Tetrahydrofuran polymerization initiated by heteropolyacid in the presence of ethylene oxide: Reaction behavior of water and glycol

The reaction behavior of water and low molecular weight glycol in tetrahydrofuran polymerization initiated by H3PW12O40 in the presence of ethylene oxide has been studied. A lot of water was used in the hydrolysis reaction of ethylene oxide at the early stage of the polymerization and transformed into ethylene glycol (EG), which was consumed subsequently through a chain transfer reaction. EG was more reactive both than 1,4-butylene glycol and hexamethylene glycol toward propagating species, and the reaction rate constants at 0 degrees C were determined by GC to be 0.142, 8.83 x 10(-2), and 5.53 x 10(-2) L mol(-1).s(-1), respectively. The molecular weight of the product can be predicted by an equation based upon conversion of polymerization and the concentrations of molecular weight controller and H3PW12O40. (C) 1999 John Wiley & Sons, Inc.