Effect of Processing Conditions on the Cellular Morphology of Polypropylene Foamed Films for Piezoelectric Applications
Effect of Processing Conditions on the Cellular Morphology of Polypropylene Foamed Films for Piezoelectric Applications Abolfazl Mohebbi1,2,3, Frej Mighri1,3, Abdellah Ajji1,4, and Denis Rodrigue1,2,3,* 1CREPEC,
Research Center for High Performance Polymer and Composite Systems Quebec Centre on Functional Materials 3Department of Chemical Engineering, Université Laval, Quebec, QC, G1V 0A6, Canada 4Department of Chemical Engineering, Polytechnique Montréal, C.P. 6079, Montreal, QC, H3C 3A7, Canada 2CQMF,
Received: 31 May 2016, Accepted: 1 July 2016
SUMMARY In this work, continuous extrusion-calendering was used to produce polypropylene (PP) foam films for piezoelectric applications. The setup is based on physical foaming using supercritical nitrogen (SC-N2) and calcium carbonate (CaCO3) as nucleating agent. In particular, the extrusion parameters (screw design, temperature profile, blowing agent and nucleating agent content) and post-extrusion conditions (calendaring temperature and speed) were optimized to achieve a specific stretched eye-like cellular structure with uniform cell size distribution. The morphology in both machine and transverse directions, as well as tensile properties were characterized. The results show that a cellular structure with a higher cell aspect ratio has a lower Young’s modulus, which is appropriate for piezoelectric cellular films. Generally, the developed foam morphology presents high potential for the production of ferroelectret PP films used in different piezoelectric applications. Keywords: Polypropylene, Foam, Physical blowing agent, Morphology, Extrusion. Piezoelectricity.
*Corresponding author e-mail:
[email protected] ©Smithers
Information Ltd. 2017
Cellular Polymers, Vol. 36, No. 1, 2017
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