کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5191918 | 1381243 | 2005 | 9 صفحه PDF | دانلود رایگان |
The electrostatic self-assembly of thermally responsive copolymers of N-isopropylacrylamide (NIPAM) containing up to 10Â mol% of the sulfobetaine monomer 3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]ammoniopropane sulfonate) (SPP) and poly(ethylene oxide) modified with terminal cationic or anionic groups (IMPEO) was studied in methanol and aqueous solutions by static light scattering, turbidimetry, viscometry, and rheological measurements. The formation of graft-like complexes at stoichiometric dipole-ion ratio and their self-association was detected in the dilute and semidilute regime at temperatures below and above the lower critical solution temperature (LCST). The ability of the graft-like complexes to associate below the LCST depended on the sulfobetaine content of the copolymers, the functionality of IMPEO, and the polymer concentration. The effect of the IMPEO terminal group on the solution behavior of the graft-like complexes was less pronounced. With increasing temperature their semidilute aqueous solutions form gels, stable over a wide temperature range.
Journal: Polymer - Volume 46, Issue 7, 10 March 2005, Pages 2059-2067