16 TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS DEVELOPMENT OF NATURAL FIBER COMPOSITE CONSTRUCTION WITH IMPROVED TENSILE PROPERTIES Chinmaya Dandekar, P. K. Mallick Center for Lightweighting Automotive Materials and Processing University of Michigan-Dearborn Dearborn, MI 48128, USA Keywords: Natural Fiber, Polypropylene, Tensile Modulus, Tensile Strength, Water Absorption Abstract The use of natural fiber composites is increasing in the automotive industry as well as in many other industries. In this study, we consider combining a natural fiber/polypropylene composite with other polypropylene based composites with the objective of improving their tensile modulus and strength. Compression molded plates were prepared with various combinations of these materials and at different molding temperatures. Tensile properties of the combined materials were determined and are reported in this paper. In addition, water absorption data are also reported. 1 Introduction Natural fiber composites have great potential in many automotive applications [1, 2] for the following reasons [3]: (1) Natural fibers are environment-friendly, meaning that they are agricultural products, they are biodegradable, and compared to glass and carbon fibers, the energy consumption to produce them is very small. (2) The mass density of natural fibers is in the range of 1.2 to 1.5 g/cm 3 , which is much lower than both glass and carbon fibers. (3) The modulus-to-density ratio of many natural fibers is higher than that of glass fibers. (4) Natural fiber composites can provide higher acoustic damping than glass or carbon fiber composites, and therefore, they are more suitable for noise attenuation. (5) The price of natural fibers is less than that of glass fibers and much less than that of carbon fibers. Since natural fibers have many advantages over the conventional fibers, a large number of research has been done to incorporate them in both thermoplastic and thermoset polymers. Several applications of natural fiber composites have also been developed, but most of them are for non- structural applications. One reason for this is that natural fiber composites have relatively low modulus and strength compared to glass and carbon fiber composites. In this paper, we report a preliminary study to develop natural fiber composite sandwich constructions with the goal of achieving higher modulus and higher strength . 2 Experimental 2.1 Materials The materials used in this study were as follows: (1)Natural fiber mats containing 50% jute fibers and 50% polypropylene fibers, designated here as NL, NF and NH for low density, low density with an additional coating of polypropylene, and high density, respectively. Both NL and NF mats were 10 mm thick and the NH mat was 2.6 mm thick. All three natural fiber mats were supplied by Flexform, Inc. (2)Geotextile woven fabrics containing polypropylene filament (Propex 2033, designated here as P and Propex 2044, designated here as Q). The geotextile fabrics were 0.93 mm thick and were supplied by Propex Fabrics, Inc. 1