldrich), 1,1,2,2-Tetraphenyl-1,2-ethanediol (TPED, Alfa Aesar), IOC-8 SbF 6 (ABCR), SiO 2 nanopowder (80 nm, Sigma-Aldrich), and dichloromethane (p.a., Merck) were purchased and used as received.…”

“…Subsequently, the carbon-centered radicals are oxidized to carbocations by the presence of the iodonium salt PAG (On + in Figure 1) in a RICP mechanism. The most recently developed system is based on the RTI tetraphenylethanediol (TPED, benzopinacol), the iodonium salt PAG p-(octyloxyphenyl)phenyliodonium hexafluoroantimonate (IOC-8 SbF 6 ) and the commonly used epoxy monomer bisphenol-A diglycidyl ether (BADGE) [16] (Figure 2).…”

“…The formulations for the RICFP of composite materials were prepared according to Bomze et al [17] 2 mol% IOC-8 SbF 6 and 2 mol% TPED were dissolved in the smallest possible amount of dichloromethane. The weighed amount of SiO 2 nanopowder was added to the solution.…”

“…UV-induced cationic photopolymerization of epoxy monomers has been largely used for thin-film composites fabrication. [3][4][5][6][7][8][9][10][11] The formulations are solvent free and environmental friendly, the production rate is very high and a much limited energy is required to achieve the curing process by comparison with thermal-crosslinking processes. The main limitation of UV-induced crosslinking reactions is related to the hindering of UV-light penetration toward thickness of the formulations, which limits this polymerization technique in the preparation of thick composite materials.…”