Compatibility/Dispersion in Multi-Hierarchical Polymer Nanocomposites*

Commercial polymer nanocomposites such as reinforced elastomers differ significantly from model nanocomposites. Successful commercial products display a complex multi-level hierarchical, nano- to macro-scale structure. We have studied these structures using TEM, small-angle x-ray scattering, and rheology. The multi-hierarchical structure in carbon black reinforced polybutadiene will be described as a function of processing conditions. The filler network in this compound displays a nanoscale aggregate network within nano-clusters that percolate on the micron scale. The nanoscale network develops due to thermodynamic incompatibility of carbon black and polybutadiene which is mitigated by the accumulated strain. The network clusters are limited in size due to incompatibility. On increasing concentration, percolation of these network clusters is observed in scattering, TEM and dynamic rheology. Through this work control over this complex multi-hierarchical structure will be achieved through manipulation of compatibility/incompatibily and processing history.

Y. Jin, et al. Polymer 129 (2017) 32
A. Mulderig, et al. Langmuir 33 (2017) 14029
A. Mulderig et al. Langmuir 33(2017) 14029
K. Rishi, et al., Macromolecules 51 (2018) 7893