Hydrosilylation of a,o-bis(trimethylsiloxy)-methylhydrosiloxane to alkenes in the presence of a catalyst was performed at several temperatures (30-708C). Combtype methylsiloxane oligomers with various alkyl substituted groups in the side chains have been obtained. Not all active BSiÀ ÀH groups participate in the reaction. The reaction order, activation energies, and rate constants have been determined. The synthesized oligomers were characterized by 1 H, 13 C, 1 H COSY NMR, and FTIR spectroscopy. Calculations using the quantum-chemical semiempirical AM1 method for modeling reaction between methyldimethoxysilane [Me(MeO) 2 SiH] and hexene-1 were performed to evaluate possible reaction paths. For all initial, intermediate, and final products, enthalpies of formation as a function of the distance between BCÀ ÀSiB bonds are calculated. The hydride addition is energetically more favorable according to the antiMarkovnikov rule than according to the Markovnikov rule. Comb-type oligomers were characterized by gel-permeation chromatography, differential scanning calorimetry, thermogravimetry, and wide-angle X-ray diffractometry.

ABSTRACT:The hydrosilylation reaction of ␣,-bis(trimethylsiloxy)methylhydridesiloxane to styrene and ␣-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 'SiOH groups did not take place. The hydrosilylation reaction order, activation energies. and rate constants were determined. The synthesized oligomers were characterized by 1 H, 13 C, 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 'COSi' 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.

ABSTRACT:The hydrosilylation reaction of ␣,-bis(trimethylsiloxy)methylhydridesiloxane to phenylacetylene in the presence of catalyst-platinum hydrochloric acid (0.1M solution in tetrahydrofuran)-at 1 : 35 ratio of initial compounds, at various temperatures (40 -60°C) was investigated and methylsiloxane oligomers with phenethenyl substituted groups in the side chain has been obtained. It was shown that complete hydrosilylation of all active (SiOH groups do not take place. The hydrosilylation reaction order, activation energy, and rate constants were found. The synthesized oligomers were characterized by 1 H and 13 C NMR and IR spectral data. Gel-permeation chromatographic, differential scanning calorimetric, thermogravimetric, and wide-angle X-ray investigations of synthesized oligomers were carried out.

The role of the structural peculiarities of electrical conducting polymer composites (ECPC) has been considered. Different conception on the nature of the conductivity, the mechanisms of charge transfer in heterogeneous structures are presented in this review. Experimental results obtained by different scientists are only partially in concordance with existing theoretical models. It is suggested that missing of various physical and chemical factors influencing the processes of electrical current formation in polymer composites is one of the main reasons of the mentioned divergence between theory and experimental results among which the rate of the values of inter-and intra-phase interactions in composites may be considered as a very important factor. The peculiarities of dependence of the conductivity of systems with binary conducting fillers are considered in this work as well.

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