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New synthetic route of polyoxytetramethyleneglycol by use of heteropolyacids as catalyst
Author(s) -
Aoshima Atsushi,
Tonomura Shoichiro,
Yamamatsu Setsuo
Publication year - 1990
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1990.220010202
Subject(s) - polymerization , catalysis , tetrahydrofuran , molar mass distribution , polymer chemistry , phase (matter) , materials science , ring opening polymerization , molecule , hydrolysis , chemistry , organic chemistry , polymer , composite material , solvent
Polyoxytetramethyleneglycol (PTMG) can be directly prepared from tetrahydrofuran (THF) and water in the presence of heteropolyacids (HPA), without the hydrolysis step. The reaction is carried out by mixing two liquid phases: the THF phase and a heteropolyacid catalyst phase. In this reaction the molar ratio of water to a heteropolyacid (H 2 O/HPA) in the catalyst phase plays an important role in the THF polymerization activity and the molecular weight of PTMG. IR spectrometric studies revealed that THF is coordinated to a heteropolyanion through either a water molecule or a proton in the catalyst phase. The latter type of coordination bings about the activation of THF capable of initiating the ring‐opening polymerization even in the presence of water at a lower acid strength. The PTMG prepared by this method has a narrow molecular weight distribution (M̄ w /M̄ n = 1.5 or less) and a number average molecular weight of 500–2000 which are requisite for the production of polyurethane elastomers. A new polymerization mechanism named “Phase Transfer Polymerization” is proposed for elucidating a narrow molecular weight distribution.