Claims
- 1. A polymerizate containing a copolymer of tetrahydrofuran and ethylene oxide, the copolymer containing 10-80%, by weight, of ethylene oxide and having a number average molecular weight of 500-10,000 and a hydroxyl functionality of 2.0-4.0, the polymerizate containing no more than about 3%, by weight of oligomeric cyclic ethers.
- 2. The polymerizate of claim 1 containing no more than about 2%, by weight, of oligomeric cyclic ethers.
- 3. The polymerizate of claim 1 containing no detectable oligomeric cyclic ethers.
- 4. The polymerizate of claim 1 wherein the copolymer contains 20-60%, by weight, of ethylene oxide, has a number average molecular weight of 650-5000 and a hydroxyl functionality of 2.0-2.5.
- 5. A method for producing the polymerizate of claim 1, the method comprising extracting oligomeric cyclic ethers from a raw polymerizate with water, until the polymerizate contains no more than about 3%, by weight, of oligomeric cyclic ethers.
- 6. The method of claim 1, in which, before the water extraction is performed, the raw polymerizate is distilled until its oligomeric cyclic ether content is about 5%, by weight.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 887,333, filed Mar. 16, 1978, and application Ser. No. 967,082, filed Dec. 12, 1978, both now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (1)
Number |
Date |
Country |
854958 |
Nov 1960 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Hammond et al., "Cationic Copolymerization of Tetrahydrofuran with Epoxides", J. Polymer Science, Part A-1, vol. 9, 281-294, (1971). |
Korovina et al., "Formation of a Cyclic Propylene Oxide Tetramer During Copolymerization", Vysokomolekulyarnye Soedineniya (B)17, 597-600, (1975). |
Related Publications (1)
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Number |
Date |
Country |
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967082 |
Dec 1978 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
887333 |
Mar 1978 |
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