Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Patent
1984-06-05
1985-04-09
Evans, J. E.
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C07C 4114
Patent
active
045103330
ABSTRACT:
In the preparation of poly(tetramethylene ether) glycol by the polymerization of tetrahydrofuran (THF) using a cationic initiator, molecular weight distribution (MWD) can be held within narrow limits by bringing the THF and the initiator together in a mol ratio such that the degree of polymerization will be at about a minimum and at a temperature which will promote about a maximum number of tertiary oxonium ions, then quickly cooling the reaction mass to -25.degree. C. to +25.degree. C., and then adding enough THF to complete the polymerization. When the desired molecular weight and MWD have been reached, the polymerization is quenched and the polymer isolated.
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Rosenberg et al., "Journal of Polymer Science", Part C, No. 16, pp. 1917-1929, (1967).
"Synthesis of Narrow Distribution Polytetrahydrofuran," Croucher and Wetton, Polymer, 1976, vol. 17, Mar.
"Preparation of Narrow-Molecular-Weight-Distribution Poly(tetrahydrofuran)," Fujimoto, Kawahashi, Nagasawa and Takahashi, Polymer J., vol. 11, No. 3, 1979.
E. I. Du Pont de Nemours and Company
Evans J. E.
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