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Keywords:

  • hydrosilylation;
  • methylhydrosiloxane oligomers;
  • cross-linking;
  • kinetics

Abstract

The 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[BOND]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