Synthesis and characterization of well-defined PAA–PEG multi-responsive hydrogels by ATRP and click chemistry
writer：Zhou, C.; Qian, S.; Li, X.; Yao, F.; Forsythe, J. S.; Fu, G. D.
keywords：Click Chemistry, ATRP, Hydrogel
source：期刊
specific source：RSC Adv., 2014, 4, 54631–54640
Issue time：2014年
Multi-responsive poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) hydrogels with well-defined crosslinking structures were synthesized using atom transfer radical polymerization (ATRP) and coppercatalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) techniques. The well-defined PAA–PEG hydrogels with different degrees of crosslinking were produced from controlling the molecular weight of the PAA and PEG chains. The prepared multi-responsive hydrogels exhibit regular physical and mechanical properties by adjusting the pH and Ca2+ ion secondary crosslinking. With increasing pH, the swelling ratio of the well-defined multi-responsive PAA–PEG hydrogels increased remarkably. Furthermore, the well-defined PAA–PEG hydrogels with Ca2+ secondary crosslinking possessed a significantly higher crosslinking density as reflected by the lower swelling ratio, higher storage modulus, higher electrical conductivity and thermal stability. An in vitro cell viability assay also indicated that welldefined multi-responsive PAA–PEG hydrogels are biocompatible and have potential for implantable
biomaterials.