Claims
- 1. A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate, the method comprising bringing the polymerizate into contact, at a temperature of 60.degree.-150.degree. C., with 0.5-25% , by weight of the polymerizate, of a cationic ion exchange resin bearing --SO.sub.3 H groups, insoluble in the reaction medium, for a time sufficient to significantly reduce the oligomeric cyclic ether content of the polymerizate.
- 2. The method of claim 1 conducted while byproducts are withdrawn from the reaction zone.
- 3. The method of claim 1 wherein the ion exchange resin is a macroreticular resin having a backbone which is crosslinked copolymer of styrene and divinyl benzene and an initial hydrogen ion concentration of about 4.9 milliequivalents per gram (dry), an initial surface area of about 40-50 square meters per gram, an initial porosity of 0.3-0.35 milliliter of pore per milliliter of bead, and an initial average pore diameter of 200-600 Angstrom units.
- 4. The method of claim 1 wherein the ion exchange resin is a copolymer of tetrafluoroethylene and a monomer represented by the structure ##STR3## hydrolyzed to the acid form.
- 5. The method of claim 1 run at a temperature of 90.degree.-110.degree. C.
- 6. The method of claim 1 wherein the concentration of ion exchange resin is 3-7%, by weight of the polymerizate.
- 7. The method of claim 1 wherein the polymerizate is of a tetrahydrofuran/ethylene oxide copolymer.
- 8. The method of claim 1 wherein the polymerizate is of a tetrahydrofuran/ethylene oxide copolymer, the ion exchange resin is the resin of claim 3 at a concentration of 3-7%, by weight of the polymerizate, byproducts are withdrawn from the reaction zone and the method is run at a temperature of 90.degree.-110.degree. C.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 887,332, filed Mar. 16, 1978, now abandoned.
US Referenced Citations (3)
Non-Patent Literature Citations (2)
Entry |
Murbach et al., "Linear Polyurethanes from Polyalkylene Ether Glycols", Chem. Abstracts 55, 1057e (1961). |
Rohm & Haas Co., Ion Exchange Department, Technical Bulletin-Amberlist 15. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
887332 |
Mar 1978 |
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