PROCESS FOR POLYMERIZATION OF TETRAHYDROFURAN

1285002 Polymerizing tetrahydrofuran KAO SOAP CO Ltd 18 March 1970 [18 March 1969] 13061/70 Heading C3R Tetrahydrofuran is polymerized in the presense of fuming sulphuric acid and perchloric acid. The sulphuric acid has a concentration of 15 to 43 wt. per cent and is used in an amount of 8-40% based on the THF. The amount of perchloric acid is 0À05 to 20 wt.per cent based on the fuming sulphuric acid and may be 100% perchloric acid or its hydrate (60-70% acid). Temperatures of - 40‹ to 80‹ C. may be employed and the reaction system may be closed or open and with or without a solvent. Polymerization is terminated by addition of water and the mixture is heated to remove monomer and to hydrolyse the sulphuric acid ester radicals at the ends of the polymer. On standing at room temperature, an upper oily layer of the OH- terminated polymer separates and is neutralized, dehydrated and desalted to give colourless liquid or waxy polymers which can be converted to polyurethanes.