Tensile and Flexural Properties of HDPE/PET/Kenaf Hybrid Composites

Natural fiber reinforced plastics (NFRP) is one of the advanced technologies
developed in the engineering material industry. The examples of NFRP are kenaf
fiber reinforced polypropylene (PP) composites; pineapple leaf fiber reinforced highdensity
polyethylene (HDPE), and others. The advantages of NFRP are
biodegradable, lightweight, low production cost and it does not release carbon
dioxide when burnt. NFRP has been extensively used in manufacturing the interior
parts of car and bumpers. Hybrid composite is defined as a matrix that bonds with
two or more reinforcements. Theoretically, hybrid composites offer better
mechanical properties than non-hybrid composites. This work aimed to the study of
tensile and flexural properties of HDPE/ Polyethylene terephthalate (PET)
fiber/kenaf hybrid composites with and without compatibilizer. Two equal weight
proportions of fibers were fabricated using compression molding technique at
processing temperature of 200oC. A compatibilizer was added to further enhance the
interfacial bonding between fibers and matrix. The samples obtained were undergone
tensile and flexural tests according to ASTM D638 and ASTM D790 respectively.
The overall result showed that the hybrid composites had higher tensile and flexural
properties with highest improvement recorded was 32% and 51% respectively
compared to neat HDPE. It was also found that the optimal fibers content for
achieving highest tensile properties was 20 wt%. For flexural strength, the optimal
fibers content was 30%. FESEM images were used to characterize the microstructure
of the hybrid composites.