Sulfuric Acid → CID 3084433

Participants

Reaction Conditions

Reaction Steps

In the same reaction apparatus as in Example 15, 100 g of 25% fuming sulfuric acid was dropped into 500 g of tetrahydrofuran at -20° C. over 40 minutes, and then the resulting mixture was subjected to reaction at -20° C. for 2 hours. The conversion at this point was 31%. Then the reaction mixture was heated to 10° C. and subjected to reaction for 2 hours, after which 10 g of water was added to the mixture to terminate the polymerization. The final conversion was 58%. Thereafter, 400 g of water was added to the polymerization mixture, and the dropping funnel was replaced by the distilling column, after which the contents in the flask were heated and hydrolyzed in an oil bath at 100° C. with stirring for 2 hours while distilling off and recovering unreacted tetrahydrofuran. Then, the contents in the flask were allowed to stand at 100° C. to cause separation of layers and the aqueous layer was withdrawn. To the obtained PTMG layer were again added 230 g of water and 20 g of the withdrawn aqueous layer, and the resulting mixture was refluxed with heating and hydrolyzed in an oil bath at 120° C. with stirring for 2 hours and then allowed to stand at 100° C. to cause separation of layers, after which the separated aqueous layer was withdrawn. The amount of residual sulfuric ester groups in PTMG was 5 ppm and the acid number was 0.21. To the resulting PTMG layer was further added 250 g of water having suspended therein 0.25 g of basic magnesium carbonate, and the resulting mixture was subjected to heating and washing treatment in an oil bath at 100° C. for one hour while stirring the mixture vigorously, after which the mixture was allowed to stand to cause separation of layers. The mixture was not emulsified throughout the treatment, and upon allowing the mixture to stand, the mixture underwent separation of layers in a very short time, and the PTMG layer after the separation of layers was almost transparent. After removing the aqueous layer, the PTMG layer was subjected to perfect evaporation of volatile matters under reduced pressure at 80° C., and then filtered through a 10-μ mesh membrane filter to obtain 260 g of colorless transparent PTMG (yield: 52%). The thus obtained PTMG was analyzed to determine its number-average molecular weight, hydroxyl number, acid number, and amount of residual sulfuric ester groups, all of which are shown in Table 3.

Provenance & Evidence