Abstract
Natural vermiculite was modified by cation exchange with long-chain quaternary alkylammonium salts and then dispersed in polyether-based polyols with different structures and ethylene oxide/propylene oxide ratios. The dispersions were evaluated by X-ray scattering and rheology. In all polyol dispersions tested, polyols were intercalated into the vermiculite interlayers. Also, significant shear thinning behavior was observed. A large interlayer spacing of ∼90 Å was achieved in one polyol suitable for polyurethane elastomer synthesis. In polyurethane made with this polyol, clay platelets were extensively intercalated or exfoliated. The composites showed a >270% increase in tensile modulus, >60% increase in tensile strength, and a 30% reduction in N 2 permeability with a loading of 5.3 wt % clay in polyurethane. Differential scanning calorimetry and dynamic mechanical analysis revealed that the nanoclay interacts with the polyurethane hard segments.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3709-3717 |
| Number of pages | 9 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 3 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 28 2011 |
Keywords
- barrier properties
- elastomer
- organoclay
- polymer-clay nanocomposites
- polyurethane
- vermiculite