Selectivity of PEO-block-PPO Diblock Copolymers in the Microwave-Accelerated, Anionic Ring-Opening Polymerization of Propylene Oxide with PEG as Initiator
✍ Scribed by Muhammad Imran Malik; Bernd Trathnigg; C. Oliver Kappe
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 344 KB
- Volume
- 208
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Diblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) were synthesized by the anionic ring‐opening polymerization of propylene oxide (PO), with controlled microwave heating in sealed vessels. A detailed study was carried out to investigate the effects of different parameters on the formation of unwanted byproducts. Parameters that were considered include temperature; the concentration of NaH, monomer and hydroxy groups in the feed; and the polarity of the reaction medium. A continuous decrease of internal pressure during the sealed‐vessel experiment reflected the consumption of PO monomer and the completion of the reaction was confirmed by a drop of the internal pressure to zero when reactions were performed in bulk. The products were characterized by using different chromatographic techniques. A comparison of the reaction times and composition of the polymers prepared by microwave and conductive heating is given.
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