Condensation of α,ω-Oligodimethylsiloxanols in Ammonia: A New Method for the Synthesis of Polydimethylsiloxanes with the Low Content of Cyclosiloxanes

Abstract

A new efficient approach to the production of high molecular weight polydimethylsiloxanes (PDMSs) is developed based on the condensation of α,ω-oligodimethylsiloxanols in ammonia. This method provides control over the molar mass of the target PDMSs in a wide range (Mw = 11.0–82.0 kg/mol). The use of cyclic silazanes as dehydrating agents allows for suppressing the side cyclization processes.