(763d) Output Particle Structure and Morphology Development of Polymer Nanocomposites Processed via Solid-State Pulverization Techniques

Industrial and scientific interest in commercial-scale fabrication of polymer nanocomposites has led to the recent development of continuous solid-state processing techniques, such as solid-state shear pulverization (SSSP) [1] and solid-state/ melt extrusion (SSME) [2].  These methods are based on a twin screw extruder setup, but rely on the mechanism of in situ, low-temperature mechanical shear and compression of materials, which in turn provides high degrees of exfoliation (separation) and dispersion (distribution) of nanofillers within the polymer matrix.  

The nanoscale morphology of composite products are often characterized by electron microscopy and X-ray diffraction techniques, and generally well understood.  However, there is little understanding of how the filler particles transform through the processing, in particular, how the dimensions change from macro and micro-scale to nano-scale.  In addition, the correlation between the pulverized particle sizes to the nano-scale filler morphology within those particles has not been reported. 

In this paper, a systematic processing-particle structure study of model polymer nanocomposites using SSSP and SSME techniques is introduced.  The microstructure of the powder (SSSP) and pellet (SSME) outputs are compared using optical and electron microscopy.  In addition, the filler surface characteristics will be quantitatively examined via BET surface area analysis.  A clearer understanding of the nanocomposite morphology development is expected to lead to a better control of the structure-property relationships in these materials.  

[1] K. Wakabayashi, C. Pierre, D. A. Dikin, R. S. Ruoff, T. Ramanathan, L. C. Brinson, and J. M. Torkelson, Macromolecules, 41, 1905 (2008).
[2] A. M. Whittington, S. M. Brouse, M. A. Malusis, and K. Wakabayashi, Advances in Polymer Technology, 32, 21334 (2013).