• Title/Summary/Keyword: macroradical polymerization

Search Result 1, Processing Time 0.016 seconds

Synthesis and Characterization of Temperature and pH Sensitive Graft Copolymers Based on Pluronic (Pluronic을 기초로 한 온도와 pH에 민감한 그래프트 공중합체의 합성과 특성)

  • Oh, Yeon-Jeong;Lee, Gi-Baek;Park, Sung-Young
    • Polymer(Korea)
    • /
    • v.36 no.2
    • /
    • pp.223-228
    • /
    • 2012
  • Temperature and pH sensitive graft copolymers [Pluronic-$g$-poly(NIPAAm-$co$-MMA), Polymer A] and [Pluronic-$g$-poly( NIPAAm-$co$-MAA), Polymer C] were synthesized by macro radical graft polymerization with $N$-isopropylacrylamide (NIPAAM)/$N,N$-diethylaminoethylmethacrylate (DEAEMA) and $N$-isopropylacrylamide (NIPAAm)/methacrylic acid (MAA) based on Pluronic, respectively. The chemical structure and molecular weight of the graft copolymers was characterized by $^1H$ NMR and gel permeation chromatography. The aqueous solution properties of graft copolymers were measured using a UV-visible spectrophotometer, contact angle and dynamic light scattering equipment with different temperature and pH conditions. The obtained graft copolymers showed a very sensitive phase transition in response to temperature and pH in aqueous media which suggested that the amine group of DEAEMA segment and carboxylic group of MAA had a great influence on the lower critical solution temperatures (LCST) in Polymer A and C, respectively. The graft copolymers can be utilized for drug delivery system and molecular switching applications where responses to temperature and pH changes are relevant.