摘要 |
Polytetramethylene ether glycols (PTMEG) are fractionated with liquid propane in an extractor under high pressure. Fractions are separated by altering the extraction pressure, which alters the solvent power of the propane. The polydispersities of all extracted PTMEG fractions are generally below 1.3. The addition of a cosolvent, preferably tetrahydrofuran, can effectively lower the initial extraction pressure and increase the efficiency of the extraction.
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