Acceleration of the initiation reaction of the cationic polymerization of tetrahydrofuran by stable cationic salts

Yamashita, Yuya; Matsui, Hajime; Hattori, Genjiro; Kozawa, Shigeyuki; Hirota, Mitsutomo

doi:10.1002/macp.1971.021420116

Cited by 7 publications

(5 citation statements)

References 5 publications

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“…The rate constants of the chain propagation ( k p ), on the assumption of Bednarek et al6 that each of the three protons of HPA starts a chain (i.e., that the concentration of active species [ P *] = 3[PW 12 ]), were found to be 3.78 × 10 −3 L mol −1 s −1 at 0°C and 1.98 × 10 −2 L mol −1 s −1 at 20°C, respectively. These values are in good agreement with the propagation rate constant of THF on ionic species 18, 21, 22…”

Section: Resultssupporting

confidence: 84%

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Zhang

1999

J. Appl. Polym. Sci.

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ABSTRACT:Tetrahydrofuran was polymerized using the heteropolyacid H 3 PW 12 O 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 ϳ 10°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 20°C were found to be 3.78 ϫ 10 Ϫ3 and 1.98 ϫ 10 Ϫ2 L mol Ϫ1 s Ϫ1 , respectively, which are close to the rate constant of chain propagation of tetrahydrofuran on ionic active species.

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Section: Resultssupporting

confidence: 84%

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Zhang

1999

J. Appl. Polym. Sci.

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“…These values are in good agreement with the propagation rate constant of THF on ionic species. 18,21,22 A detailed structure analysis of the copolyether based on the NMR spectrum and study of the polymerization mechanism of this system will be published in the future.…”

Section: Kinetics Studymentioning

confidence: 99%

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Zhang

1999

J. Appl. Polym. Sci.

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Tetrahydrofuran was polymerized using the heteropolyacid H 3 PW 12 O 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 ϳ 10°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 20°C were found to be 3.78 ϫ 10 Ϫ3 and 1.98 ϫ 10 Ϫ2 L mol Ϫ1 s Ϫ1 , respectively, which are close to the rate constant of chain propagation of tetrahydrofuran on ionic active species.

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“…It is difficult to predict both a moito pattern and a polymer structure in the image of PEO shown in Figure 16. Every other line spaced 12 A is enhanced and darker regions along the bright line are separated by 34 A, corresponding to a 8 x 4.3 A distance. Although the first effect can be produced by a bilayer construction of PEO-II layer on top of a PEO-III film, such a process can generate so many possibilities that a simple relation between the polymer structure and STM feature is lost.…”

Section: H-34mentioning

confidence: 99%

Structural study of polyethers on graphite by scanning tunneling microscopy. Polymerization-induced epitaxy

Sano¹,

Sasaki²,

Kunitake³

1992

Macromolecules

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The newly found phenomenon of polymerization-induced epitaxy can produce an ultrathin film of highly oriented polymer molecules on a solid surface. Poly(tetrahydrofuran), poly(oxacyclobutane), and polyethylene oxide) were epitaxially grown on the basal plane of graphite via in situ polymerization and their intraand interchain structures as well as epitaxial orientations were examined by scanning tunneling microscopy (STM). STM images indicated these polymer chains in a planar, all trans conformation commensurate with the graphite lattice. Different polymer lattices can be constructed by mutually shifting a chain with respect to the adjacent chain along the backbone direction, in units of the graphite hexagon. Most of the STM images can be explained by moir6 patterns generated through rotations of the polymer lattice on top of the graphite lattice. Such a pattern can only be observed if the film exists as a monolayer. Furthermore, we find that the present epitaxial growth process proceeds such that the two-dimensional array that constitutes a basic repeating pattern of a fringe, defined by the number of structural repeating units along the polymer backbone and the number of chains within a commensurate cell, becomes the first two smallest of all other possibilities, namely, one unit, one chain or seven units, seven chains.

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Acceleration of the initiation reaction of the cationic polymerization of tetrahydrofuran by stable cationic salts

Cited by 7 publications

References 5 publications

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Effective promotion of tetrahydrofuran polymerization initiated with heteropolyacid

Structural study of polyethers on graphite by scanning tunneling microscopy. Polymerization-induced epitaxy

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