KOH and Si-O-Si bonds

Does KOH cleave all Si-O-Si bonds in the polymer or does it just react with monomer to form nonvolatile K2Si(CH3)2O?

KOH only needs to cleave one (1) bond in any polymer chain to render it non-volatile.  High boiling/high molecular weight dimethyl silicone oils do not need the KOH. However, they always contain volatile oligomers/monomers. It is therefore necessary to eliminate the vaporization interference i.e. higher than normal responses from small molecular weight silicone oligomers or monomers such as hexamethyl disiloxane, hexamethylcyclotrisiloxane,  octamethycyclotetrasiloxane etc.  You can purchase, for example, one of these compounds from a chemical supply house and test/prove the validity of your method.  The hexamethylcyclotrisiloxane gives the biggest error making the sample look as if it contains more silicone than is actually present.

Serving you in chemistry,

Paul R. Gaines, Ph.D.
CEO of Inorganic Ventures & Fellow Chemist

DISCLAIMER: Advice offered by the chemists at Inorganic Ventures is intended for the individual posing the question. Feel free to contact us to verify whether these suggestions apply to your unique circumstances.