%0 Journal Article
%T The Influence of Fiber Length and Concentration on the Physical Properties of Wheat Husk Fibers Rubber Composites
%A Maged S. Sobhy
%A M. T. Tammam
%J International Journal of Polymer Science
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/528173
%X Ethylene-propylene-diene terpolymer (EPDM)/wheat husk fibers (WHFs) composites were prepared using a laboratory size two-roll mill. Cure characteristics and some physical properties such as swelling, mechanical, and thermal properties of the vulcanizates were studied. The adhesion status between the WHF and rubber matrix is lacked in general, but it started to reinforce the matrix at higher WHF contents where a higher restriction to molecular motion of the macromolecules with uniformed stress distribution of the fibers is produced. From the TGA analysis, a thermally stable property is exhibited, which in turn partially enhanced the reinforcement of the WHF-EPDM composites due to the natural adhesion during vulcanization. 1. Introduction Natural fibers are subdivided based on their origins, coming from plants, animals, or minerals. Natural Plant-fibers are grouped into four types: seed hairs (cotton, kapok), bast-fibers (flax, hemp, jute, ramie), leaf-fibers (sisal, henequen, coir, abaca), and wood flour (wheat husk, rice husk) [1¨C5]. It is well known that wheat husk fibers were employed in Egypt [1] for a very long time ago for buildings as construction materials mixed with clay. Generally, the different types of natural fibers are used to reinforce plastics (thermosets as well as thermoplastics) and reach the mechanical properties of glass-fiber composites, and they are already applied, for example, in automobile and furniture industries due to their relative high strength and stiffness and low density [5]. Composites can be tailored to have the desired properties by incorporating particulate fillers into a polymer matrix to suit different applications [6]. For economic and environmental reasons [7, 8], there is an increasing use of polymer composites filled with lignocellulosic materials such as wood flour, rice husk, wheat husk, jute, and sisal [9¨C12]. The main disadvantage encountered during the incorporation of natural lignocellulosic materials into polymers is the lack of good interfacial adhesion between the two components, especially in the case of rubbers, due to the incompatibility of hydrophilic natural fibers that are to be used as reinforcement with hydrophobic polymer matrix [13, 14]. Furthermore, these composites are often associated with agglomeration as a result of insufficient dispersion, caused by the tendency of fillers to also form hydrogen bonds with each other during processing [13¨C15]. Moreover, the polar hydroxyl groups on the surface of the lignocellulosic materials have difficulty in forming a well-bonded interface with a
%U http://www.hindawi.com/journals/ijps/2010/528173/