Sulfuric Acid → CID 3084433

In the same reaction apparatus as in Example 15, 120 g of 25% fuming sulfuric acid was dropped from the dropping funnel into 600 g of tetrahydrofuran at -20° C. with stirring over a period of 40 minutes, and then the resulting mixture was subjected to reaction at -20° C. for 2 hours. The conversion at the end of this reaction was 32%. Then, the internal temperature was elevated to 10° C., at which the mixture was subjected to reaction for 2 hours. Thereafter, 10 g of water was added to terminate the polymerization. The final conversion was 57%. Then, the dropping funnel was replaced by the distilling column, and the contents in the apparatus were stirred vigorously and mixed with a solution prepared by dissolving 52 g of sodium hydroxide in 250 g of water (neutralization degree: 50%, corresponding to 20% by weight sulfuric acid concentration), and the mixture was heated and hydrolyzed in an oil bath at 80° C. for 2 hours while recovering unreacted tetrahydrofuran. In the same manner as in Example 15, the reaction mixture was allowed to stand to cause separation of layers. The aqueous layer was withdrawn and the PTMG layer was subjected twice to a heating and washing treatment with 300 g of a 15% by weight sodium sulfate solution at 120° C. The residual unreacted tetrahydrofuran was recovered in the first treatment. Thereafter, the same treatment as in Example 15 was conducted and finally the reaction product was filtered through a 10-μ mesh membrane filter to obtain PTMG. The results of analyses thereof were as shown in Table 2.

1. customthe resulting mixture was subjected to reaction at -20° C. for 2 hours
2. customwas elevated to 10° C., at which
3. customwas subjected to reaction for 2 hours
4. customto terminate
5. customthe polymerization
6. stirringthe contents in the apparatus were stirred vigorously
7. additionmixed with a solution
8. customprepared
9. temperaturethe mixture was heated
10. waithydrolyzed in an oil bath at 80° C. for 2 hours
11. customwhile recovering unreacted tetrahydrofuran
12. customseparation of layers
13. customThe aqueous layer was withdrawn
14. washwashing treatment with 300 g of a 15% by weight sodium sulfate solution at 120° C
15. customThe residual unreacted tetrahydrofuran was recovered in the first treatment
16. filtrationfinally the reaction product was filtered through a 10-μ mesh membrane
17. filtrationfilter

ORD record

ord-6b1ef7e46d8341e1bb684a6f6652773e

Source dataset

uspto-grants-1983_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04371713