Sulfuric Acid → CID 3084433

Temperature

80 °C

In the experiment in Example 17, the amount of 25% fuming sulfuric acid was changed to 180 g and the dropping thereof was conducted over one hour. The conversion after this treatment was 12%. Upon completion of said dropping, the internal temperature was elevated to 30° C. and the reaction was continued for one hour. Then, 130 g of water was added to terminate the polymerization and the conversion was measured. It was 52%. After replacing the dropping funnel by the distilling column, a solution prepared by dissolving 101 g of sodium hydroxide in 130 g of water was added continuously over one hour and heated in an oil bath at 80° C., and after said addition, the mixture was further heated and hydrolyzed at 80° C. for one hour. Unreacted tetrahydrofuran was simultaneously recovered by distillation during this operation. Then, a solution prepared by dissolving 23 g of sodium hydroxide in 25 g of water was added again continuously over one hour. At the same time, the oil bath temperature was raised to 100° C., and the mixture was heated and hydrolyzed while recovering unreacted tetrahydrofuran. After this treatment, the reaction mixture was allowed to stand to cause separation of layers, after which approximately 90% of the aqueous layer was taken out, and to the residue was added 150 g of a 20% by weight aqueous sodium sulfate solution and the resulting mixture was subjected to a heating and washing treatment at 100° C. for 2 hours. Then, in the same manner as in the preceding Examples, the aqueous layer was removed and the PTMG layer was again subjected to a heating and washing treatment at 80° C. for 30 minutes, after which the same operation was repeated once more. The resulting product was treated in the same way as in Example 17 to obtain PTMG. The results of its analyses are shown in Table 2.

1. customwas elevated to 30° C.
2. waitthe reaction was continued for one hour
3. customto terminate
4. customthe polymerization
5. customa solution prepared
6. additionwas added continuously over one hour
7. additionaddition
8. temperaturethe mixture was further heated
9. waithydrolyzed at 80° C. for one hour
10. distillationwas simultaneously recovered by distillation during this operation
11. customThen, a solution prepared
12. additionwas added again continuously over one hour
13. temperatureAt the same time, the oil bath temperature was raised to 100° C.
14. temperaturethe mixture was heated
15. customwhile recovering unreacted tetrahydrofuran
16. customseparation of layers
17. additionto the residue was added 150 g of a 20% by weight aqueous sodium sulfate solution
18. washwashing treatment at 100° C. for 2 hours
19. washwashing treatment at 80° C. for 30 minutes
20. additionThe resulting product was treated in the same way as in Example 17

ORD record

ord-c1a8494b31e44988ac51f3efb9a3247a

Source dataset

uspto-grants-1983_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04371713