Processing and properties of pineapple leaf fibers‐polypropylene composites prepared by twin‐screw extrusion

Pineapple leaf fiber (PALF) is an agricultural waste, very abundant in some countries of East Asia (India, Thailand, and Philippines). Owing to its intrinsic mechanical properties, it could be used as a reinforcing fiber for thermoplastic polymers. In this article, PALF was used to prepare polypropylene-based composites by twin-screw extrusion. The variation of the fiber dimensions (length, diameter, and aspect ratio) induced by the compounding process was analyzed. PALF suffer from a significant reduction in length, but the bundles are very difficult to separate and their diameter remains almost constant. The change in fiber length and aspect ratio along the screw profile showed an exponential decrease, as already observed for other lignocellulosic fibers. The mechanical properties of composites prepared with 20 wt% PALF fibers show an increase in Young's modulus (+46%) and stress at break (+12%), but a strong decrease in elongation at break (−98%). These results confirm the potential value of this agricultural waste as effective reinforcing fiber for polymer composites. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers