Natural fibres potentially offer better reinforcement to improve the mechanical and physical properties of polymer composites. However, these natural materials at this stage are not fully explored yet due to the fibres themselves have limited heat resistance and are quite sensitive to moisture. This limitation will weaken the adhesion when interacting with thermoplastic matrices during the processing of composites. Therefore, the main purpose of this study is to investigate inherent strength characteristics among kenaf (core and bast) fillers as a reinforcement in polypropylene composites at various geometries and loadings via the injection moulding process. The composite materials consisted of kenaf with the geometric core filler of the 20 mesh (992 µm), 40 mesh (460 µm) and bast filler (166.9 µm) were mixed with polypropylene based on the filler loadings of 10 up to 40 wt. %. The results showed that bast filled composites had the highest tensile strength of 19.52 MPa at 30 wt. %, compared to core filled composites. Instead, 20 mesh core filled composites were obtained had the highest flexural strength which values were 25 MPa and 29 MPa at 20 wt. % and 30 wt. %, respectively. While 40 mesh core filled composites had the highest values of 25.35 MPa at 40 wt. % of filler loading compared to bast filled composites. SEM micrograph images showed the good interfacial bonding of core filler which surrounded by PP leading to diffusion and permeation of bonding. In conclusion, the use of kenaf (core and bast) fillers as a reinforcement in composite materials is reasonable to maximise the use of fibre from natural sources.
Composite materials have increasingly become crucial in manufacturing engineering products and producing commodity
materials in the major industries including; automotive, aerospace, marine, construction, agriculture and health science.
However, several improvements regarding the strength, dimensional stability and the cost of production are required.
In this study, composite of Kenaf, multi-wall carbon nanotube (MWCNT) and polypropylene (PP) with maleic anhydridegrafted
polypropylene (MAPP) are examined. The results highlight that increasing MAPP loading, in turn, increases the
value of the mechanical properties. The composites are produced by blending kenaf/MWCNT/PP using a Sigma blade
mixer and injection moulding. Injection moulding is a significant operation used to produce plastic products. In the
study, Kenaf core fibre was mixed with MWCNT and polypropylene, in addition to MAPP. The MAPP is added by applying
different percentage (1, 2, 3 and 4 wt. %) during the blending process. The main objective of the study was to analyse the
effects of MAPP concentrations on the mechanical properties of the Kenaf/MWCNT/PP composite. The results of the study
established that MAPP 3 wt. % concentration with MWCNT 3 wt. % loading and Kenaf 30 wt. % filler provide optimum
results for the composites. There was approximately, a 21% enhance in tensile strength of Kenaf 30 wt. %/MWCNT, 3 wt.
%/MAPP, 3 wt. %/PP observed compared to the (without) MAPP composite. The composites with coupling agent stimulate
better filler dispersion between Kenaf, MWCNT and PP observed using a scanning electron microscope (SEM) and fieldemission
scanning electron microscope (FESEM).