Reinforcing Effects of Natural Micro-Particles on the Dynamic Impact Behaviour of Hybrid Bio-Composites Made of Short Kevlar Fibers Reinforced Thermoplastic Composite Armor
Hybrid bio-composites are developed for use in protective armor through positive hybridization offered by reinforcement of high-density polyethylene (HDPE) with Kevlar short fibers and palm wood micro-fillers. The manufacturing process involved a combination of extrusion and compression molding techniques. The mechanical behavior of Kevlar fiber reinforced HDPE with and without palm wood filler additions are compared. The effect of the weight fraction of the added palm wood micro-fillers is also determined. The Young modulus was found to increase as the weight fraction of organic micro-particles increased. However, the flexural strength decreased with increasing weight fraction of added micro-fillers. The interfacial interactions between the components were investigated using scanning electron microscopy. The influence of the size, random alignment and distribution of the natural micro-particles was evaluated. Ballistic impact and dynamic shock loading tests were performed to determine the optimum proportion of Kevlar short fibers and organic micro-fillers needed to improve impact strength of the HDPE. These results indicate a positive hybridization by deposition of organic micro-fillers on the surface of short Kevlar fibers used in reinforcing the thermoplastic matrix leading to enhancement of the mechanical strength and dynamic impact behavior of these materials. Therefore, these hybrid bio-composites can be promising materials for different applications against high velocity impacts.
 M. Valente, F. Sarasini, F. Marra, J. Tirillò, and G. Pulci, “Hybrid recycled glass. fiber/wood flour thermoplastic composites: Manufacturing and mechanical characterization,” Composites Part A Applied Science Manuf., vol. 42, no. 6, pp. 649–657, 2011.
 G. Cantero, A. Valea, I. Mondragon, A. Arbelaiz, and B. Ferna, “Mechanical properties of flax fibre / polypropylene composites. Influence of fibre / matrix modification and glass fibre hybridization,” vol. 36, pp. 1637–1644, 2005.
 S. Mishra, A. K. Mohanty, L. T. Drzal, M. Misra, and S. Parija, “Studies on mechanical performance of biofibre / glass reinforced polyester hybrid composites,” vol. 63, pp. 1377–1385, 2003.
 T. P. Sathishkumar, J. Naveen, and S. Satheeshkumar, “Hybrid fiber reinforced polymer composites – a review,” Journal of Reinforced Plastics and Composites, vol. 33, no. 5, pp. 454–471, 2014.
 M. Rivai, a. Gupta, M. R. Islam, and M. D. H. Beg, “Characterization of oil palm empty fruit bunch and glass fibre reinforced recycled polypropylene hybrid composites,” Fibers Polym., vol. 15, no. 7, pp. 1523–1530, 2014.
 B. K. Deka and T. K. Maji, “Effect of Silica Nanopowder on the Properties of Wood Flour / Polymer Composite,” Polymer Engineering and Science, vol. 52, no. 7, pp. 1516–1523, 2012.
 R. Burgueno, M. J. Quagliata, A. K. Mohanty, G. Mehta, L. T. Drzal, and M. Misra, “Hybrid biofiber-based composites for structural cellular plates,” Compos. Part A Appl. Sci. Manuf., vol. 36, pp. 581–593, 2005.
 S. Y. Fu and B. Lauke, “Characterization of tensile behaviour of hybrid short glass fibre calcite particle ABS composites,” Compos. Part A Appl. Sci. Manuf., vol. 29, no. 5–6, pp. 575–583, 1998.
 S. Y. Fu, G. Xu, and Y. Mai, “On the elastic modulus of hybrid particle/short fiber/polymer composites,” Composites Part B: Engineering, vol. 33, pp. 291–299, 2002.
 S. Y. Fu, B. Lauke, E. Mader, C. Y. Yue, and X. Hu, “Tensile properties of short-glass-fiber- and short-carbon-fiber-reinforced polypropylene composites,” Compos. Part A Appl. Sci. Manuf., vol. 31, no. 10, pp. 1117–1125, 2000.
 S. Y. Fu, B. Lauke, E. Mader, X. Hu, and C. Y. Yue, “Fracture resistance of short-glass-fiber-reinforced and short-carbon-fiber-reinforced polypropylene under Charpy impact load and its dependence on processing,” J. Mater. Process. Technol., vol. 89–90, pp. 501–507, 1999.
 K. K. H. Yeung and K. P. Rao, “Mechanical properties of Kevlar-49 fibre reinforced thermoplastic composites,” Polym. Polym. Compos., vol. 20, no. 5, pp. 411–424, 2012.
 A. Kumar, V. V Chavan, S. Ahmad, and R. Alagirusamy, “International Journal of Impact Engineering Ballistic impact response of Kevlar ® reinforced thermoplastic composite armors,” Int. J. Impact Eng., vol. 89, pp. 1–13, 2016.
 J. Li, “The Effect of Kevlar Pulp Content on Mechanical and Tribological Properties of Thermoplastic Polyimide Composites,” J. Reinf. Plast. Compos., vol. 29, no. 11, pp. 1601–1608, 2010.
 J. Li, “The Effect of Carbon Fiber Content on the Mechanical and Tribological Properties of Carbon Fiber-Reinforced PTFE Composites,” Polym. Plast. Technol. Eng., vol. 49, no. 4, pp. 332–336, 2010.
 M. F. Omar, H. M. Akil, and Z. A. Ahmad, “Effect of molecular structures on dynamic compression properties of polyethylene,” Mater. Sci. Eng. A, vol. 538, pp. 125–134, 2012.
 S. Graefe, D. Dufour, M. van Zonneveld, F. Rodriguez, and A. Gonzalez, “Peach palm (Bactris gasipaes) in tropical Latin America: Implications for biodiversity conservation, natural resource management and human nutrition,” Biodivers. Conserv., vol. 22, no. 2, pp. 269–300, 2013.
 W. L. E. Magalhães, S. A. Pianaro, C. J. F. Granado, and K. G. Satyanarayana, “Preparation and characterization of polypropylene/heart-of-peach palm sheath composite,” J. Appl. Polym. Sci., vol. 127, no. 2, pp. 1285–1294, 2013.
 M. S. Salit, "Tropical natural fibre composites: properties, manufacture and applications." Engineering Materials., Singapore: Springer, 2014.
 E. E. Haro, A. G. Odeshi, and J. A. Szpunar, “The Effects of Micro- and Nano-Fillers’ Additions on the Dynamic Impact Response of Hybrid Composite Armors Made of HDPE Reinforced with Kevlar Short Fibers,” Polym. Plast. Technol. Eng., vol. 0, no. 0, pp. 1–16, 2017.
 ASTM, “ASTM: D638, Standard test method for tensile properties of plastics,” ASTM Stand., pp. 1–16, 2013.
 D570, “Water Absorption of Plastics 1,” ASTM Stand., vol. 98, no. Reapproved 2010, pp. 25–28, 2014.
 C. Weinong and S. BO, "Split Hopkinson (Kolsky) Bar: Design, Testing and Applications”, Mechanical Engineering Series, Springer, vol. 1, 2013.
 M. F. Omar, H. Md Akil, Z. A. Ahmad, A. A. M. Mazuki, and T. Yokoyama, “Dynamic properties of pultruded natural fibre reinforced composites using Split Hopkinson Pressure Bar technique,” Mater. Des., vol. 31, no. 9, pp. 4209–4218, 2010.
 A. A. Tiamiyu, R. Basu, A. G. Odeshi, and J. A. Szpunar, “Plastic deformation in relation to microstructure and texture evolution in AA 2017-T451 and AA 2624-T351 aluminum alloys under dynamic impact loading,” Mater. Sci. Eng. A, vol. 636, pp. 379–388, 2015.
 James K. Stewart, “NIJ 0108.01 - Ballistic Resistant Protective Materials,” US: National Institute of Justice, Washington, 1985.
 Fire A, Publication A. "NATO/PFPUN classified NATO international staff - defence investment division allied NATO reaction-to-fire tests for materials policy for the pre-selection of materials for military applications," STANAG 4602 Allied Fire Assessment Publication (AFAP), vol. 1, edition 3, July, 2010.
 Arvidsson PG. NATO "Infantry Weapons Standardization". NATO Army Armaments Group; Brussels, Belgium, 2008.
 M. Safety and I. Analysis, “STANAG 4241: Review of the Bullet Impact Test Background,” US: Munitions Safety Information Analysis Center; San Diego, 2013.
 E. Haro Albuja, J. A. Szpunar, and A. G. Odeshi, “Ballistic impact response of laminated hybrid materials made of 5086-H32 aluminum alloy, epoxy and Kevlar® fabrics impregnated with shear thickening fluid,” Compos. Part A Appl. Sci. Manuf., vol. 87, pp. 54–65, 2016.
 E. E. Haro, A. G. Odeshi, and J. A. Szpunar, “The energy absorption behavior of hybrid composite laminates containing nano-fillers under ballistic impact.,” Int. J. Impact Eng., vol. 96, pp. 11–22, May 2016.
 S. Abrate, " Impact engineering of composite structures,” CISM Courses and Lectures, vol. 526, Springer Wien, New York, 2011.
 I. Mohagheghian, G. J. McShane, and W. J. Stronge, “Impact perforation of monolithic polyethylene plates: Projectile nose shape dependence,” Int. J. Impact Eng., vol. 80, pp. 162–176, 2015.
 A. Ramezani Kakroodi, Y. Kazemi, and D. Rodriguez, “Mechanical, rheological, morphological and water absorption properties of maleated polyethylene/hemp composites: Effect of ground tire rubber addition,” Compos. Part B Eng., vol. 51, pp. 337–344, 2013.
 N. A. Mohd Ayob, M. Ahmad, and N. N. Mohd Khairuddin, “Water Resistance and Tensile Strength of High Density Polyethylene (HDPE) Composites,” Adv. Mater. Res., vol. 1134, pp. 34–38, 2016.
 M. Jacob, S. Thomas, and K. T. Varughese, “Natural rubber composites reinforced with sisal/oil palm hybrid fibers: Tensile and cure characteristics,” J. Appl. Polym. Sci., vol. 93, no. 5, pp. 2305–2312, 2004.
 M. D. H. Beg, J. O. Akindoyo, S. Ghazali, and A. A. Mamun, “Impact Modified Oil Palm Empty Fruit Bunch Fiber / Poly ( Lactic ) Acid Composite,” vol. 9, no. 1, pp. 165–170, 2015.
 A. Boudenne, L. Ibos, Y. Candau, and S. Thomas, "Handbook of Multiphase Polymer Systems.", John Wiley and Sons Ltd., vol. 1., 2011.
 H. Abdulhamid, A. Kolopp, C. Bouvet, and S. Rivallant, “Experimental and numerical study of AA5086-H111 aluminum plates subjected to impact,” International Journal of Impact Engineering, vol. 51, pp. 1-12, 2013.