Formation of new thermoreactive polysiloxanes

Hydrosilylation of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane to propargyl alcohol in the presence of catalyst, platinum hydrochloric acid, was performed at several temperatures. Comb‐type methylsiloxane oligomers with substituted reactive groups in the side chain have been obtained. At the high stages of reaction, gelation takes place. Except hydrosilylation, also proceeds dehydrocondensation reaction with low yield. The synthesized oligomers were characterized by 1H‐NMR spectroscopy. Calculations by quantum‐mechanical semiempirical AM1 method for modeling reaction between methyldimethoxysilane [Me(MeO)2SiH] and propargyl alcohol were performed for fully characterization of hydride addition of polymethylhydrosiloxane to propargyl alcohol. For all initial, intermediate, and final products enthalpies of formation as a function of the distance between CSi bonds are calculated. Comb‐type oligomers were characterized by gel‐permeation chromatography, differential scanning calorimetry, thermogravimetry, and wide‐angle X‐ray diffractometry analyses. Crosslinking of synthesized oligomer using γ‐aminopropyltriethoxysilane was investigated and studied using DSC and TGA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2168–2173, 2007