The pressure-volume-temperature (PVT) behavior and glass transition behavior of a 10 wt % silica nanoparticle-filled polystyrene (PS) nanocomposite sample are measured using a custom-built pressurizable dilatometer. The PVT data are fitted to the Tait equation in both liquid and glassy states; the coefficient of thermal expansion α, bulk modulus K, and thermal pressure coefficient γ are examined as a function of pressure and compared to the values of neat PS. The glass transition temperature (Tg) is reported as a function of pressure, and the limiting fictive temperature (Tf′) from calorimetric measurements is reported as a function of cooling rate. Comparison with data for neat PS indicates that the nanocomposite has a slightly higher Tg at elevated pressures, higher bulk moduli at all pressures studied, and its relaxation dynamics are more sensitive to volume. The results for the glassy γ values suggest that thermal residual stresses would not be reduced for the nanocomposite sample studied.
|Number of pages||8|
|Journal||Journal of Polymer Science, Part B: Polymer Physics|
|State||Published - Aug 15 2015|
- bulk modulus
- glass transition
- pressure-volume-temperature behavior
- thermal properties