153 research outputs found
Effects of Banana Pseudostem Filler and Acrylic Impact Modifier on Thermo-Mechanical Properties of Unplastisized Polyvinyl Chloride Composites
The main objective of this study is to investigate the effects of banana pseudo-stem
(BPS) filler and acrylic impact modifier on mechanical and thermal properties of
unplastisized poly (vinyl) chloride (UPVC) composites. BPS/UPVC composites
with up to 40% by weight filler content were produced using the compression
moulding. The use of BPS fibre as filler in the composites contributed to the
enhancement of stiffness, but decreased the ductility, tensile and flexural strength of
the UPVC composites. It was also revealed that composites with increased impact
modulus and hardness could be successfully developed using BPS filler. The
thermal stability of acrylic modified and unmodified BPS/UPVC composites has
been studied. The results showed that the BPS filler degraded before UPVC matrix
and the BPS/UPVC composites are more stable than both components. The thermal
stability of acrylic modified BPS/UPVC composites was found to be higher than
that of unmodified BPS/UPVC composites. The dynamic mechanical properties (storage modulus and tan δ) of neat UPVC and BPS filler–UPVC were studied at
temperatures ranging from 30 to 140 °C. The gradual addition of 10% filler to the
neat UPVC matrix increased the storage modulus of the composites. The highest
stiffness has been obtained for 40% BPS filler of BPS/UPVC composites. This
could be attributed to the highly restricted movement in the side chain or adjacent
atoms in the main chain. The damping properties with the addition of acrylic also
decreased with the gradual addition of 10% filler. The glass transition temperature is
clearly seen to increase as the filler content increases, which is consistent with the
theory that the incorporation of filler has a restricting effect on segmental mobility
of the molecular structure. Overall, it can be concluded that BPS, which is
agricultural by-product from banana trees, has the potential to be used as filler in
UPVC composites as it enhanced the stiffness and reduced the cost of the
composites
Properties of kenaf filled unplasticized polyvinyl chloride composites
Combination of lignocellulosic fiber with thermoplastic is leading to the new areas of research in plastic composite field. Due to the problem of petroleum shortages and encouragement for reducing the dependence on fossil fuel products, thus increased the people interest in maximizing the utilize of renewable materials like kenaf fiber. By adding optimum natural fiber to thermoplastics could provide some cost reduction to the world of plastic industry as well as to dominance the agro-based industry. With a view to identifying the effect of fiber content and effect of coupling agent in kenaf fiber reinforced unplasticized poly (vinyl chloride) (UPVC) composite on the mechanical properties, the fiber and matrix mixture were mixed with poly [methylene poly (phenyl isocyanate)] (PMPPIC) using thermal mixing process followed by compression molding technique for the composite preparation that required for tensile characteristic (ASTM D638). The fiber loading were 10%, 20%, 30%, and 40% in weight. Since the kenaf fiber and UPVC are chemically different, the compatibility and dispersability of kenaf fiber in UPVC can be improved by lowering the surface energy of the fiber to make it less polar, consequently more similar to the plastic matrix. Generally, PMPPIC act as a bonding agent that facilitates the optimum stress transfer at the interface between fiber and matrix which gives an optimal mechanical performance of kenaf fiber reinforced UPVC composites. Meanwhile, the addition of 30% fiber contents with PMPPIC was successful to enhance the tensile properties and the efficiency of PMPPIC was verified using Fourier Transform Infra-Red (FTIR) spectroscopy
Rheological behaviour of polypropylene/kenaf fibre composite: effect of fibre size
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 190oC 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
Sugar palm fibre and its composites: a review of recent developments
The use of natural fibres as reinforcement in composite materials has increased over the years due to the rapid demand for renewable, cost-effective, and eco-friendly materials in many applications. The most common and adopted natural fibres used as reinforcements are flax, kenaf, hemp, jute, coir, sisal, and abaca. However, sugar palm fibre (SPF) as one of the natural fibres is gaining acceptance as a reinforcement in composites, though it has been known for decades in the rural communities for its multipurpose traditional uses. Sugar palm fibre (SPF) is extracted from sugar palm tree typically from its four morphological parts, namely, trunk, bunch, frond, and the surface of the trunk, which is known as Ijuk. In this paper, sugar palm tree, its fibre and composites, and biopolymers derived from its starch are discussed. Major challenges and the way forward for the use of sugar palm fibre and its composites are highlighted. This review also opens areas for further research on sugar palm fibre and its composites for academia and industries
Selection of natural fibre for hybrid laminated composites vehicle spall liners using analytical hierarchy process (AHP)
Natural fibres with variable properties are found in many engineering applications because of its low cost and biodegradability .The selection of suitable fibres involves the evaluation of a number of alternatives based on certain criteria. The purpose of this study is to suggest the use of analytical hierarchy process (AHP) in the selection of natural fibres for hybrid laminated composites. It was found that the most suitable natural fibre to be used with Kevlar 29 in hybrid laminated composites is kenaf fibre. It is expected that this finding will significantly contribute to the development of hybrid laminated composites for vehicle ballistic protection
Effect of fibre size and fibre loading on tensile properties of hybridized kenaf/PALF reinforced HDPE composite
Hybridization, especially where only variant natural lignocelluloses are combined, is fast receiving encouraging attention because it offers range of properties that are quite difficult to obtain with a single kind of reinforcement. In this work, tensile strength and modulus of hybridized kenaf/PALF reinforced HDPE composite was examined. Pellets were produced form the mixture of the composite in an internal mixer at 190°C, 40rpm and 25minutes for processing temperature, speed and duration of mixing respectively. The composite sheets with thickness of 1mm produced from pellets were prepared using compression moulding. Then the tensile specimen were prepared and tested using an INSTRON bluehill universal testing machine according to ASTM D638 requirements. All samples were prepared at 1:1 kenaf:PALF ratio; ≤0.25mm and ≤0.5mm fibre length; fiber loading of 10 to 40% were utilized. Linear relationship of tensile modulus was observed with about 26% reduction in tensile strength at 10% fibre loading that subsequently reduced but with a reversal increase at 40% fibre loading. This was attributed to a better supportive load at that fibre content and a better interaction between fibre and matrix. Furthermore, the result also corroborates with the one obtained for the tensile modulus at same fibre loading. The best tensile strength and tensile modulus obtained was 32.43MPa;642.61MPa and 30.01MPa;636.73MPa for 0.25mm and 0.5mm fibre length respectively. Increase in fibre length did not show any significant improvement in tensile strength which may have been coursed by fibre attrition. It is possible to achieve improved mechanical properties if the fibres are given some kind of treatment
Mechanical properties of natural fibre reinforced PVC composites : a review
Poly (vinyl chloride), which is commonly abbreviated as PVC, is widely used due to it being inexpensive, durable, and flexible. As a hard thermoplastic, PVC is used in the applications such as in building materials pipe and plumbing. The factors that should be considered in using PVC is safety and environmental issues. Mixing PVC with natural fibres is an interesting alternative. The main challenge in the research on natural fibre/polymer composites is the poor compatibility between the fibres and the matrix because this will affect their bonding strength. During the mixing with PVC, some natural fibres may acts as reinforcing materials while other natural fibres only act as filler, which contribute less to mechanical strength improvement. However, generally natural fibres also give positive outcome to the stiffness of the composites while decreasing the density
Physico-chemical and thermal properties of starch derived from sugar palm tree (Arenga pinnata)
Petroleum based polymers are extremely stable and commonly used in various industries include food packaging, furniture and automotive. However, the waste that come from petroleum based polymer material has brought negative impact not only for human being, but also create the serious environmental problems. Hence, biopolymers that come from natural source such as starches are now being considered as an alternative to the existing petrochemical based polymers. This study was aimed to examine the potential of sugar palm starch extracted from sugar palm tree (Arenga pinnata) as a new biopolymer. The important properties of sugar palm starch studied were the chemical properties, thermal properties, particle size and morphological surface. The starches isolated from sugar palm tree contained comparable amounts of amylose (37.60 %) which were higher than tapioca, sago, potato, wheat and maize. The results showed significant differences in the chemical content as well as in the granule sizes of sugar palm starch. Thermal characteristic studies using thermogravimetry analysis and differential scanning calorimetry showed that sugar palm starch was thermally stable than other starches. Study on morphological surface indicated that sugar palm starch were rounded and oval-shaped
Optimizing processing parameters for hybridized kenaf/PALF reinforced HDPE composite
This work is aimed at achieving optimum processing parameters for Kenaf/PALF/HDPE. Processing parameters like temperature, speed of rotor and duration of composite mixing in an internal mixer were examined. Oven conditioned and unconditioned specimen were prepared and tested. The best tensile strength and tensile modulus were obtained at an optimum processing parameters of 190°C, 40rpm, and 15min for temperature of processing, speed of rotor and duration of mixing respectively, while 190°C, 40rpm and 20min gave the best flexural strength and 190°C, 40rpm and 25min for flexural modulus. Conditioning of composite tends to reduce its tensile modulus while increasing its strength and flexural modulus. All samples were produced at only 10w% (mass) of fibre in the composite at 1:1 and less than 0.3mm fibre ratio and length respectively. Utilization of these parameters according to end requirement can help in achieving optimum mechanical properties on hybridized composites
The effect of aging temperature on mechanical properties of banana pseudostem fiber reinforced polymer composite
Polymer composites using natural fibers as the reinforcing agents have found their use in many applications. The initial development of polymer composite based on high density polyethylene (HDPE) with banana pseudostem fiber was studied based on the effect of non-aging and aging treatments. Tensile, flexural and impact tests were performed to investigate the mechanical properties of banana pseudostem fiber reinforced composite. Flexural and impact test results show that the specimen strength improved after aging treatment was applied. However, the tensile test results gave a reverse effect on the strength of the composite after aging. The specimen became more brittle when the composite was exposed to the aging temperature
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