| 摘要 |
<p>1326526 Catalytic polymerization of tetrahydrofuran KAO SOAP CO Ltd 15 Sept 1971 [16 Sept 1970] 42981/71 Heading C3R Tetrahydrofuran is polymerized at- 40 to +80‹ C. in the absence of water and in the presence of 5 to 50% by weight of fuming sulphuric acid (based on the weight oftetrahydrofuran) and also 0À01 to 70 mol per cent of a fluorine-containing compound based on the free SO 3 in the fuming sulphuric acid. The terminal groups of the resulting polymer are subjected to a hydrolysis step to provide the required hydroxy-terminated polymer. The process may be carried out in the presence of a solvent, e.g. 1, 2-dichloroethane, or in the absence of a solvent. Fluorine-containing compounds are suitably sodium, potassium and ammonium fluorides, fluorosulphonic and borofluoric acids, ammonium and potassium borofluorides, boron trifluoride and ether complexes thereof, fluorobenzene, fluorotoluene, 2-fluoroethanol, trichlorofluoromethane and trichlorotrifluoroethane. Examples describe the preparation of polytetrahydrofurans having molecular weights of from 888 to 6222.</p> |
