Ratio Of Initial Compounds Research Articles

Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

Abstract Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl acetoacetate and vinyltriethoxysilane at 1:3:1 ratio of initial compounds in the presence of Karstedt’s catalyst (Pt2[(VinSiMe2)2O]3), platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon have been studied and D4R,R’ type methylorganocyclotetrasiloxane has been obtained. Ring-opening co-polymerization reactions of methylorganocyclotetrasiloxane and hexamethyldisiloxane, in the presence of catalytic amount of powder-like potassium hydroxide, have been carried out and linear methylsiloxane oligomer with regular arrangement of propyl acetoacetate and triethoxysilane groups in the side chain has been obtained. The synthesized methylorganocyclotetrasiloxane and oligomers were studied by FTIR, 1H, 13C, 29Si NMR spectroscopy. Comb-type oligomers were characterized by gel-permeation chromatography, wide- angle X-ray and differential scanning calorimetric methods. Via sol-gel processes of doped with lithium trifluoromethylsulfonate (triflate) or lithium bis- (trifluoromethylsulfonyl)imide oligomer systems solid polymer electrolyte membranes have been obtained. The dependence of ionic conductivity as a function of temperature and salt concentration has been studied. The electrical conductivity of these materials at room temperature belongs to the range of 7x10-8 to 4x10-6 S cm-1 and depends on the structures of grafted anion receptors and the polymer backbones.

Synthesis of thermoreactive polysiloxanes with cyclic fragments in the side chain

AbstractThe synthesis of polysiloxanes with pendant unsaturated cyclic fragments have been successfully performed by hydrosilylation reactions of polymethylhydrosiloxane with 4‐vinyl‐1‐cyclohexene in the presence of platinum hydrochloric acid (0.1 M solution in THF), Karstedt's catalyst (Pt2[(VinSiMe2)2O]3) and platinum on the charcoal (5%). Reactions were carried out at various temperatures with different ratios of initial compounds. It was shown, that not all active ≡SiH groups take part in the hydrosilylation reaction. Some kinetic parameters of reactions were studied. The synthesized oligomers were characterized by FTIR, 1H, 13C, H,H‐COSY, and C,H‐correlation NMR spectroscopy. Calculations using the quantum‐chemical semi empirical AM1 method for modeling reactions between methyldimethoxysilane [Me(MeO)2SiH] and 4‐vinyl‐1‐cyclohexene were performed to evaluate possible reaction paths. Synthesized oligomers were characterized by gel‐permeation chromatography, differential scanning calorimetric, thermogravimetric, and wide‐angle X‐ray analyses. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Comb‐type methylsiloxane copolymers with diorganosilylene fragments as a lateral group

AbstractThe catalytic dehydrocondensation reaction of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane and of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane‐dimethylsiloxane with α‐hydroxy‐ω‐trimethylsiloxydiorganosilylenes, in the presence of anhydrous caustic potassium, at 1:35 and 1:33 ratio of initial compounds has been investigated and polyorganosiloxanes with rigid polydiorganosilylenes fragment in the side chain, completely soluble in organic solvents, have been obtained. The catalytic dehydrocondensation reaction order, activation energies, and rate constants have been determined. The synthesized copolymers were characterized by thermogravimetric, gel permeation chromatographic, differential scanning calorimetric, and wide‐angle X‐ray analyses. It was shown that during modification of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane‐dimethylsiloxane with α‐hydroxy‐ω‐trimethylsiloxydiorganosilylenes in synthesized block‐copolymers, microdomain structure (phase incompatibility) was observed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2161–2167, 2007

Methylsiloxane Oligomers with Oxyalkyl Fragments in the Side Chain

AbstractThe dehydrocondensation reactions of α,ω–bis(trimethylsiloxy)methylhydridesiloxane with saturated primary n‐alcohols in the presence of anhydrous powder‐like potassium hydroxide or platinum on the carbon (Pt/C‐5%) at 1:30 ratio of initial compounds, at various temperature (40–60 °C) was carried out, and methylsiloxane oligomers with n‐alkyloxy substituted groups in the side chain were obtained. It was shown that completely dehydrocondensation of all active SiH groups do not take place. Dehydrocondensation reaction order, activation energy and rate constants were found. The synthesized oligomers were characterized by 1H, 13C NMR, Cosy and FTIR spectra data. Gel‐permeation chromatography, differential scanning calorimetric, thermogravimetric and wide‐angle X‐ray investigations of synthesized oligomers were carried out.

Synthesis of New Methylsiloxane Oligomers with Pendant Trialkoxysilylethyl Groups for Preparation of Silicon hard Coatings

AbstractFor the purpose to prepare precursor materials for the silicon hard coatings, the hydrosilylation reactions of α, ω–bis(trimethylsiloxy)methylhydridesiloxane to trialkoxyvinylsilanes in the presence of platinum hydrochloric acid (0.1 M solution in THF), Karstedt's catalyst (Pt2[(VinSiMe2)2O]3) and platinum on the carbon (5%) were investigated. Hydrosilylation reactions at different ratios of initial compounds and at various temperatures (40–60 °C) were investigated and methylsiloxane oligomers with pendant trialkoxy fragments have been obtained. It was shown that completely hydrosilylation of all active SiH groups do not take place. The hydrosilylation reaction order, activation energy and rate constants were determined. The synthesized oligomers were characterized by 1H, 13C NMR and FTIR spectra data. Gel‐permeation chromatography, differential scanning calorimetric, thermogravimetric and wide‐angle X‐ray investigations of synthesized oligomers were carried out. Synthesized oligomers together with tetraethoxysilane were used for preparation of silicon hard coatings via sol‐gel processes.

Modification Reactions of Methylhydrosiloxanes with Tricyclodecadiene

AbstractThe reaction of hydride polyaddition of methylhydridesiloxane and methylhydridesiloxane‐dimethylsiloxane oligomers to unsaturated carbocyclic compound ‐ tricyclodecadiene, at the various ratio of initial compounds, in the presence of platinum hydrochloric acid has been investigated. It was shown that hydrosilylation reaction proceeds both to 1.2 and 9.10 positions and by intermolecular with formation of branching systems. The polyorganosiloxanes with tricyclodecenyl fragment in the side chain, completely soluble in organic solvents were synthesized. For fully characterization of hydride addition of methylhydridesiloxane to tricyclodecadiene, by quantum‐chemical half empiric AM1 method, for all initial, intermediate and final products, in modelling reaction of hydrosilylation of methyldimethoxysilane to tricyclodecadiene, the heats of formations (ΔHf), change of energy (ΔH) of the system depending on the change of distance (RC‐Si) between C‐Si bonds, also the charges values (q) on the atoms, dipole moments (µ) and bonds orders (Pij) are calculated. It was concluded, that the course of hydride addition of modelling reaction of methyldimethoxysilane to tricyclodecadiene energetically is more favourable by 9.10‐addition. The hydride polyaddition reaction order, activation energies and rate constants were found. The synthesized oligomers were characterized by 1H and 13C NMR, FTIR, thermogravimetry, gel permeation chromatography, differential scanning calorimetry and wide angle X‐ray methods.

Poly(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane‐poly(dimethylsiloxane) block copolymers

AbstractThe heterofunctional condensation of 1,3‐dichloro‐1,3‐disila‐1,3‐diphenyl‐2‐oxaindane with dihydroxydiphenylsilane at various ratios of initial compounds in the presence of amines was carried out, and α,ω‐dihydroxy(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane oligomers with various degrees of condensation were obtained. Corresponding block copolymers were obtained by heterofunctional polycondensation of synthesized α,ω‐dihydroxy(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane oligomers with α,ω‐dichlorodimethylsiloxanes in the presence of amines. Thermogravimetry, gel permeation chromatography, differential scanning calorimetry, and wide‐angle X‐ray analysis were carried out on the synthesized block coplymers. Differential scanning calorimetry and wide‐angle X‐ray studies of these copolymers showed that their properties were determined by the ratio of the lengths of the flexible linear poly(dimethylsiloxane) and rigid poly(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane fragments in the main macromolecular chain. Two‐phase systems were obtained with specific flexible and rigid fragment length values in synthesized block copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3462–3467, 2006

Hydrosilylation reactions of methylhydridesiloxane to styrene and α‐methylstyrene

AbstractThe hydrosilylation reaction of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane to styrene and α‐methylstyrene in the presence of the catalyst platinum hydrochloric acid (a 0.1M solution in tetrahydrofuran) at a 1:35 ratio of initial compounds at various temperatures (80–90°C) was investigated, and methylsiloxane oligomers with aryl‐substituted groups in the side chain were obtained. Complete hydrosilylation of all active SiH groups did not take place. The hydrosilylation reaction order, activation energies. and rate constants were determined. The synthesized oligomers were characterized by 1H, 13C, and IR spectral data. For the full characterization of the hydride addition of methylhydridesiloxane to styrene by the quantum‐chemical half‐empiric Austin Model 1 (AM1) method for all initial, intermediate, and final products, in the modeling of the hydrosilylation reaction of methyldimethoxysilane to styrene, the heats of formation, energy changes of the system depending on the change of distance between CSi bonds, and the charge values on the atoms, dipole moments, and bond orders were calculated. The synthesized oligomers were characterized by gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, and wide‐angle X‐ray diffraction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 388–394, 2006

Dehydrocondensation and hydrosilylation reactions of methylhydridesiloxane with allyl alcohol

The reaction of dehydrocondensation of f , y -bis(trimethylsiloxy)methylhydridesiloxane (n , 53) with allyl alcohol at various ratios of initial compounds, in the presence of anhydrous powders like caustic potassium and platinum chlorohydric acid has been investigated. It was established that in the presence of caustic potassium dehydrocondensation reaction takes place and methylsiloxane oligomers with allylic groups in side chain have been obtained. In the presence of platinum chlorohydric acid competetive dehydrocondensation and hydrosilylation reactions take place with formation of oligomers with various chain links. In late stages of the reaction three-dimensional systems were obtained. During dehydrocondensation the reaction order, reaction rate constants and activation energy were found. The structure of the synthesized oligomers were determined by IR and NMR spectra data. Gel permeation chromatography, differential scanning calorimetric and X-ray analysis of the synthesized oligomers were carried out.

Synthesis and investigation of properties of silaoxadihydrophenanthrene‐diphenylsiloxane fragments containing block copolymers

AbstractThe reaction of heterofunctional condensation of 1,1‐dichloro‐1‐sila‐2‐oxadihydrophenanthrene with dihydroxydiphenylsilane at various ratios of initial compounds in the presence of pyridine is investigated. α,ω‐Dihydroxysilaoxadihydrophenanthrene‐diphenylsiloxane oligomers with various degrees of condensation are obtained. Organosiloxane block copolymers with the regular arrangement of silaoxadihydrophenanthrene‐diphenylsiloxanes fragments in the main linear dimethylsiloxane chain are produced by the reaction of heterofunctional condensation of α,ω‐dihydroxysilaoxadihydrophenanthrene‐diphenylsiloxanes with α,ω‐dichlorodimethylsiloxanes in the presence of anhydrous pyridine, as an acceptor of hydrochloric acid. Thermogravimetry, differential scanning calorimetry, gel permeation chromatography, and wide‐angle X‐ray analysis are carried out on the synthesized block copolymers. The microheterogeneous structure of block copolymers is observed at definite values of the length of the flexible dimethylsiloxane chain by DSC and X‐ray investigation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 9–16, 2002; DOI 10.1002/app.10045

Arylenecyclosiloxane–dimethylsiloxane copolymers

The heterofunctional condensation reaction of 1,4-bis(phenyldichlorosilyl)benzene with dihydroxydiphenylsilane at a 1:4 ratio of initial compounds in the presence of pyridine was investigated and tetrakis(hydroxydiphenylsiloxy)-1,4-bis(phenylsilyl)benzene was obtained. The heterofunctional condensation of the tetrakis(hydroxydiphenylsiloxy)-1,4-bis(phenylsilyl)benzene with organotrichlorosilanes at a 1:2 ratio of initial compounds in the presence of pyridine produced dichloro-containing arylenecyclosiloxanes. The dichloro-containing arylenecyclosiloxanes were obtained in one stage by successive heterofunctional condensation of 1,4-bis(dichlorophenylsilyl)benzene with dihydroxydiphenylsilane and organotrichlorosilanes in a 1:4:2 ratio in the presence of pyridine. It was established that the yields of dichloro-containing products were lower. Hydrolysis of dichloroarylenecyclosiloxanes in a neutral condition produced corresponding dihydroxy compounds. Heterofunctional polycondensation of dicloro(dihydroxy)arylenecyclosiloxanes with α,ω-dihydroxy(bisdimethylamino)dimethylsiloxanes was used to obtain arylenecyclosiloxane-dimethylsiloxane copolymers. Thermogravimetric, thermomechanical, and roentgenographic investigations of the synthesized copolymers were carried out. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3142–3148, 2001

Arylenecyclosiloxane–dimethylsiloxane copolymers

AbstractThe heterofunctional condensation reaction of 1,4‐bis(phenyldichlorosilyl)benzene with dihydroxydiphenylsilane at a 1:4 ratio of initial compounds in the presence of pyridine was investigated and tetrakis(hydroxydiphenylsiloxy)‐1,4‐bis(phenylsilyl)benzene was obtained. The heterofunctional condensation of the tetrakis(hydroxydiphenylsiloxy)‐1,4‐bis(phenylsilyl)benzene with organotrichlorosilanes at a 1:2 ratio of initial compounds in the presence of pyridine produced dichloro‐containing arylenecyclosiloxanes. The dichloro‐containing arylenecyclosiloxanes were obtained in one stage by successive heterofunctional condensation of 1,4‐bis(dichlorophenylsilyl)benzene with dihydroxydiphenylsilane and organotrichlorosilanes in a 1:4:2 ratio in the presence of pyridine. It was established that the yields of dichloro‐containing products were lower. Hydrolysis of dichloroarylenecyclosiloxanes in a neutral condition produced corresponding dihydroxy compounds. Heterofunctional polycondensation of dicloro(dihydroxy)arylenecyclosiloxanes with α,ω‐dihydroxy(bisdimethylamino)dimethylsiloxanes was used to obtain arylenecyclosiloxane‐dimethylsiloxane copolymers. Thermogravimetric, thermomechanical, and roentgenographic investigations of the synthesized copolymers were carried out. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3142–3148, 2001

Comb-type Organosilicon Compounds with Epoxy Groups in the Side Chain

The reaction of hydride addition of α,ω-bis(trimethylsiloxy)methylhydridesiloxanes with allyl glycidyl ether in the presence of platinum chlorohydric acid and Pt/C at the 1:30 ratio of initial compounds has been studied. It was established that when the reaction proceeds without solvent, three-dimensional systems are obtained. The optimal condition of hydride addition reaction, concentration of the solution, the reaction temperature have been determined. The reaction order, activation energy and hydride addition rate constants were found. In the case of platinum chlorohydric acid hydride addition proceeds with inductive period, and faster than in the case of the catalyst platinum on the carbon Pt/C. The reactions of primary and secondary amines with epoxy groups containing organosiloxanes were carried out and comb-type organosiloxanes with aminohydroxy groups in the side chain have been obtained. After protonation of amino nitrogen groups in the side chain water soluble organosiloxane oligomers were obtained. The structure of all synthesized comb-type organosiloxanes were determined by IR, 1H and 13C NMR spectra data.

Hydride Addition of Methylhydridesiloxanes to Dicyclopentadiene

The reaction of hydride polyaddition of methylhydridcsiloxanes to unsaturated carbocyclic compound–dicylopentadiene, at the ratio of initial compounds 1:53 and 1:30, in the presence of platinum chlorohydric acid has been investigated. The hydride poly-addition reaction order, activation energies and rate constants were found. The poly-organosiloxanes with tricyclodecenyl fragment in the side chain, completely dissoluble in organic solvents were synthesized. The synthesized oligomers were characterized by 1H and 13C NMR, IR, thermogravimetric, gel permeation chromatographic, differential scanning calorimetric and X-ray methods.

The Influence of a Quartz Surface on the Transformation of Molybdenite under the Action of Hydrogen Oxidation

The process of the transformation of powdered molybdenite (MoS2) under the action of hydrogen oxidation is studied under the conditions of adding quartz pieces, different in shape and size. The investigation is carried out in flow-type conditions at an atmospheric pressure and 873 K. The time of contact with the gas phase, where the hydrogen oxidation takes place, is 38 s. The ratio of initial compounds is PH2P_{H_2} : Pair= 3 : 1. It is shown that the presence of quartz pieces increases the degree of molybdenite desulfurization.

Rheokinetic studies of the synthesis and properties of elastomers based on the oligodiene dihydrazides and unsaturated dicarboxylic imides

Rheokinetic methods were used to investigate the synthesis of elastomers from oligoisoprene dihydrazide and maleic acid bis-imides. The effect of the bis-imide structure, temperature-time parameters and the ratio of initial compounds in the rheokinetics of synthesis of cured compositions and on their deformation-strength properties has been investigated. A crosslinking mechanism is proposed, taking account of the reaction between terminal hydrazide and maleimide functional groups, as well as homopolymerization of maleimide. The feasibility of reinforcement of the obtained elastometer by active fillers has been ascertained.