International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 02 | May-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET.NET- All Rights Reserved Page 546 Effect of Short Polyamide Fiber on Impact Property of Polypropylene Composite Abduel Majid K. Najjar 1 , Adnan Agieli A. Aboulgasemb 2 1 Department of Chemical Engineering, Faculty of Engineering Al-Garabolli, Al-Mergeb University, Al-Mergeb- Libya 2 Department of Chemical Engineering, School of Engineering, Academy of Higher Studies, Zanzaour-Libya ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract -This work aimed at the investigation of the effects of the addition of a short polyamide fiber and carbon black powder on the impact strength and the surface hardness of polypropylene composite. The composite sheets were produced by using compression mould technique at different processing temperatures and times. The weight percentage of both polyamide fiber and carbon black in the composite were varied. The obtained results illustrated that processing temperature and time had insignificant effects on the surface hardness. The optimum fiber and carbon black contents under the experimental conditions were 9.22% and 0.245%, respectively. Processing temperature, fiber content and carbon black content had a reverse effect on the impact strength of the composite while the maximum value of the impact strength of 23.63 Kj.m -2 was recorded when the composite heated up to 7 min. . Key Words: Polypropylene composite, Polyamide fiber, Melt flow index, Impact strength, Hardness. 1. INTRODUCTION There is extremely need to carry out more studies on the modification of polymer properties in order to extend their applications. Polypropylene is among thermoplastic polymers and has broad applications. Preference is given to propylene for its bulk, inert nature and low density. It has been used as a main matrix for fiber-reinforced polypropylene composites. Synthetic fiber-reinforced polypropylene composites have raised tremendous interest among materials scientists and engineers in last decades due to their desirable physical and mechanical properties. Lately, we can observe their applications in almost every industrial application; including constructions, aerospace, automotives, marine, furniture, carpet and blankets. Generally, synthetic fiber is known to exhibit good mechanical properties and blending the fiber with polymer matrix could lead to potential improvement of some composite mechanical properties. Quazi and his colleagues have reviewed the mechanical properties of polypropylene composites containing synthetic or natural fibers [1]. They have concluded that the mechanical properties of polypropylene composite vary according to fiber nature and content. In addition, synthetic polypropylene fiber composites have greater mechanical properties than that of natural polypropylene fibers composites. Impact strength and hardness are some of the mechanical properties that are considered significant for fiber reinforced polymer composites. Previous studies have revealed how nature and type of fiber such as wood fiber [2] plant and animal based natural fibers [3], natural lingo- cellulose [4], jute fiber [5], flax fiber [6] affect the impact property of polypropylene composite. These properties also varied with processing temperature, processing time and chemical composition [5]. Introduction of fiber plays an important role in the impact resistance of the composite as it interacts with the crack formation and act as stress transferring medium [7]. Due to the fact that synthetic fibers have the ability to absorb high energy during impact than the natural fibers, Ruhul and his co- workers have revealed poor fiber matrix adhesion for jute- based composites when compared to that of the E-glass fiber composites [8] . Disadvantages of reinforcement of the polymers by natural fibers resulted from biodegradation and UV- degradation of natural fibers in long-term composite applications, decomposition of natural fiber at relative high processing temperatures and duration of thermal exposure, in addition to high moisture absorption [5]. Biodegradability and moisture absorption characteristics of the natural fibers could eliminate their application in the polymer composites particularly in products intended for long term use. Strong fiber with high failure strain imparts high work of fracture on the composite. The major drawback associated with the use of fibers as reinforcement in polypropylene matrix is mainly dependent on interfacial bonding between the fiber and the polymer. Previously published work showed that the addition of polyamide finer and carbon black to polypropylene matrix has affected the