Papers by Keyword: Kenaf Fiber

Abstract: Kenaf fiber possesses the capability for application in bio-composite materials, owing to its appealing mechanical and physical properties. This research aimed to achieve the optimum flexural strength of kenaf fiber/epoxy bio-composites materials with variations in kenaf fiber content, curing time, and curing temperature using a casting process. This study found that kenaf fiber addition increased the flexural strength of kenaf fiber/epoxy bio-composite, by varying curing time (30, 45, and 60 minutes) and curing temperature (60, 90, and 150 °C). The results showed that the highest flexural strength was obtained at 90°C (72.5 MPa) at 20/80 kenaf fiber content, at various curing temperatures. Meanwhile, the same highest flexural strength value (72.5 MPa) was also obtained for 20/80 kenaf fiber content, 45 minutes at various curing times. SEM image shows that 20 Wt.% kenaf fiber content has a better dispersion compared with 10 Wt.% so that affects the flexural strength value.

Abstract: Fiber reinforced concrete is a commonly used material to cater for the shortcomings of concrete, such as low tensile strength, brittleness, and rapid crack propagation. This paper presents an experimental study on the mechanical properties of the hybrid (steel-kenaf) fiber added into concrete mixture. Two types of fibers, namely hooked-end steel fiber and kenaf fiber were considered. A control specimen without fibers was used to compare with fiber reinforced concrete mixture considering 1% and 2% volume fraction. Mechanical properties, i.e., workability, compressive strength and flexural strength, were investigated. In this study, the kenaf fibers were treated by 6% concentration of Sodium Hydroxide (NaOH) through immersion in the laboratory for 24 hours. The results showed that the addition of hybrid fiber improves the performance of compressive strength and flexural strength of the concrete. Specimens with 2% hybrid fibers show the best flexural performance. Moreover, an increase in volume fractions of steel fibers leads to an increase in the compressive and flexural strengths of concrete. In addition, specimens with steel-kenaf hybrid fibers exhibit a better failure behavior than specimens without fibers.

Abstract: Reinforcement of both fibrous and particulate materials can improve composite properties for various applications, such as biomedical applications. The alkali-treated kenaf fibers and (SiO2, bentonite, and CaCO3) microparticles 400 mesh in size reinforce the epoxy matrix for hybrid composites. The bending and impact properties of hybrid composites, as well as their water absorption, are compared. The hybrid composites were prepared in a compression mold using a hand lay-up technique at 100°C for 20 – 50 minutes consisting of 28 vol.% of short kenaf fibers ~5 mm in length, 2 vol.% of each type of microparticle, and 70 vol.% the epoxy resin. The flexural and impact properties of kenaf/silica/epoxy composite indicated the highest flexural strength (58.37±3.9 MPa), flexural modulus (4.68 ± 0.17 MPa), and impact strength (7.49 kJ/m²⁾. The addition of the microparticles reduced water absorption in the composites. The water absorption of kenaf/silica/epoxy composite appeared to be stable for immersion time near 216 hours. Other microparticle-filled composites did not show this pattern. The incorporation of silica microparticles to the kenaf/epoxy composite potentially enhanced the mechanical properties of the composite, with the expectation of using it to be developed for biomedical composite material.

Abstract: In the current project, Kenaf fiber (K) and carbon fiber (C) with epoxy resin were utilized to form carbon-kenaf hybrid composites using a vacuum infusion technique. The volume fraction of fiber and thickness of a hybrid composite was fixed at 40 vol.% and 3mm, respectively. Four different sequences were introduced in the current project including CCCCC, KKKKK, KCKCK, and CKCKC. Mechanical testing such as tensile and flexural tests were performed according to ASTM D3039 and ASTM D790, respectively. Scanning Electron Microscope (SEM) and Optical Microscope (OM) were used to identify modes of failures in both tensile and flexural tests of carbon/kenaf hybrid composites. The hybrid CKCKC sample displayed a higher value in tensile strength (264.23 MPa), tensile modulus (11.06 GPa), flexural strength (438.51 MPa) and flexural modulus (25.13 GPa) as compared than KCKCK hybrid sample.

Abstract: The project explained about what happened to fiber matrix interfacial shear strength, fiber tensile strength and fiber Young modulus when different alkali treatment settings were applied. Kenaf fiber were exposed to different alkali concentration, immersion duration and immersion temperature. To determine the interfacial shear strength (IFSS), unsaturated polyester matrix was utilised to expose the properties. The effects of alkali treatment on sample mechanical properties were successfully evaluated, whereby the treated sample's IFSS showed slightly higher value compared to untreated kenaf fiber at all settings. Meanwhile, the IFSS value was increased at low alkali concentration and decreased with the increment of alkali concentration percentage. On the other hand, untreated kenaf fiber tensile strength and Young modulus average value was 632MPa and 40.65GPa respectively. It was also established that the sample's tensile strength was keep reducing after treatment at all settings. At 30 minutes constant immersion duration, the percentage of kenaf fiber tensile strength decrement was 42.57% when other treatment settings increased. Furthermore, a decline pattern was obtained in term of sample tensile strength and Young modulus when the alkali treatment increased at all settings.

Abstract: The study of vibration-damping factor on unsaturated polyester resin reinforced glass and kenaf fiber has been performed. Two variations of glass and kenaf fibers were made based on fiber volume fraction (V_f) and ratio of glass to kenaf fiber at V_f of 25 %. The measurement of the samples was to obtain the value of the vibration-damping factor and the elastic modulus. The result shows that the vibration-damping factor decreases proportionally to the addition of fiber. Increased stiffness is evidenced by an increase in elastic modulus along with an increase in fiber content. According ratio of glass to kenaf fiber, the vibration-damping factor decreases proportionally with the increasing of glass fiber content. Increased kenaf fiber content causes an increase in vibration-damping factor, a decrease in elastic modulus, and lead to decreased in stiffness of the hybrid composite.

Abstract: Nowadays natural fiber and polymer matrix are being extensively used as alternatives in producing furniture like ceiling, floor and etc. to fulfill society demand instead of environmental friendly and saving cost. The objective of this study is to investigate the effects of maleic anhydride grafted polypropylene (MAPP) as a coupling agent for reinforcement between kenaf fiber (KF) and polypropylene (PP). The ratio of MAPP between 3% and 5% was observed to determine which composition ratio is better. The tensile strength for both 30% KF and 40% KF was treated through the alkali treatment process with 5% sodium hydroxide (NaOH). Kenaf fiber reinforced polypropylene (PP/KF) composites were melt blended and then used hydraulic molding test press machine for characterization to observe their tensile strengths by measuring their threshold. Tensile test was carried out to determine the tensile stresses of the composite at the best composition ratio of kenaf fiber that are 30% KF and 40% KF instead of MAPP ratio. The result shows 40% KF (5% MAPP) lead to better tensile performance compared to 40% KF (3% MAPP), 30% KF (5% MAPP) and 30% KF (3% MAPP). Meanwhile, Scanning electron microscopy (SEM) is used to observe the morphological comparison between untreated KF and treated KF as well as PP/KF. The good interfacial bonding between KF and PP was 5% MAPP rather than 3% MAPP due to the optimum strength received. Overall 5% MAPP with 40% PP/KF had shown the best result compared to others with the estimated tensile strength value of 21.38 MPa.

Abstract: Natural fibers are potentially used as composite reinforcement in polymeric materials, but lacking of research exploration such as kenaf fibers has limited implementation in Malaysia. The advantages of natural fibers are renewable, less hazardous during fabrication and handling process and relatively cheaper as compared to synthetic fibers. The objectives of current project are to determine the fracture energy of woven fabric kenaf composite (KFRP) plates with various fiber orientations. The experiment framework includes a variation of fiber orientations as designated in testing series by using single-edge notch (SEN) testing technique. The experimental results demonstrated that testing coupons with woven fabric with 90^o fiber orientation has largest fracture toughness G_c value compared to other fiber orientations understudied. Good correlations and findings were found in other parametric studied.

Abstract: Kenaf bast fibers were prepared into two types as untreated and maleic anhydride (MA) treated. Unsaturated polyester (UPE) resin was used as matrix and applied onto the kenaf bast fibers using hand lay-up method. Transverse and longitudinal flexural properties of unidirectional long kenaf bast fiber reinforced unsaturated polyester composites were performed and the effect of fiber modification and loading were studied. It is found that the transverse flexural strength of both types of composites decreases with the increasing of kenaf loading. Contrary, longitudinal flexural strength of both composites increases with the increasing of kenaf loading. Improved transverse and longitudinal flexural properties are shown by MA treatment of kenaf bast fiber. The interactions between fiber and matrix of fractured flexural surface were also observed by scanning electron microscope (SEM).

Abstract: Kenaf fibers were immersed in 6% solution of sodium hydroxide (NaOH) for 1, 2, 3, 4 and 5 hours. The treated fibers were characterized with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The XPS results showed that the alkali treatment increased the proportion of oxygen atoms on the fiber surface as indicated by the increase in oxygen-carbon ratio. An increase in C2 peak (C-OH bonds) was also observed suggesting the present of cellulose on the fiber surface. The decrease in C1 peak (C-C bonds) suggested that lignin was removed from the fiber surface following the alkali treatment. Scale-like structures were observed from the AFM topographic images to indicate the presence of cellulose microfibrils in the primary cell wall of the treated fiber. Alkali treated fiber surface showed lower mean surface roughness than the untreated fiber indicating smoother fiber surface. The fiber surface became relatively smooth after the alkali treatment due to the removal of non-cellulosic layer.