Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

Marc Meijerink, Frank van Mastrigt, Linda E. Franken, Marc C. A. Stuart, Francesco Picchioni, Patrizio Raffa*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)
316 Downloads (Pure)

Abstract

Well-defined amphiphilic triblock poly(sodium methacrylate)-polystyrene-poly(sodium methacrylate) (PMAA-b-PS-b-PMAA) copolymers characterized by a different length of either the hydrophilic or the hydrophobic block have been synthesized by ATRP. In solution the micelle-like aggregates consist of a collapsed PS core surrounded by stretched charged PMAA chains. The micelles are kinetically 'frozen' and as a consequence the triblock copolymers do not show a significant surface activity. The hydrophilic block length has a major influence on the rheology, the shortest PMAA blocks yielding the strongest gels (at the same total weight concentration). The hydrophobic block length has only a minor influence until a certain threshold, below which the hydrophobic interactions are too weak resulting in weak gels. A mathematical model is used to describe the micelle radius and the results were in good agreement with the experimentally found radius in transmission electron microscopy. The influences of the ionic strength, pH and temperature on the rheology has also been investigated, showing the potential of these polymers as smart hydrogels. The change in conformation of the hydrophilic corona from the collapsed state to the stretched state by changing the pH was quantified with zeta-potential measurements. To the best of our knowledge, this is the first systematic investigation of this kind of triblock copolymers in terms of their rheological behavior in water.

Original languageEnglish
Pages (from-to)1641-1658
Number of pages18
JournalPure and Applied Chemistry
Volume89
Issue number11
DOIs
Publication statusPublished - 26-Oct-2017

Keywords

  • amphiphilic block copolymers
  • ATRP
  • cryo-electron microscopy
  • POC-16
  • rheology
  • smart hydrogels
  • zeta potential
  • AMPHIPHILIC BLOCK-COPOLYMERS
  • CONTROLLED/LIVING RADICAL POLYMERIZATION
  • ENHANCED OIL-RECOVERY
  • EMULSION POLYMERIZATION
  • AQUEOUS-SOLUTION
  • DIBLOCK COPOLYMERS
  • MICELLES
  • MICELLIZATION
  • POLYMERS
  • BEHAVIOR

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