Keggin-Type Heteropolyacid for Ring-Opening Polymerization of Cyclohexene Oxide: Molecular Weight Control
Polymerization of 1,2-cyclohexene oxide (CHO) in dichloromethane was catalyzed by 12-tungstophosphoric acid (H3PW12O40·13H2O) as a super solid acid. The effect of polymerization parameters such as reaction time, temperature, and...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Hindawi Limited
2015-01-01
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| Series: | International Journal of Polymer Science |
| Online Access: | http://dx.doi.org/10.1155/2015/826512 |
| Summary: | Polymerization of 1,2-cyclohexene oxide (CHO) in
dichloromethane was catalyzed by 12-tungstophosphoric
acid
(H3PW12O40·13H2O)
as a super solid acid. The effect of polymerization
parameters such as reaction time, temperature, and
catalyst amount was investigated. The effect of acetic
anhydride as a ring-opening agent was also
investigated. The resulting poly(1,2-cyclohexene oxide) (PCHO) was characterized by Fourier transform
infrared (FTIR), nuclear magnetic resonance
spectroscopy (1HNMR), gel-permeation
chromatography (GPC), and differential scanning
calorimetry (DSC). It has been found that the PCHO
prepared over
H3PW12O40·13H2O
has a stereoregularity higher than that prepared over
clay and Aluminium alkoxide catalysts. The Tg value obtained is due to the
microstructure but not to molecular weight. The
yield and the molecular weight of the polymer
depend strongly on the reaction conditions.
Molecular weights can be readily controlled by
changing reaction temperature, reaction time, and
catalyst amount. Contrary to most polymerization
reactions, the molecular weight increases with the
temperature increase. Addition of acetic anhydride
to the reaction medium increased the yield
threefold. |
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| ISSN: | 1687-9422 1687-9430 |