Synthesis and characterization of ladder-like phenylene-bridged polysiloxanes

Silicone‐Based Organic–Inorganic Hybrid Aerogels and Xerogels

“…This viscoelastic behavior of stress relaxation may be ascribed to enhanced plasticity of the EBPMS network, due to the lower cross‐linking density and possibly due to an increasing fraction of linear chains. This speculation is supported by the fact that ladder‐like polyorganosiloxane chain polymers are synthesized from bis(organodialkoxysilyl) monomers with organo‐bridging groups The viscoelastic behavior is further confirmed by intermittent bending tests on the EBPMS aerogel as shown in Figure c. While the testing crosshead stops for 300 s at each arrowed point with keeping constant strains, the EBPMS aerogel shows apparent decreases in bending stress, while PMSQ aerogels show little stress relaxation.…”

Surface modified ormosil nanoparticles

“…A strong peak at 1079 cm −1 has been assigned to Si-O-Si stretch, while the peaks at 1104 and 1081 cm −1 , Scheme 1. which are assigned to Si-O-C in monomer vinyl triethoxysilane (VTES), shown in Fig. 2a, are absent in the nanoparticles [8,9,21]. These peaks of Si-O-C vibrations in VTES disappear due to the hydrolysis of the ethoxy groups, and a single 1079 cm −1 peak of Si-O-Si emerges.…”

Synthesis of Silphenylene-Containing Siloxane Resins Exhibiting Strong Hydrophobicity and High Water Vapor Barriers

“…As shown in Figure 1, the spectra of trimethoxyphenylsilane, BDMPD, and VPSSP clearly exhibited three key absorptions. More specifically, the signal at 1139 cm −1 was attributed to the Si-C 6 H 4 -Si group [22,23], while the weak signal at 3149 cm −1 originated from vibrations of the phenylene C-H moieties [21], and the signals at 1000-650 cm −1 corresponded to the aromatic C-H deformation vibration region, where a new signal and a shift in the signal (emphasized by colored bands) were observed. This was likely due to the difficulty in accurately controlling the Grignard reaction during synthesis, and so small amounts of silicon monomers containing more than one phenylene unit were simultaneously formed.…”