Synthesis of Organic−Inorganic Hybrid Gels from Siloxane or Silsesquioxane and α,ω-Nonconjugated Dienes by Means of a Photo Hydrosilylation Reaction

Abstract

Organic−inorganic hybrid gels have been synthesized from the multifunctional cyclic siloxane, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), or the cubic silsesquioxane, 1,3,5,7,9,11,13,15-octakis(dimethylsilyloxy)pentacyclo-[9,5,1,1,1,1]octasilsesquioxane (POSS), as cross-linking reagents with α,ω-nonconjugated dienes, 1,5-hexadiene (HD) or 1,9-decadiene (DD), using a photo hydrosilylation reaction with a bis(acetylacetonato)platinum catalyst in toluene. Network structures of the resulting gels, mesh size, and mesh size distribution were quantitatively characterized by means of a novel scanning microscopic light scattering (SMILS). The effects of the monomer concentration in the resulting gels were investigated, and gels with homogeneous network structure formed by 1.4 to 1.6 nm size of mesh were obtained under the monomer concentrations that are relatively higher than the critical gelation concentration. The mesh sizes of gels, that were determined with SMILS, with DD were larger than those with HD and were independent of the nature of the cross-linking reagents. The TMCTS-HD gel formation process was successfully traced with SMILS. The result indicates the formation of microgels in the early stages of the reaction following aggregation of the microgels, extension of the microgels, or both to form the infinite network that occupies the space of the reaction system around the gelation point. Photo-pattern coating of a glass plate with the POSS-DD gel was achieved by means of the photo hydrosilylation reaction of the cast reaction medium.

Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing

“…Previously, many works have been devoted to develop IL‐based gel materials by using a variety of materials and methods with detailed investigation of mechanical, thermal, conductive, and electrolytic properties . Our research group has also established a wide variety of end‐crosslinked polymer gels and those expertise has been associated with IL in this work to create new functional materials . Use of IL in end‐crosslinked type thiol–ene polymerization has been out of focus and only very early stage reaction mechanism, kinetics, and information about their interaction are reported preliminarily .…”

“…[3,[8][9][10] Our research group has also established a wide variety of end-crosslinked poly mer gels and those expertise has been associated with IL in this work to create new functional materials. [11][12][13][14] Use of IL in end-crosslinked type thiolene polymerization has been out of focus and only very early stage reaction mechanism, kinetics, and information about their interaction are reported preliminarily. [15,16] Very recently, some researchers have used crosslinkable ILs with multifunctional thiol end-crosslinkers to develop polyionic liquids (PIL) by following the mechanism of thiol-ene reaction.…”

Effect of crosslink density on the refractive index of a polysiloxane network based on 2,4,6,8‐tetramethyl‐2,4,6, 8‐tetravinylcyclotetrasiloxane

“…Hydrosilylation is an important addition reaction, which involves the formation of a new bond between the vinyl group and the Si–H bond . Several studies have been performed to affect a crosslinked network utilizing D 4 V and silsesquioxane via a hydrosilylation reaction in either organic–inorganic systems or wholly inorganic systems . Most of these works studied the thermal and oxidative stability and gel formation of the network.…”

Synthesis and optical properties of organic-inorganic hybrid semi-interpenetrating polymer network gels containing polyfluorenes

“…The authors recently developed organo‐chemical gels composed by organic–inorganic hybrid network in organic solvents. The organic–inorganic hybrid gels were synthesized by a hydrosilylation reaction of multiple Si‐H functional cyclic siloxane, 1,3,5,7‐tetramethylcyclotetrasiloxane (TMCTS) or cubic silsesquioxane 1,3,5,7,9,11,13,15‐octakis(dimethylsilyloxy)pentacyclo‐[9,5,1,1,1,1]octasilsesquioxane (POSS) with α,ω‐nonconjugated dienes, 1,5‐hexadiene (HD), and 1,9‐decadiene (DD) in toluene . The gels are composed by geometrical multifunctional joint molecules and bifunctional rod molecules.…”

“…The SMILS analysis of the gels cleared the extremely narrow distribution of mesh size in the gels. Furthermore, the mesh size of the gels could be controlled by the length of the α,ω‐nonconjugated dienes used, and the gels composed of long spacer monomer of DD or cubic crosslinking reagent of POSS containing formed large mesh size, about 1.5 nm, in the network structure …”