• Journal of the Korean Chemical Society
• /
• v.40 no.9
• /
• pp.635-639
• /
• 1996

New bis-crown ether containing siloxane chain was synthesized. 1,3-Bis(trimethylsiloxy)-1,3-dimethyl-1,3-di(4'-ethylbenzo-18-crown-6) disiloxane (1) was synthesized by reaction of 4'-vinylbenzo-18-crown-6 with 1,3-bis(trimethylsiloxy)-1,3-dimethyl-1,3-disiloxane in the presence of Pt catalyst. 4'-Vinylbenzo-18-crown-6 was prepared through five-step reaction which started from the reaction of catechol and acetic anhydride.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.57-62
• /
• 2005

The potentiometric responses for various anions are investigated with membrane electrode (membrane 1) based on 1,3-diethyl-1,3-dihydroxy-1,3-bis(2-dimethylaminomethyl ferrocenyl) disiloxane. The nitrate ion-selective electrode based on compound 1 gave a good Nernstian response of 58.18 mV per decade for nitrate with the detection limit of −e5.66 of log [NO3−e]. Compound 1 has all those functional groups and the other two compounds have less functional group of ferrocenyl or ferrocenyl and hydroxide, respectively. Even though, potentiometric response to anions was excellent at pH 5, the selectivity pattern for all three membrane electrode based on series of disiloxane is almost like Hofmeister sequence at pH 5. However, the membrane electrode 1-3 exhibited very different response to anions at pH 7. In this pH, NH2 is not protonated and ionophore may act as neutral carrier. Hydrogen bond may enhance the responsibility to hydrogen acceptors and intramolecular electro-active site may increase the permeability of analyte to ionophore in membrane.

• Journal of the Korean Chemical Society
• /
• v.38 no.5
• /
• pp.377-381
• /
• 1994

New bis-crown ethers containing siloxane chain were synthesized. 1,3-Bis(trimethylsiloxy)-1,3-dimethyl-1,3-dipentaoxacyclohexadecamethyl disiloxane (1) was synthesized by reaction of 3-methylene-16-crown-5 (8) with 1,3-bis(trimethylsiloxy)-1,3-dimethyl disiloxane (10) in the presence of Pt catalyst. 1,1,3,3,5,5-Hexamethyl-1,5-dipentaoxacyclohexadecamethyl trisiloxane (2) was synthesized by the reaction of crown ether (8) with 1,1,3,3,5,5-hexamethyl trisiloxane (11) in the presence of Pt catalyst. 3-Methylene-13-crown-4 (7), 3-methylene-16-crown-5 (8), and 3-methylene-19-crown-6 (9) were synthesized by the reaction of triethylene glycol (3), tetraethylene glycol (4), and pentaethylene glycol (5) respectively with 3-chloro-2-chloro-methyl-1-propene (6) in the presence of NaH.

• Composites Research
• /
• v.26 no.3
• /
• pp.170-174
• /
• 2013

Atmospheric glow plasma polymerization was applied to wood powder before fabricating polypropylene (PP) matrix composites. Seven different types of monomers (Oxygen, Benzene, CH4, Acrylic-acid, Hexafluoroethane, Trifluorotolune, Hexamethyl-disiloxane) were analyzed to determine the most suitable precursor for plasma polymerization. The surface energy was calculated from measured contact angle about each monomer on PP. Hexamethyl-disiloxane (HMDSO) had a highest surface energy and is selected as the most suitable monomer. Wood powder and polypropylene were mixed as pellets by twin screw extruder and then 50 wt% wood powder/PP composites were produced by an injection machine. Tensile strength and Flexural strength have improved by 7.59% and 12.43% at the maximum respectively. SEM (Scanning Electron Microscope) observation on the fracture surface revealed that the plasma polymerization have improved the interfacial bonding and the mechanical properties of the composites.

• Applied Chemistry for Engineering
• /
• v.18 no.2
• /
• pp.116-120
• /
• 2007

The synthesis of 1-[2-(3-{7-oxabicyclo[4.1.0]heptyl} 1,1,3,3-tetramethyl-disiloxane (Mono), which is a key intermediate for the synthesis of monomers applied for photopolymer systems based on the cationic ring opening polymerization, was studied. Mono was successfully synthesized by the hydrosilylation reaction of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) with an excess amount of 1,1,3,3-tetramethyldisiloxane (TMDS) in the presence of a Speier catalyst. The structure and the purity of Mono were characterized by FT-IR, $^1H-NMR$, and $^{29}Si-NMR$. The optimum conditions for the hydrosilyation reaction were found to be 1:4 molar ratio of VCHO to TMDS and 5 ppm of the catalyst at the temperature of $55^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.4
• /
• pp.409-412
• /
• 2001

Poly(p-tert-butyltrimethoxymonopropyloxycalix[4]arene-methylsiloxane) (TBCX-MS) has been prepared and used as a stationary phase in isothermal capillary gas chromatographic separation of some positional isomers. Retention factors (k) and separatio n factors $(\alpha)$ for the isomers were measured and compared with those on poly(p-tert-butyl-dimethoxydipropyloxycalix[4]arene-tetramethyldisiloxane) (TBCX-TMDS), poly(dimethoxydipropyloxycalix[4]arenetetramethyl-disiloxane) (CX-TMDS). Most of the isomers investigated are well resolved on TBCX-MS. Retention of all the compounds decreases on the three phases in the order, TBCX-TMDS ${\geq}$ TBCX-MS > CX-TMDS. Similar retention values on TBCX-TMDS and TBCX-MS seem to indicate that retention property of the two phases is not significantly affected by the spatial position of the calixarene moiety.

• Macromolecular Research
• /
• v.12 no.2
• /
• pp.156-171
• /
• 2004

We describe the precision synthesis schemes of siloxane-containing polymers, i.e., the control of their molecular weight, stereoregularity, and higher-order structures. First, we found a new catalytic dehydrocoupling reaction of water with bis(dimethylsilyl)benzene to give poly(phenylene-disiloxane). Together with this reaction, we applied hetero-condensations to the synthesis of thermally stable poly(arylene-siloxane)s. The dehydrocoupling reaction was applied to the synthesis of syndiotactic poly(methylphenylsiloxane) and poly(silsesquioxane)s, which we also prepared by hydrolysis and deaminative condensation reactions. We discuss the tendency for loop formation to occur in the synthesis of poly(silsesquioxane) by hydrolysis, and provide comments on the design of functionality of the polymers produced. By taking advantage of the low energy barrier to rotation in the silicon-oxygen bond, we designed selective oxygen-permeable membrane materials and liquid crystalline materials. The low surface free energy of siloxane-containing systems allows surface modification of a blend film and the design of holographic grating materials.

• Resources Recycling
• /
• v.22 no.2
• /
• pp.18-21
• /
• 2013

In this study, surface modification of wood powder by atmospheric pressure plasma treatment was investigated. The composites were manufactured using wood powder and polypropylene(wood powder : PP = 55 wt% : 45 wt%). Atmospheric pressure plasma was treated as condition of 3KV, $17{\pm}1$KHz, 2 g/min. Helium was used as carrier gas and monomer such as hexamethyl-disiloxane(HMDSO) was used to modify surface property by plasma polymerization. The tensile strength of untreated waste wood powder(W3) and homogeneous wood powder(H3) were about 18.5 MPa, 21.5 MPa while the tensile strength of plasma treated waste wood powder(PW3) and homogeneous wood powder(PH3) were about 21.2 MPa, 23.4 MPa, respectively. And tensile strength of W3 and H3 were improved by 14.6% and 8.8%, respectively. From the results for mechanical property, morphological analysis, we obtained improved interfacial bonding of polypropylene and wood powder modified by plasma treatment.

• Polymer(Korea)
• /
• v.34 no.1
• /
• pp.52-57
• /
• 2010

The low viscous epoxy resin(bisphenol F) with carboxylic acid as the reductants was introduced for high performance and reliability in the ACA with a low melting point alloy filler system. The curing characteristics of the epoxy resin and temperature dependant viscosity characteristic of epoxy resin at the melting temperature of LMPA were investigated by dynamic mode of differential scanning calorimetry (DSC) and rheometer, respectively. Based on these thermo-rheological characteristics of epoxy resin and LMPA, the optimum process system was designed. In order to remove the oxide layer on the surface of LMPA particle, three different types of carboxyl acid-based reductant were added to the epoxy resin. The wetting angles were about $18^{\circ}$ for carboxypropyldisilioxane, and $20.3^{\circ}$ for the carboxy-2-methylethylsiloxane, respectively.

• Journal of the Korean Vacuum Society
• /
• v.15 no.5
• /
• pp.485-492
• /
• 2006

Two new copper(I) complexes with organic ligands, $[Cu^I(hfac)]_2(DVTMSO)$ and $[Cu^I(hfac)]_2(HD)$ (hfac=hexafluoroacetylacetonate, DVTMSO=1,2-divinylte-tramethyl-disiloxane, HD=1,5-hexadiene) were synthesized and used for copper metal-organic chemical vapor deposition. In these compounds, two Cu(hfac) fragments are bonded by one neutral ligand forming unusual structure with respect to other Cu(I) complexes. The compounds exhibited relatively high volatility and stability when compared to other copper(I) precursors. By using the reported compounds as precursors, a continuous Cu layer was not formed but the Cu islands were only observed. And the shape and size of Cu islands are significantly changed as a function of the substrate temperature.