Method for reducing oligomeric cyclic ether content of a polymerizate
AssigneeE. I. Du Pont de Nemours and Company
InventorHarry B. Copelin
Life of this patent
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Abstract
The oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide- or a tetrahydrofuran/alkylene oxide polymerizate can be reduced by bringing the polymerizate into contact with a gas in the supercritical state.
Claims10
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide-, or a tetrahydrofuran/alkylene oxide polymerizate, the method comprising
- (a) bringing the polymerizate into contact with a gas in the supercritical state, for a time sufficient to reduce said ether content, the gas having a critical temperature of 0.degree.-200.degree. C., and then
- (b) separating the gas and the polymerizate.
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/ethylene oxide- or a tetrahydrofuran/propylene oxide polymerizate, the method comprising bringing the polymerizate into contact with propylene in the supercritical state, for a time sufficient to reduce the ether content, and then separating the propylene and the polymerizate.
Dependencies are inferred from the claim text.