Table of Contents
ISRN Polymer Science
Volume 2014, Article ID 571641, 7 pages
Research Article

Thermal Expansion Behavior of Nonoriented Polypropylene/Clay Composites

1Petrochemicals Research Institute, King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Saudi Arabia
2Mechanical Engineering Department, Izmir Institute of Technology, Gulbahce Koyu, 35430 Urla, Turkey

Received 11 November 2013; Accepted 24 December 2013; Published 3 February 2014

Academic Editors: A. V. Popov and A. Voronov

Copyright © 2014 Fares D. Alsewailem and Metin Tanoglu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Linear thermal expansion coefficient (LTEC) was measured for compression molding samples of polypropylene (PP)/clay composites with clay loading of 0 to 7 wt%. Composites were prepared by internal batch mixer and specimens were prepared by compression molding. These processing methods are not anticipated to have a preference for orientation; therefore effect of anisotropy was minimal. The LTEC was measured along three different faces of the compression molding sheets, parallel to compression direction S1 and perpendicular to compression directions S2 and S3. The LTEC for neat PP measured by current research,  mm/mm/°C, was not found to be altered by direction of the measurements. Similar behavior was observed with composites having very moderate clay content, that is, 5 wt%. An interesting finding by current study was that incorporating clay particles into the PP matrix led to better shrinkage or contraction behavior of the samples prepared by compression molding.