| 摘要 |
<p>Polyethersulfones derived from dihydroxybiphenyl or dehydroxybenzenes, especially 4,4'-dehydroxybiphenyl, are isolated by crystallization form a solvent, preferably a water-immiscible aromatic solvent. Crystallization may be achieved by cooling from the reaction temperature to a temperature in the range of about 20-100 °C, optionally with the use of a crystallization aid such as preformed polyethersulfone crystals. The crystallized polyethersulfone is then separated by filtration and by-product salts are removed therefrom by extraction with water.</p> |
