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Thermosensitive copolymer synthesized by controlled living radical polymerization: Phase behavior of diblock copolymers of poly( N ‐isopropyl acrylamide) families
Author(s) -
Rwei SyangPeng,
Chuang YoYing,
Way TunFun,
Chiang WheYi
Publication year - 2016
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.43224
Subject(s) - lower critical solution temperature , nitroxide mediated radical polymerization , copolymer , polymerization , polymer chemistry , radical polymerization , materials science , dispersity , poly(n isopropylacrylamide) , polymer , acrylamide , aqueous solution , reversible addition−fragmentation chain transfer polymerization , chemistry , organic chemistry , composite material
In this study, we prepared a series of thermosensitive polymers with low polydispersity index (PDI) values by nitroxide‐mediated controlled radical polymerization (NMRP) with 2,2,6,6‐tetramethyl‐1‐piperdinyloxy nitroxide (TEMPO) as a stable nitroxide‐free radical. Poly( N ‐isopropyl acrylamide) (PNIPAAm)‐ block ‐poly( N ‐ tert ‐butyl acrylamide) (PNTBA) was successfully synthesized, first, through polymerization with N ‐isopropyl acrylamide to obtain the reactive polymer PNIPAAm‐TEMPO and, second, through polymerization by the addition of N ‐ tert ‐butyl acrylamide (NTBA). The added molar fraction of NTBA during the second polymerization was adjusted accordingly to obtain the final polymerization product, a thermosensitive polymer (PNIPAAm‐ block ‐PNTBA), which had a targeted lower critical solution temperature (LCST). The result shows that the synthesis method used in this study effectively controlled the formation of the polymer to obtain a low PDI. The thermosensitive block copolymer, PNIPAAm‐ b ‐PNTBA (molar ratio = 9:1), with LCSTs in the range 27.7–39.8°C, was obtained through controlled living radical polymerization with PNIPAAm–TEMPO. Specifically, the 5 wt % aqueous solution of PNIPAAm‐ b ‐PNTBA (molar ratio = 9:1) had an LCST of 37.4°C; this was close to body temperature, 37°C. The 5 wt % aqueous solution of PNIPAAm‐ b ‐PNTBA (molar ratio = 9:1) showed potential for use in biomedical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43224.