Morphological Properties of Polyethylene-Kevlar Composite Foams
Denis Rodrigue, Yaolin Zhang, Abdellatif Ait-Kadi
Laval University
Canada
Keywords: foam, composite, morphology
The morphological properties of linear high density polyethylene-Kevlar composite foams were investigated. The objective of this study was to understanding the effect of fibre (dimensions, interface properties and concentration) on the resulting morphology of composites foams produced via compression moulding.
The characterization of the foams was performed using microscopy in relation to the rheological properties of the unfoamed polymer and compound. Azodicarbonamide (ACA) was used as the chemical blowing agent at a concentration of 2 wt.% to produce composite foams having densities between 590 and 820 kg/m3. The cell sizes, cell density, and cell size distribution inside the composite foams were obtained by SEM microscopy using a JEOL 840A scanning electronic microscope, and quantitative image analysis was performed using Image-Pro Plus (Media Cybernetics). Finally, the shear viscosity of the unfoamed composites and matrices were measured using a rotational rheometer (Bohlin CVO).
The results obtained relating foam morphology to rheological properties of the polymer composition are discussed in terms of fibre content and fibre-polymer interface which affect the foaming process due to steric hindrance and higher resistance to bubble growth in the foaming process.