Synthesis of QMD and QD polyorganosiloxanes from tetrakis(trimethylsiloxy)silane and palabora vermiculite

Journal of Materials Chemistry Pub Date: DOI: 10.1039/JM9940400399

Abstract

Tetrakis(trimethylsiloxy)silane (QM4)(Q = SiO4/2 and M = Me3SiO1/2) reacts with dimethyldichlorosilane in the presence of an iron(III) chloride hexahydrate catalyst to give chlorinated intermediates, e.g. QM3 Y (Y = Me2SiO1/2Cl), which upon hydrolysis give products which range from viscous liquid QMD (D = Me2SiO2/2) systems to QD elastomeric solids. Chlorinated QxYy intermediates have also been synthesized from high-molecular-weight Qx My polyorganosiloxanes derived from palabora vermiculite, and which react with hydroxy-terminated poly(dimethylsiloxanes)(HODnOH) to give a range of QD polymers. The Lentz trimethylsilylation of vermiculite has been modified with the hexamethyldisiloxane replaced by HODnOH as the capping agent to give QD polyorganosiloxanes via, a one-pot reaction. Selected QD polymers have undergone a flame test at 1100 °C to assess their potential as fire-retardant materials.

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