Get access

Rheology and phase behavior of thermo-reversible pentablock terpolymer hydrogel

Authors

  • Yufeng Wu,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Renmin South Avenue, Chengdu, People's Republic of China
    2. College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, People's Republic of China
    Search for more papers by this author
  • Dingwei Zhu,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Renmin South Avenue, Chengdu, People's Republic of China
    2. College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, People's Republic of China
    Search for more papers by this author
  • Zanru Guo,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Renmin South Avenue, Chengdu, People's Republic of China
    2. College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, People's Republic of China
    Search for more papers by this author
  • Yujun Feng

    Corresponding author
    1. State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, People's Republic of China
    • Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Renmin South Avenue, Chengdu, People's Republic of China
    Search for more papers by this author

Correspondence to: Y. Feng (Email: yjfeng@cioc.ac.cn)

ABSTRACT

Thermo-reversible phase behaviors and rheological properties of a pentablock terpolymer solution, poly(N-isopropylacrylamide)-b-poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide)-b-poly(N-isopropylacrylamide) (PNIPAM150-PEO136-PPO45-PEO136-PNIPAM150), are investigated in comparison with its precursor, PEO136-PPO45-PEO136 (F108). It is found that the critical gelation concentration of the terpolymer solution is only about 11 wt %, which is significantly lower than that of F108 solution (∼22 wt %). The 11 wt % terpolymer solution displays higher viscosity, stronger gel strength, and fast thermo-responsive behavior compared with the 22 wt % F108 solution. The 11 wt % terpolymer solution shows a typical Newtonian fluid behavior at 30 °C due to the presence of individual spherical micelles, and presents an elastic gel property at 41 °C because of the formation of the close-packed micelle aggregates. Cryogenic transmission electron microscopy (cryo-TEM) and variable-temperature 1H NMR results demonstrate that the sol–gel phase transition mechanism is mainly related to the hydrophilic/hydrophobic transition of PPO and PNIPAM groups by external temperature stimulus. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1335–1342

Get access to the full text of this article

Ancillary