title: Synthesis of thermo-responsive polymers with both tunable UCST and LCST.
abstract: New water-soluble block copolymers of 2-(2-methoxyethoxy)ethyl methacrylate (MEO(2) MA), oligo(ethylene glycol) methacrylate (OEGMA), and N-(3-(dimethylamino) propyl) methacrylamide (DMAPMA) (poly(OEGMA-co-MEO(2) MA)-b-poly(DMAPMA)) were prepared via sequential reversible addition-fragmentation chain transfer (RAFT) polymerization. Selective quaternization of poly(DMAPMA) block gives poly(OEGMA-co-MEO(2) MA)-b-poly((3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]ammoniopropane sulfonate)-co-N-(3-(dimethylamino) propyl) methacrylamide), such block copolymer exhibits double thermo-responsive behavior in water, poly(MEO(2) MA-co-OEGMA) block shows a lower critical solution temperature (LCST), and poly((3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]ammoniopropane sulfonate)-co-N-(3-(dimethylamino) propyl) methacrylamide) block shows a upper critical solution temperature (UCST). Both of LCST and UCST can be controlled: LCST could be tuned by the fraction of OEGMA units in poly(OEGMA-co-MEO(2) MA), and UCST was found to be dependent on the degree of quaternization (DQ).
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China.
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Tian
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Yan
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Gu
authors.forename: Ye-Zi
authors.initials: YZ
authors.lastname: You
authors.forename: Xue-Si
authors.initials: XS
authors.lastname: Chen
mesh_terms: D008689:Methacrylates / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
chemical_list: D008689:Methacrylates; D011108:Polymers; C539356:2-(2-methoxyethoxy)ethyl methacrylate; C004919:ethylene dimethacrylate