Sulfuric Acid → CID 3084433

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence