New Polyorganosiloxanes Prepared from Silicate Minerals.

摘要

Several novel polyorganosiloxane systems have been prepared by the physical and chemical modification of inorganic polymers resulting from the trimethylsilylation of minerals such as biotite, muscovite, thuringite and wollastonite. The extensive study of the trimethylsilylation step itself has given detailed information about the isomorphous replacement of silicon by aluminium in the silicate backbone, and the polymers produced by this step are interesting in themselves, showing marked stability to acid and base attack. The modification of this initial or pre-polymer by a variety of physical and chemical techniques has led to a number of interesting systems: (1) Thermal polymerisation gives high molecular weight products with molecular wt. of approx. 6000; (2) Reaction through pendant hydroxyl groups with (CH3)3SiCl, Ph2PCl, SOCl2, (Ch2=CH)(CH3)SiCl2, CH2=CHSiCl3 gives functionally substituted polyorganosiloxanes; and (3) Reaction with (CH3)2SiCl2 in the presence of hydrated ferric chloride gives products with molecular wt. of approx. 6000 containing labile chlorine atoms. Finally, the reactivity of the methyl groups (CH3)3Si on the polyorganosiloxanes was investigated and it was shown that they will react to give halogen precursors which can be used to give polyorganosiloxanes containing alcoholic and ester groupings. (Author)