Effects of structural and processing parameters on the thermomechanical properties of polymer nanocomposites

abstract

English

The obstacle in transforming polymer nanocomposites into industrially viable materials lies in a current inability to directly control the organization of nanoparticles over multiple length scales on a reasonably short production time scale. We focused on discovering preparation protocols allowing rapid spatial organization of functional NPs over multiple length scales. We resolved the effect of various components such as polymer matrices, nanoparticles, and solvent, in which matrices and nanoparticles are blended. The key to organizing specific particles in a specific matrix is controlled by thermodynamic parameters such as interfacial interactions and interaction with a solvent used during the preparation. In the organization of particles of size about 15 nm, we moved from simple systems (individually dispersed particles, aggregates) to more complicated structures (percolation structures, compact narrow straight aggregates of micron size potentially capable of transmitting stresses). The polymer chain dynamics in the presence of particles may be accelerated (if there are repulsion forces between the polymer and particles) or slowed-down (attractive interactions). The dispersion of nanoparticles in the matrix at nanoscale affects the extent of the modified matrix representation - in the case of individually dispersed particles is maximalized active surface of particles and affect a substantial part of the matrix, whereas for aggregated particles the active surface is reduced. Therefore, the different structure of nanocomposites leads to different properties we investigated, especially glass transition temperature (activation energy of glass transition temperature), tensile creep, elastic and plateau moduli, reptation time or viscosity although nanocomposites are prepared from the same materials and have the same chemical composition. Achieved much better mechanical properties of our nanocomposites are inaccessible by conventional micromechanical models.

Polymer nanocomposites, nanosilica, self-assembly, thermo-mechanical properties.

ZÁRYBNICKÁ, K.; ONDREÁŠ, F.; JANČÁŘ, J.; LEPCIO, P.; ZBONČÁK, M.

25. 3. 2018

Stichting Materials Technology

Eindhoven, The Eindhoven

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