Prime

Type your tag names separated by a space and hit enter

Thermodynamic interactions in double-network hydrogels.

Abstract

Double-network hydrogels (DN-gels) prepared from the combination of a moderately cross-linked anionic polyelectrolyte (PE) and an uncross-linked linear polymer solution (NP) exhibit mechanical properties such as fracture toughness that are intriguingly superior to that of their individual constituents. The scheme of double-network preparation, however, is not equally successful for all polyelectrolyte/neutral polymer pairs. A successful example is the combination of poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS) cross-linked network and linear polyacrylamide (PAAm), which results in DN-gels with fracture strength under compression approaching that of articular cartilage ( approximately 20 MPa). Small-angle neutron scattering was used to determine the thermodynamic interaction parameters for PAMPS and PAAm in water as a first step to elucidate the molecular origin responsible for this superior property. Measurements on PAMPS/PAAm DN-gels and their solution blend counterparts indicate that the two polymers interact favorably with each other while in water. This favorable PAMPS/PAAm interaction given by the condition chi(PE-NP) < chi(PE-water) <chi(NP-water), where chi is the Flory-Huggins interaction parameter, is consistent with some of the salient features of the DN structure revealed by SANS, and it may also contribute to the ultimate mechanical properties of DN-gels.

Links

  • Publisher Full Text
  • Authors+Show Affiliations

    ,

    Polymers Division, National Institute of Standards and Technology, Gaithersburg Maryland, USA.

    , , , ,

    Source

    The journal of physical chemistry. B 112:13 2008 Apr 03 pg 3903-9

    MeSH

    Acrylic Resins
    Anions
    Electrolytes
    Gels
    Hydrogels
    Polymers
    Scattering, Small Angle
    Solutions
    Sulfonic Acids
    Thermodynamics
    Water

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't
    Research Support, U.S. Gov't, Non-P.H.S.

    Language

    eng

    PubMed ID

    18331022