ABSTRACT Polypropylene composites of snail shell powder were prepared at filler contents, 0 to 40 wt%. The particle sizes of the snail shell powder investigated were 0.150, 0.30, and 0.42 µm. Talc, of particle size, 0.150 µm was used as the reference filler. The polypropylene composites were prepared in an injection moulding machine and the resulting composites were extruded as sheets. Some mechanical and end-use properties of the prepared composites were determined. Results showed that the snail shell powder improved the tensile modulus, flexural strength, and impact strength of polypropylene and these properties increased with increases in the filler content and decreases in the filler particle size. The elongation at break of the composites was however observed to decrease with increases in the filler content, and particle size. The elongation at break of talc filled polypropylene was zero, an indication of the brittle nature of polypropylene composites of talc. The hardness, water sorption (24-hr) and specific gravity of the composites were found to increase with increases in the filler content, and decreases in the filler particle size. The level of water absorbed by snail shell powder composites of polypropylene is considerably higher than that of talc filled polypropylene. The flame retardant properties of the prepared composites were however found to decrease with increases in the filler content, and particle size. Generally, snail shell powder was found to show greater property improvement over talc in the prepared composites.
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nullG. Onuegbu and I. Igwe, "The Effects of Filler Contents and Particle Sizes on the Mechanical and End-Use Properties of Snail Shell Powder Filled Polypropylene," Materials Sciences and Applications, Vol. 2 No. 7, 2011, pp. 810-816. doi: 10.4236/msa.2011.27110.
 B. English, P. Chow and D. S. Bajwaz, “Processing Composites,” CRC Press, New York, 1997.
 K. Oksman and J. F. Selin, “Plastics and Composites from Polylactic Acid,” Kluwer Academic Press, Berlin, 2004.
 A. K. Bledzki and J. Gassan, “Composite Reinforced with Cellulose-based Fibres,” Progress in Polymer Science, Vol. 24, No. 5, 1999, pp. 221-274.
 D. Plackett, L. A. Logstrup, P. W. Batsberg and L. Nielsen, “Biodegradable Composites based on 1-Polylactide and Jute Fibres,” Composites Science and Technology, Vol. 63, No. 9, 2003, pp. 1287-1296.
 L. Sun, M. Xiao, P. Xiao, J. Song, W. Wang, Y. Zhang and K. Gong, “Electrical Properties of Metal Filled Polypropylene Composite,” Society of Plastics Engineers, Annual Technical Conference, 1986, pp. 2230-2234.
 A. R. Sanadi, D. F. Caulfield, R. E. Jacobson and R. M. Rowell, “In: Kenaf properties, Processing and Products,” Mississipi State University, Ag and Bio Engineering, Chapter 32, 1999, pp. 381-392.
 H. S. Katz and J. V. Milewski, “Handbook of Fillers for Plastic,” Van Nostrand Reinhold, New York, 1987.
 M. Gahleitner, B. Kretzschmar, D. Pospiech, E. Ingolic, E. Reichelt N. Reichelt and K. Bernreitner, “Morphology and Mechanical Properties of Polypropylene/Polyamide 6 Nanocomposites Prepared by a two-step Melt Compounding Process,” Journal of Applied Polymer Science, Vol. 100, No. 1, 2006, pp. 283-291.
 S. K. Najafi, E. Hamidinia and M. Tajvidi, “Mechanical Properties of Composites from Sawdust and Recycled Plastics,” Journal of Applied Polymer Science, Vol. 100, 2006, pp. 3641-3645. doi:10.1002/app.23159
 J. Moran, V. Alvarex, R. Petrucci, J. Kenny and A. Vazquez, “Mechanical Properties of Polypropylene Composites Based on Natural Fibres subjected to Multiple Extrusion Cycles,” Journal of Applied Polymer Science, Vol. 103, No. 1, 2007, pp. 227-237.
 P. Mutje, M. E. Vallejos, J. Girones, F. Vilaseca, A. Lopez, J. P. Lopez and J. A. Mendez, “Effect of Maleated Polypropylene as Coupling Agent for Propylene Composites Reinforced with Hemp Strands,” Journal of Applied Polymer Science, Vol. 102, No. 1, 2006, pp. 833-840.
 J. L. Leblanc, C. R. G. Furtado, M. C. A. M. Leite, L. L. Y. Visconte and M. H. Ishizaki, “Investigating Polypropylene-Green Coconut Fibre Composites in the Molten and Solid States through Various Techniques,” Journal of Applied Polymer Science, Vol. 102, No. 2, 2006, pp. 1922-1936. doi:10.1002/app.24239
 W. W. Yi, Z. X. Fei, W. G. Guan and C. J. Feng, “Preparation and Properties of Polypropylene Filled with Organo-Montmorillonite Nanocomposites,” Journal of Applied Polymer Science, Vol. 100, No. 4, 2006, pp. 2875-
 Y. Fan, J. Lou and D. M. Shinozaki, “Microstructure Dependent Properties of Polypropylene-Clay Nanocomposites,” Applied Polymer science, Vol, 103, No. 1, 2007, pp. 204-210.
 X. Chen, J. Yu and S. Guo, “Structure and Properties of Polypropylene Composites Filled with Magnesium Hydrixide,” Applied Polymer science, Vol. 102, No. 5, 2006, pp. 4943-4951.
 I. O. Igwe, “Studies on the Properties of Polypropylene filled with Agricultural and Domestic Wastes,” Journal of Research in Engineering, Vol. 4, No. 2, 2007, pp. 8-12.
 D. M. Bigg, “Mechanical Properties of Particulate filled Polymers,” Polymer Composites, Vol. 8, No. 2, 1987, pp. 115-122. doi:10.1002/pc.750080208
 M. Y. A. Fuad, Z. Ismail, Z. A. M. Ishak and A. K. M Omar, “Application of Rice Husk Ash as Fillers in Polypropylene: Effect of Titanate, Zirconate and Silane Coupling Agents,” European Polymer Journal, Vol. 31, No. 9, 1995, pp. 885-893. doi:10.1016/0014-3057(95)00041-0
 S. N. Das, T. K. Khastgir and D. K. Chakraborty, “Effect of Filler Blend Composition on the Electrical and Mechanical Properties of Conductive AVE Composite,” Project Euclid, Vol. 8, 2002, pp. 457-634.
 Y. E. Embu, C. C. Briggs and R. J. Heath, “The Effect of Mica Reinforcement on the Mechanical Properties of Polypropylene,” Nigerian Journal of Polymer Science, Vol. 1, No. 1, 2000, pp. 40-45.
 H. Ismail, H. D. Rozman, R. M. Jaffri and Z. A. Mohd Ishak, “Oil Palm Wood Flour Reinforced Epoxidized Natural Rubber Composites: The Effect of Filler Content and Size,” European Polymer Journal, Vol. 33, No. 10-12, 1997, pp. 1627-1632.
 B. V. Kokta, R. G. Raj and C. Daneault, “Use of Wood Flour as Filler in Polypropylene: Studies on Mechanical Properties,” Polymer Plastic Technology and Engineering,
Vol. 28, 1989, p. 247.
 R. M. Rowell, A. Sanadi, R. Jacobson and D. Caulfield, “Properties of Kenalf/Polypropylene Composites,” Mis- sissipi State University, Ag and Bio Engineering, Chapter 32, 1999, pp. 381-392.
 A. S. M. Salenddin and K. M. Wilbur, “Chemical Composition of Snail Shell,” Journal of Zoology, Vol. 47, 1969, pp. 51-55.