Starch-grafted-polypropylene/kenaf fibres composites. Part 1: Mechanical performances and viscoelastic behaviour

2009

In a view to reduce the cost of production and the harmful destruction of our environment, so many research work has been conducted and still ongoing as to the possibility of using natural fibres that are wholly degradable in combination with biodegradable thermoplastic materials. This has shown significant result so far and this effort needs to be further consolidated so that our environment can be safe and saved from destruction. It is for this reason that this paper is geared through reviewing studied and published results and brings out converging problems associated with biodegradable composite and partially degradable ones so that these associated problems can be tackled in further research. This review however will focus on Kenaf; a very important natural fibre with robust mechanical properties. Good number of journal papers have been reviewed here that touch on cultivation of kenaf and its consequent effect, chemical treatment of natural fibres, matrix combinations, processing techniques, environmental effects on composite, critical fibre length, some works done on Malaysian cultivated kenaf and use of coupling agents to improve linkages between fibre and polymeric matrixes. Most of the studies so far discussed tend to arrive at the problem of wettability of the composites which inhibits further increase in fibre loading and consequent fibre pull-out. Various areas of further study have been highlighted to tackle the aforementioned problems in composite production.

IOP Conference Series: Materials Science and Engineering, 2018

The effect polypropylene maleic anhydride (PPMAH) as a compatibilizer in mixing of polypropylene (PP) with kenaf fiber (KP) has been studied. Seven (7) different PP/KF composites ratio (100/0, 95/5, 90/10, 85/15, 80/20, 75/25 and 70/30) where compatibilizer use for PP/KF composite with fixed 3 wt% of maleic anhydride grafted polypropylene were carried out. In this project, all compound preparation was done by using a heated two-roll mill at a temperature of 180 °C for 7 minutes total of the mixing process. Then, the mixture was moulded by using a hot press machine at a temperature of 180 °C for a total 12 minutes to form 1 mm sheet and then cut into dumbbell shape. This sample was tested for mechanical properties include tensile strength, young modulus and elongation at break and morphology of the fracture surface of PP/KF composites. The result show PP/KF composite with compatibilizer has a higher tensile strength and young modulus compare to uncompatibilizer PP/KF composite. The adhesion between fiber and matrix has improved with addition of PPMAH compatibilizer. It make the PP/KF composite increase the stiffness and tensile strength. The scanning electron microscopy (SEM) study of tensile fracture surfaces of the PP/KF composites also indicates improved adhesion of kenaf fiber with polypropylene matrix with the presence of PPMAH compatibilizer.

IOP Conference Series: Materials Science and Engineering, 2019

Kenaf is a non-woody plant, which has high potential fiber to be used as polymer matrix reinforcement. Different compositions of kenaf fiber as bio reinforcing material at different fabrication process parameters will produce different biocomposite properties. This study uses kenaf fibers in the composition of 10, 20, and 30 wt.% as reinforcing material. Kenaf fiber and epoxy resin were mixed based on predetermined compositions, stirred using a mechanical stirrer at 200 rpm for 10 minutes. Then the mixture is poured into a mold and placed on a hot press machine. Pressure of 50 kg/mm 2 for 30 minutes at 150 0 C is used to produce kenaf fiber/epoxy biocomposite. The result showed that the increasing of kenaf fiber content in the matrix is succeeded to increase the flexural and impact strength of the biocomposite kenaf fiber/epoxy produced. The highest flexural strength (136 MPa) and highest impact strength (180 KJ /m 2) were obtained at a composition of 30 wt.% Kenaf fiber.

Universiti Malaysia Terengganu Journal of Undergraduate Research

Renewable materials have some bearing on the environment and have since increased research works related to polymer composites. This work was conducted to investigate the effects of interwoven kenaf fibers and the use of kenaf fibers in composites. In this research, interwoven between kenaf and polyethylene terephthalate (PET) was prepared and epoxy was used as the polymer matrix to form composites. The kenaf fiber composites with various kenaf fiber contents (2, 5, 8, and 10 wt %) interwoven with (PET) fibers were prepared by using open mould method. The properties of kenaf/PET/epoxy composites (KPTE) were studied. The kenaf fiber composites characterization was determined based on their mechanical properties, water absorption, morphology and thermal properties. The tensile strength test was performed using Testometric machine. The finding shows that the strength increases as the amount of kenaf fibers in the composites increases. The composites with 10% kenaf fibers interwoven PET...

Key Engineering Materials, 2011

In evaluating thermoplastics for their effective performance during processing, rheology properties are very useful. Similarly, in designing processing apparatus, knowledge of rheological behavior of composite melt is critical. In this study, melt flow and viscosity behavior of polypropylene/kenaf fibre composite was investigated using a single-screw extruder. Subsequently, flow behavior of the compounded formulation were evaluated by comparing the melt flow index, flow curve and viscosity curve of the PP and that of the composites at 190 o C processing temperature and varying the fibre size. There appears to be a positive linear increase of the apparent shear stress with increase in the apparent shear rate and, as expected, viscosity values for the composite samples are much higher than the PP especially at larger fibre size. The additional of kenaf fibre in composite reduces the MFI value basically because of the hindrances in the plastic flow of the polymer. In addition the increase in viscosity with increase in fibre loading might contributed to the high specific area of the fibre in the matrix thereby increasing the shear stress in the composite. Moreover loading of polymer system with fibre tends to disturb or disorganize the normal free movement of the polymer and certainly hindered the mobility chain segments in flow.

Journal of Polymers and the Environment, 2013

Non-woven composites were produced using kenaf (bast) fiber and polypropylene (PP) fiber. The effects of needle punching process, number of needle and kenaf fiber loadings on the properties of non-woven composite were studied. The aspect ratio of kenaf fiber was also measured in this study. The aspect ratio of most of kenaf fiber used was in the range of 200-400. The results indicated that the mechanical strength of the non-woven composite was significantly influenced by the percentage of kenaf fiber. This may due to the evenly mixed kenaf and PP fibers during carding process prior to the mechanical interlocking by needle punching process. The tensile strength, modulus and toughness were enhanced with the incorporation of carded and needle punched fibers. The number of needle used in needle punching process had a significant effect on the strength of the composite. This was evident in SEM micrograph where composite prepared from carded to needle punched non-woven web showed better wettability as compared to composite prepared from carded non-woven web only. However, no significant difference was observed in water absorption and thickness swelling tests for composites prepared with different number of needles.

Industrial & …, 1995

Kenaf (Hibiscus cannabinus) is a fast growing annual growth plant that is harvested for its bast fibers. These fibers have excellent specific properties and have potential to be outstanding reinforcing fillers in plastics. In our experiments, the fibers and polypropylene (PP) were blended in a thermokinetic mixer and then injection molded, with the fiber weight fractions varying to 60%. A maleated polypropylene was used to improve the interaction and adhesion between the nonpolar matrix and the polar lignocellulosic fibers. The specific tensile and flexural moduli of a 50% by weight (39% by volume) of kenaf-PP composite compare favorably with a 40% by weight of glass fiber-PP injection-molded composite. These results suggest that kenaf fibers are a viable alternative to inorganic/mineral-based reinforcing fibers as long as the right processing conditions are used and they are used in applications where the higher water absorption is not critical.

Jurnal Teknologi, 2014

Natural fiber is usually used as reinforcement in polymeric materials, and short fibers are commonly used for non-structural applications. However, the lack of studies on long fiber reinforced polymeric materials, especially kenaf fiber, has limited its usage in Malaysia. This paper presents the experimental results of a series of tensile tests conducted on continuous kenaf fibers produced with different types of thermoset resin (epoxy, polyester, and vinyl ester) arranged longitudinally. A total of 75 kenaf fiber reinforced polymer composites containing up to 50% fiber volume fraction including 15 neat samples as control samples were produced. Then, the samples were tested using Universal Testing Machine to obtain their tensile behaviour. Results indicated that the composites' performance increased gradually with every increment of fiber volume fraction. Factors affecting the tensile behaviour of kenaf fiber reinforced polymers are also explained and discussed. In conclusion, kenaf fiber can be used as reinforcing materials in polymeric materials.

Applied Mechanics and Materials, 2014

The effect of maleated polypropylene (MAPP) as binder on the mechanical properties of kenaf fibre/polypropylene (KF/PP) composites is studied. Ratios between kenaf fibre and PP having 10:90, 30:70 and 50:50 in weight ratio were selected. Further, MAPP having 1, 3 and 5 percent in percentage of weight ratio was mixed in KF/PP composites. Hot press machine was used to produce tensile test samples of KF/PP composites. The mechanical properties that are tensile strength, tensile modulus and elongation at break of KF-PP composites were obtained from tensile test result. It is found that the tensile strength and tensile modulus increase with increasing the kenaf fibre loading and higher percentage of MAPP. Further, the elongation at break for KF/PP composites shows lower result when increasing of kenaf fibre loading. However, when percentage of MAPP added in KF/PP composites increases, the elongation at break increased slightly. Thus, result shows that kenaf fibre/PP composites with binde...

Journal of Scientific and Engineering Research, 2017

In this research, natural fibre such as kenaf core fibre (KCF) was used as filler for preparation of the biocomposites. Low-density polyethylene (LDPE) has been selected as a polymer matrix for preparation of the biocomposites due to its low production cost. Besides that, chitosan was used as secondary filler to investigate its effect on mechanical properties of the prepared biocomposites. Brabender internal mixer was used to composite the materials at temperature of 150°C. The process was taken about 15 minutes to complete the compositing. After that, the biocomposites were moulded into sheet with 1 mm thickness by using compression moulding machine at 150 °C for 2 minutes. Then, the samples were cut into dumbbell and rectangular shapes to perform tensile and impact tests, respectively. For tensile test, the machine used was Instron universal testing machine which done according to the ASTM D638-10, while for impact test, the machine utilised was Instron impact testing machine which conducted in accordance with the ASTM D256-10. The results of tensile stress,tensile modulus, tensile strain and impact strength were recorded and analysed at the end of the tests.