Hydrosilylation Of Allyl Glycidyl Ether Research Articles

Immobilization of multifunctional silsesquioxane cage on precipitated silica supports

Synthesis of octakis({3-glycidoxypropyl}dimethylsiloxy) octasilsesquioxane (G-POSS) was carried out based on a reaction involving the hydrosilylation of allyl glycidyl ether with octakis(dimethylsiloxy) octasilsesquioxane, using Karstedt’s catalyst and toluene. SiO2/POSS hybrid systems were obtained via a method of immobilization by evaporation of the solvent, using hydrated or spherical silica obtained by precipitation in an aqueous or emulsion environment. The surface of the SiO2 was modified using octakis({3-glycidoxypropyl}dimethylsiloxy) octasilsesquioxane (G-POSS). The effectiveness of the modification of the obtained hybrid materials was verified using Fourier transform infrared spectroscopy and nuclear magnetic resonance (29Si and 13C CP MAS NMR). The tests showed that the interactions between the silica support and the modifier are of the nature of chemical adsorption. In addition a mechanism was proposed for the interactions between silica and oligosilsesquioxane. To test the final effect, the hybrid systems were subjected to morphological evaluation (transmission electron microscopy). Parameters of porous structure of the products were also determined: the specific surface area, pore diameter and pore volume. Thermal stability was tested for the pure silsesquioxane cage, the initial silica supports and the resulting systems. Elemental analysis was also carried out to determine the effect of surface modification on the degree of coverage with a particular POSS compound.

Pt/C Catalyst for Hydrosilylation of Allyl Glycidyl Ether with Trimethoxysilane

Activated carbon-supported platinum was prepared and characterized by fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), respectively. And the hydrosilylation of allyl glycidyl ether with trimethoxysilane catalyzed by platinum on activated carbon was discussed. The effects of reaction temperature, reaction time, feeding fashion and mixture ratio of precursors on the Pt/C catalytic this hydrosilylation were also investigated. The results showed that the reaction can generate the product of 3-glycidoxypropyltrimethoxysilane at an efficiency of as high as 97.4% under the optimal conditions.

Trisyl modification of epoxy- and chloromethyl-polysiloxanes

The new bulky organosilicon compound HC(Me2SiCH2CH2CH2OCH2CycloCHCH2O)3 was synthesized by hydrosilylation of tris(dimethylsilyl)methane (HMe2Si)3CH and allyl glycidyl ether (AGE) in the presence of H2PtCl6 as a catalyst. Polysiloxanes containing 3-(2,3-epoxypropoxy)propyl and chloromethylphenethyl groups were synthesized by hydrosilylation of AGE and chloromethyl styrene (CMS) with hydrogen-containing polymethylsiloxane (PMHS). Both types of polymers could be modified by incorporation of the highly sterically-demanding tris(trimethylsilyl)methyl [trisyl = (Me3Si)3C] substituent. The trisyl (Tsi) groups were attached to the obtained polymers as side chains by reacting excess trisyl lithium with benzyl chloride and epoxy groups. The epoxy groups possess a higher reactivity for TsiLi than the chloromethyl groups. The ring opening reaction between the epoxy groups and TsiLi is fast. The modification increases the rigidity of the polymers as shown by differential scanning calorimetry analysis. The incorporation of the Tsi groups into the polymer structure creates macromolecules of novel architecture with potential use as membranes for fluid separation. All the resulting polymers were characterized by FT-IR and 1H NMR spectroscopy.

Hydrosilylation of allyl glycidyl ether with triethoxysilane

Hydrosilylation of allyl glycidyl ether with triethoxysilane in presence of Speier’s catalyst leads to triethoxy(3-glycidoxypropyl)silane and triethoxy(2-glycidoxy-1-methylethyl)silane and is accompanied by isomerization of allyl glycidyl ether and cleavage of the oxirane ring and the ether bond. An effect of admixtures in allyl glycidyl ether on the process is revealed. Some other hydrosilylation catalysts and additives to Speier’s catalyst are studied

Synthesis and characterization of bis(methoxyl hydroxyl)-functionalized disiloxane and polysiloxane oligomers derivatives therefrom

With purpose to prepare waterborne polyurethane with improved performance, bis(methyoxyl hydroxyl)-functionalized polysiloxanes with different dimethylsiloxane segment length were prepared. The preparation includes three steps, the first is synthesis of 1,3-bis(glycidoxypropyl)tetramethyldisiloxane (compound I) via hydrosilylation of allylglycidyl ether with tetramethyldisiloxane, followed by a subsequent methoxylation of the resultant compound from the hydrosilylation to give 1,3-bis(3-(1-methoxy-2-hydroxypropoxy)propyl)tetramethyldisiloxane (compound II). Using this compound II and octamethylcyclotetrasiloxane (D 4), an equilibrium reaction was carried out to obtain the target Product III, i.e. bis(methoxyl hydroxyl)-functionalized polysiloxanes. The ratio of D 4/compound II was varied in order to prepare product III with different segment length consisting of dimethylsiloxane units. At each step, the outcome compounds were characterized through Infrared, 1H NMR, 13C NMR as well as H–H and H–C Correlated Spectroscopy (COSY). The results showed that each step was successfully carried out and objective products were achieved. It was estimated that compound II was not exclusive in the methoxylation step. Characterizations of the compound II enabled us to give a reliable quantitative amount for the by-products for the first time. In addition, the molecular weights of the final product III with varying dimethylsiloxane length were estimated by hydroxyl group analysis, 1H NMR and GPC, which showed a good agreement between the theoretical molecular weights and those from these tests.

Synthesis, first structures, and catalytic activity of the monomeric rhodium(I)-siloxide phosphine complexes

Four new square-plane rhodium siloxide complexes of the general formula [Rh(cod)(PR3′)(OSiR3)] (where R = Me, i-Pr, O-t-Bu, R′ = Cy, Ph) were synthesized and the structures of three of them were resolved by the X-ray method. [Rh(cod)(PCy3)(OSiMe3)] (1) appeared to be a very efficient catalyst for hydrosilylation of allyl glycidyl ether to yield, selectively, 3-glycidoxypropyltriethoxysilane, a commercially important silane coupling agent. Catalytic measurements and stoichiometric experiments of 1 with triethoxysilane suggest a mechanism where an unsaturated Rh-H species is responsible for the catalysis.Key words: rhodium (phosphine) siloxides, hydrosilylation, catalysis.

Synthesis and characterization of UV-curable polydimethylsiloxane epoxy acrylate

UV-curable polydimethylsiloxane epoxy acrylate (PSEA) was synthesized by hydrosilylation of allyl glycidyl ether with hydrogen-containing polydimethylsiloxane to give polydimethylsiloxane-type epoxy resin which modified with acrylic acid. The curing speed and the double bond conversion in the UV cured film were influenced by the purity of PSEA with Fourier transform infrared spectroscopy (FT-IR) measurements. The influences of the synthetic process, such as, the reaction temperature, the concentration of reactants and the catalyst which determined the purity and activity of resins were discussed in detail. The structures of this resin were characterized by 1H-NMR and FT-IR spectra. The molecular weight was checked by gel permeation chromatography, and M n is 45,000. The properties of the cured film were also investigated by thermogravimetric analyzer, dynamical thermal mechanical analysis, and etc. For example, tensile strength (6.9 Mpa), elongation (20%), hardness (A; 18), water absorption (24 h; 2%), weight loss (40 min, 300 °C; 5%) and etc.

Study of polysiloxanes containing epoxy groups: I. Synthesis and characterization of polysiloxanes containing 3-(2,3-epoxypropoxy)propyl groups

Polysiloxanes containing 3-(2,3-epoxypropoxy)propyl groups were synthesized by two methods, copolymerization of cyclosiloxanes by base-catalyzed equilibration and hydrosilylation of allyl glycidyl ether with hydrogen-containing silicone oils. The effects of various factors on the reactions were investigated. The structures and epoxy content of the polysiloxanes were determined by IR and 1H-NMR spectra and potentiometric titration, respectively.

Silsesquioxanes as Synthetic Platforms. 3. Photocurable, Liquid Epoxides as Inorganic/Organic Hybrid Precursors

Platinum-catalyzed hydrosilylation of allyl glycidyl ether (AGE) with octahydridosilsesquioxane ((HSiO1.5)8, T8H) and octakis(dimethylsiloxy)silsesquioxane ((HMe2SiOSiO1.5)8, Q8M8H) provides access to tetra- and octaepoxy-functionalized cubic silsesquioxanes (cubes). The resulting epoxy cubes offer “masked” silica contents of up to 65 wt %, are soluble in common solvents, and are viscous liquids at room temperature, making them attractive for coating and nanocomposite applications. They polymerize on exposure to UV light in the presence of a cationic photoinitiator to produce insoluble, hybrid nanocomposites.

Modification of silica gel with diethylamino group by novel reaction and its characterization

1,3,5,7-Tetramethylcyclotetrasiloxane (H4) was deposited on silica gel at 80°C by utilizing a chemical vapor deposition (CVD) method, where it was catalytically polymerized to form a surface coating of polymethylsiloxane (PMS). Treated silica gel (PMS-Si) increased in weight up to a plateau level, and there was no further increase with increasing reaction time. The film of PMS was partially cross linked; typical values of crosslinking ratio and film thickness were 2% and 0.6 nm, respectively. An anionic ion exchanger containing diethylamino groups was synthesized from PMS-Si by hydrosilylation of allyl glycidyl ether followed by treatment with diethylamine. Its structure was confirmed by13C and29Si CP/MAS NMR spectroscopy and FT-IR spectrophotometry. Characterization of silica gel (DEA-Si) modified with diethylamino group was evaluated by a packing of the column for liquid chromatography. As a mixture of five nucleotides was completely separated, it was recognized that DEA-Si was operated by ion exchange action. Because the surface of the silica gel was covered with hydrophobic PMS, the peak heights and retention times did not change after washing of the column with alkaline solution.

Hydrosilylation Catalyzed by Polysiloxane-Bound Platinum Complexes

Abstract A series of polysiloxane-bound platinum complexes was prepared by the reaction of chloroplatinic acid with silica-supported polysiloxane ligands containing S and -COOH (D) groups. These were tested as catalysts for the hydrosilylation of acetylene and olefins with functional groups, with the aim of synthesizing organosilicon monomers and silane coupling agents. It was found that supported platinum Catalyst A was an active catalyst for the hydrosilylation of acetylene and allyl chloride by dichloromethylsilane or trichlorosilane. By these catalytic reactions, several useful organosilicon monomers, such as dichloromethylvinylsilane and 3-chloropropyl-trichlorosilane, were obtained in good yield. Supported platinum Catalysts B, C, and D proved to be effective for the hydrosilylation of allyl glycidyl ether by trimethoxysilane to yield an important silane coupling agent, 3-glycidoxypropyltrimethoxysilane. The stability of supported Catalyst A is reported.