title: Synthesis and properties of pH and temperature sensitive P(NIPAAm-co-DMAEMA) hydrogels.
abstract: In order to investigate the influence of the continuous alkylamide sequence having pH sensitive unit on the temperature sensitivity of poly(N-isopropylacrylamide) (PNIPAAm)-based hydrogel, a monomer, N-(2-(dimethylamino) ethyl)-methacrylamide (DMAEMA), having an ethylamide group as well as an aliphatic tertiary amino group, was designed and synthesized. Hydrogels based on NIPAAm and DMAEMA were prepared via free radical polymerization. The resulted P(NIPAAm-co-DMAEMA) hydrogels were characterized in terms of maximum swelling ratio, swelling kinetics, temperature response kinetics, and effect of pH. The data obtained show that the novel hydrogels have the strong desire to respond to external temperature and pH stimuli. Importantly, because the P(NIPAAm-co-DMAEMA) hydrogels have the continuous alkylamide sequence containing isopropylamide pendant groups from PNIPAAm and ethylamide pendant groups from PDMAEMA, the incorporation of DMAEMA moiety not only provides the pH sensitivity, but also maintains the thermal properties of P(NIPAAm-co-DMAEMA) hydrogels, even as the molar percentage of DMAEMA moiety reaches 14 mol%.
authors.affiliation: Department of Pharmacy, the Renmin Hospital of Wuhan University, Wuhan 430060, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Xiao-Ding
authors.initials: XD
authors.lastname: Xu
authors.forename: Zong-Chun
authors.initials: ZC
authors.lastname: Wang
authors.forename: Si-Xue
authors.initials: SX
authors.lastname: Cheng
authors.forename: Xian-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-Xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis* / Q000737:chemistry; D000180:Acrylic Resins; D006358:Hot Temperature; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008689:Methacrylates / Q000138:chemical synthesis* / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D020100:Hydrogels; D008689:Methacrylates; D011108:Polymers; C052970:poly-N-isopropylacrylamide; C049840:2-(dimethylamino)ethyl methacrylate