Effect of Surface Modification on Strain Rate Sensitivity of Polypropylene/Muscovite Layered Silicate Composites Mohd Firdaus Omar 1* , Nur Suhaili Abd Wahab 1 , Hazizan Md Akil 2,3 , Zainal Arifin Ahmad 2 , Mohd Fadli Ahmad Rasyid 2 , N.Z. Noriman 1 1 School of Materials Engineering, Universiti Malaysia Perlis, Kompleks Pengajian Jejawi 2, 02600 Arau, Perlis 2 School of Material and Mineral Resource Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia. 3 Cluster of Polymer Composites (CPCs), Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia. Corresponding author: firdausomar@unimap.edu.my (Mohd Firdaus Bin Omar) +0604-9797933 (phone number) 006-9798178 (fax number) Key words: Ion exchange treatment; Strain rate sensitivity; Muscovite particles; Split Hopkinson pressure bar apparatus; Strain rates ABSTRACT Surface modification is one of the treatment methods that can be implemented to improve the strain rate sensitivity of composite materials. In this study, both untreated and treated polypropylene/muscovite layered silicate composites were tested under static and dynamic loading up to 1100 s -1 using the universal testing machine and the split Hopkinson pressure bar apparatus, respectively. Muscovite particles were treated with lithium nitrate and cetyltrimethylammonium bromide as a surfactant through ion exchange treatment. Results show that the treated polypropylene/muscovite specimens with fine state of dispersion level shows better rate of sensitivity as compared to untreated polypropylene/muscovite specimens under a wide range of strain rate investigated. Apart from that, the rate of sensitivity of both tested polypropylene/muscovite layered silicate composites also show great dependency on the strain rate sensitivity was steadily increased with increasing strain rate. Unfortunately, the thermal activation values show contrary trend. Introduction Layered silicates have been widely used as reinforcement materials or filler in the polymer composite because of their abundance, high strength, larges interfaces and achieving considerable reinforcement at very small filler loading. Among many different types of layered silicate, muscovite has become the most promising reinforcement than that of others conventional layered silicate with similar nature. This was due to its well-defined crystal structure, molecularly smooth surface, outstanding corona resistance, high aspect ratio and available in large amounts with relatively low cost 1 . For muscovite layered silicate composites, the factors that need to be Materials Science Forum Vol. 803 (2015) pp 343-347 © (2015) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/MSF.803.343 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 58.27.57.125-19/08/14,07:30:15)