Filler Exfoliation and Dispersion in Polymer-As Received Graphite Nanocomposites via Cryogenic Milling
Publication Date
2011
Description
Nanocomposites from polypropylene and unmodified, as-received graphite were fabricated via solid-state cryogenic milling (cryomilling) process. Filler contents up to 10 wt% were studied with cryomilling cycles and postcryomill melt mixing option as processing parameters. Scanning electron microscopy and X-ray diffraction of the cryomilled samples reveal that graphite filler particles are partially exfoliated into nanoplatelets, as well as fragmented in the lateral dimensions, when incorporated into the polymer matrix. Various physical performance, including polymer crystallization rate, thermomechanical response, oxygen barrier, and electrical conductivity, is closely dictated by the filler morphology. An increase in cryomilling time leads to a higher degree of exfoliation, resulting in an enhancement in stiffness/strength, thermal stability, and electrical conductivity. Postcryomill melt mixing disperses the partially exfoliated graphite nanoplatelets, raising stiffness/strength and thermal stability while reducing electrical conductivity and oxygen permeability. The percolation threshold occurs between 1 and 3 wt%, with an optimum content for most properties at ∼3 wt%
Journal
Polymer Engineering and Science
Volume
51
Issue
11
First Page
2273
Last Page
2281
Department
Chemical Engineering
Link to Published Version
https://4spepublications.onlinelibrary.wiley.com/doi/10.1002/pen.22001
DOI
doi.org/10.1002/pen.22001
Recommended Citation
Hubert, Paul J.. "Filler Exfoliation and Dispersion in Polymer-As Received Graphite Nanocomposites via Cryogenic Milling." (2011) : 2273-2281.