Water → CID 3084433

Temperature

20 °C

In the same manner as in Example 17, a solution prepared by dissolving 1.5 g of sodium borofluoride in 55 g of 25% fuming sulfuric acid was dropped into 500 g of tetrahydrofuran at -10° C. over 30 minutes, and the mixture was subjected to reaction at -10° C. for one hour. The conversion at this point was 20%. Then the reaction mixture was heated to 20° C. and subjected to reaction at this temperature for 2 hours. The final conversion was 61%. Then, to the polymerization product was added 520 g of water and heated in an oil bath at 80° C. with stirring for 2 hours while distilling off and recovering the unreacted tetrahydrofuran. Then, the oil bath temperature was elevated to 100° C. and 50 g of a 48% by weight aqueous sodium hydroxide solution was added continuously over a period of one hour to accomplish the hydrolysis of the reaction mixture. Recovery of the unreacted tetrahydrofuran was continued during said addition, and upon completion of said addition, the mixture was allowed to stand at 100° C. to cause the separation of layers. The aqueous layer was withdrawn, and to the remaining PTMG layer was added 250 g of water and a part of the withdrawn aqueous layer, after which the sulfuric acid concentration in the aqueous layer was adjusted to about 1% by weight, and the mixture was again heated and stirred in an oil bath at 100° C. for 2 hours to complete the hydrolysis and then allowed to stand at 100° C. to cause separation of layers. A part of the separated PTMG layer was sampled and analyzed to determined the amount of residual sulfuric ester groups and acid number. They were 4 ppm and 0.27, respectively. Then, without withdrawing the aqueous layer, 9.7 g of a 20% by weight aqueous sodium hydroxide solution was added and the mixed system was heated and stirred in an oil bath at 80° C. for about 15 minutes and then, 1.3 g of a 15% by weight aqueous suspension of a basic magnesium carbonate to adjust the pH of the mixture about 8, followed by additional heating and washing with stirring in an oil bath at 80° C. for 2 hours. Then, the mixture was allowed to stand to cause separation of layers. The mixture showed no emulsification phenomenon throughout the treatment, the separation of layers was easy, and the separated PTMG layer was only slightly turbid. After removing the aqueous layer, the remaining PTMG layer was treated in the same manner as in Example 17 to obtain PTMG. Its analytical results are shown in Table 3.

1. customIn the same manner as in Example 17, a solution prepared
2. customthe mixture was subjected to reaction at -10° C. for one hour
3. customsubjected to reaction at this temperature for 2 hours
4. temperatureheated in an oil bath at 80° C.
5. distillationwhile distilling off
6. customrecovering the unreacted tetrahydrofuran
7. customwas elevated to 100° C.
8. addition50 g of a 48% by weight aqueous sodium hydroxide solution was added continuously over a period of one hour
9. customthe hydrolysis of the reaction mixture
10. additionaddition
11. additionupon completion of said addition
12. customto stand at 100° C.
13. customthe separation of layers
14. customThe aqueous layer was withdrawn
15. additionto the remaining PTMG layer was added 250 g of water
16. concentrationa part of the withdrawn aqueous layer, after which the sulfuric acid concentration in the aqueous layer
17. temperaturethe mixture was again heated
18. stirringstirred in an oil bath at 100° C. for 2 hours
19. customthe hydrolysis
20. customto stand at 100° C.
21. customseparation of layers
22. aliquotA part of the separated PTMG layer was sampled
23. customThen, without withdrawing the aqueous layer, 9.7 g of a 20% by weight aqueous sodium hydroxide solution
24. additionwas added
25. temperaturethe mixed system was heated
26. stirringstirred in an oil bath at 80° C. for about 15 minutes
27. addition1.3 g of a 15% by weight aqueous suspension of a basic magnesium carbonate
28. temperatureby additional heating
29. washwashing
30. stirringwith stirring in an oil bath at 80° C. for 2 hours
31. customseparation of layers
32. customthe separation of layers
33. customAfter removing the aqueous layer
34. additionthe remaining PTMG layer was treated in the same manner as in Example 17

ORD record

ord-b1d42c2a03ac4cf39aa3227fa23d28f5

Source dataset

uspto-grants-1983_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04371713