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Hybrid Polymerization of Vinyl and Hetero‐Ring Groups of Glycidyl Methacrylate Resulting in Thermoresponsive Hyperbranched Polymers Displaying a Wide Range of Lower Critical Solution Temperatures
Hybrid polymerization of glycidyl methacrylate (GMA) with potassium hydride (KH) and various oligo(ethylene glycol)s as the initiating system, in which both vinyl polymerization and ring‐opening polymerization occur simultaneously, generates hyperbranched poly(ether‐ester)s. The reaction process has...
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Published in: | Chemistry : a European journal 2009-08, Vol.15 (31), p.7593-7600 |
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Main Authors: | , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Hybrid polymerization of glycidyl methacrylate (GMA) with potassium hydride (KH) and various oligo(ethylene glycol)s as the initiating system, in which both vinyl polymerization and ring‐opening polymerization occur simultaneously, generates hyperbranched poly(ether‐ester)s. The reaction process has been followed by an in situ nuclear magnetic resonance technique. The experimental results indicate that both the vinyl and epoxy groups of GMA undergo polymerization, with the reactivity of the latter being much higher than that of the former. Interestingly, the resulting hyperbranched polymers exhibit a sharp phase transition in water at the lower critical solution temperature (LCST). Significantly, the LCST values can be accurately controlled from 0 to 100 °C by changing the hydrophilic/hydrophobic balance of GMA and various oligo(ethylene glycol)s or by modification of the precursor polymer through acetylation. This novel stimuli‐responsive hyperbranched polymer is a promising candidate for a new generation of commercially viable thermoresponsive polymers following on from the widely used poly(N‐isopropylacrylamide) (PNIPAM).
Temperature‐specific phase separation: Thermoresponsive hyperbranched polymers have been synthesized by hybrid polymerization of glycidyl methacrylate and oligo(ethylene glycol)s. Reversible abrupt phase separation at the LCST renders an aqueous solution of such a polymer opaque (see photographs, sjtu = Shanghai Jiao Tong University) by changing the hydrophilic/hydrophobic balance. |
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ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/chem.200900345 |