Moisture Absorption Behavior of Palm/Polypropylene Composites in Distilled Water and Sea Water Ramazan Kahraman Basel Abu-Sharkh Chemical Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia The objective of this study was to investigate the moisture absorption behavior of uncompatibilized and compatibilized palm fiber=polypropylene composites in dis- tilled water and sea water. The amount of moisture absorbed at saturation by poly- propylene during immersion in both environments increased significantly by introduction of palm fiber in the polymer and this amount was not affected by use of a coupling agent=compatibilizer (Epolene E-43). On the other hand, incor- poration of the compatibilizer Epolene E-43 in the composites increased moisture diffusion rate significantly. Moisture diffusivity values obtained in distilled water and sea water were similar in the case of palm=PP composite specimens without any compatibilizer. However, the moisture diffusion rate was faster in distilled water than that in sea water in the case of using compatibilizer Epolene E-43 in the palm=PP composite. Keywords: cellulosic fiber, composite, diffusion, diffusivity, palm, polypropylene, sea, water, wood INTRODUCTION Composite materials based on fibers of natural polymers, such as wood cellulose fibers, and thermoplastics recently attracted much attention due to the remarkable environmental and economical advantages. The advantages of using cellulosic fibers as reinforcements in thermoplastics Received 7 March 2006; in final form 27 March 2006. The authors gratefully acknowledge the assistance of King Fahd University of Petroleum & Minerals in the performance of this work. Address correspondence to Dr. Ramazan Kahraman, Chemical Engineering Depart- ment, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia. E-mail: kahraman@kfupm.edu.sa International Journal of Polymeric Materials, 56:43–53, 2007 Copyright # Taylor & Francis Group, LLC ISSN: 0091-4037 print=1563-5333 online DOI: 10.1080/00914030600701926 43