Void morphology in polyethylene carbon black composites

Through the use of small angle neutron scattering (SANS), we have determined the size and quantity of voids incorporated during fabrication of polyethylene/carbon black composites. Analysis of such systems via X-ray scattering is difficult because of their three-phase nature, being composed of polymer matrix, filler, and any trapped voids. Through a combination of SANS on deuterated and protonated composites, however, the scattering contrast can be varied to reflect either a two or three phase morphology and the size and quantity of voids determined. The scattering analysis used to extract void morphology is based on the three-phase model of microcrack determination via small angle X-ray scattering (SAXS) developed by W. Wu (Polymer 1982, 23, 1907) as applied to particulate reinforced composites.