Effective Promotion of Tetrahydrofuran Polymerization Initiated with Heteropolyacid

摘要

Tetrahydrofuran was plymerized using the heteropolyacid H_3PW_12O_40 as the initiator and ethylene oxide as the promoter, which effectively increased the rate and conversion of the polymerization. Water and butylene glycol were used to control the molecular weight of the product in the range of 1000-3000. The polymer was found to be polyether glycol containing 10-22 mol % oxyethylene moieties with hydroxyl groups at both chain ends. The melting point was ～10 deg C lower compared to polytetramethylene ether glycol having the same molecular weight. The concentration of active species remained unchanged in the main period of the polymerization, indicating the absence of chain termination. The values of the chain propagation rate constant of tetrahydrofuran polymerization at 0 and 20deg C were found to be 3.78×10~(-3) and 1.98×10~(-2) L mol~(-1) s~(-1), respectivley, which are close to the rate constant of chain propagation of tetrahydrofuran on ionic active species.