Synthesis and characterisation of maleated polypropylene/ lalang fiber/ polypropeleyne composites: Optimisation preparation conditions and their properties

Polypropylene (PP) blend with natural lalang fiber (LF) were investigated in this study. LF was chosen in preparation of polymer composites because it is low cost, eco-friendly, abundance, renewable, biodegradable and shows excellent mechanical properties. Hence, LF has highly potential as a natural fiber filler in polymer composites. LF was prepared by drying the lalang leaves under the sun light and were crushed using hammer mill before they were soaked in 5 % sodium hydroxide (NaOH) solution. The fiber was then washed with distilled water until neutral. LF was dried in an oven then grinded and sieved into specific sizes. LF/ PP and maleated polypropylene/ LF/ PP (MAPP/ LF/ PP) composites were prepared by extrusion method using a twin-screw extruder between LF, PP and MAPP at different compositions. The LF/ PP and MAPP/ LF/ PP composites were shaped into 3 mm sheet samples using an electric hydraulic hot press at the temperature of 180 degree Celsius. Several studies were carried out to investigate the optimum preparation conditions including the effect of size and percentage of LF, as well as the percentage of MAPP on their mechanical properties using tensile tester and izod impact tester. Meanwhile, the thermal properties of PP, 15 % M size LF/ PP and 1 % MAPP/ 15 % M size LF/ PP composites were analyzed using thermo gravimetry analysis (TGA) and the characteristic of LF on the cross section of 15 % M size LF/ PP and 1 % MAPP/ 15 % M size LF/ PP composites were investigated using a digital microscope. (author)