摘要 |
<p>A method is provided for making substantially pure anhydrous sodium salts of aromatic bisphenols, such as the disodium salt of 2,2-bis(p-hydroxyphenyl)propane. Rapid separation of water from a sodium salt of an aromatic bisphenol hydrate, or as an aqueous mixture having stoichiometric quantities of sodium hydroxide and bisphenol has been found to provide substantially pure anhydrous bisphenol alkali metal salts useful as intermediates for making polyetherimides.</p> |