Palm fiber (PF) reinforced acrylonitrile butadiene styrene (ABS) composite matrix was prepared by employing Injection Moulding Machine (IMM). Palm fiber was collected from ten different trees of different age group from Comilla region in Bangladesh. Three sets of samples were prepared for three different wt% (5%, 10% and 20%) of fiber contents. The mechanical (tensile strength, flexural stress, micro hardness, Leeb’s rebound hardness) and physical (bulk density and water absorption) properties were measured. The observed result reveals that the tensile strength (TS) and flexural stress (FS) were decreased with increasing fiber contents in the PF-ABS composites except 10% fiber content.
Although composite materials had been known in various forms throughout the history of mankind, the history of modern composites probably began in 1937 when salesmen from the Owens Corning Fiberglass Company began to sell fiberglass to interested parties around the United States [
Composite is defined as solid materials, which consists of a combination of two or more materials in which the individual component retains their separate identity [
One of the major environmental problems we are facing today is the plastic waste problem. The tremendous production and use of plastics in every segment of our life have increased the plastic waste in huge scale. The waste disposal problems have directed great part of the scientific research to eco-composite materials that can be easily degradable and bio assimilated [5,6]. The use of natural fiber as reinforcement for composites has received increasing attention and polymer based composites having natural fiber as reinforcement have the potential to be attractive alternative to synthetic fiber composites.
Natural fiber reinforcement increases biodegradability, reduces cost and decreases environmental pollution and hazards. Recently many types of natural fibers have been investigated for use in plastics including palm, flax, hemp, jute, straw, wood, rice husk, wheat, barley, oats, rye, bamboo, sugarcane, grass reeds, kenaf, ramie, sisal, coir, banana fiber etc. [
Acrylonitrile butadiene styrene (ABS) is a common thermoplastic terpolymer made by polymerizing styrene and acrylonitrile in the presence of poly butadiene. The proportions of contents in ABS can vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene. The nitrile groups from neighboring chains, being polar, attract each other and bind the chains together, making ABS stronger than pure polystyrene. The styrene gives the plastic a shiny, impervious surface. The butadiene, a rubbery substance, provides resilience even at low temperatures. For the majority of applications, ABS can be used between −20 and 80˚C as its mechanical properties vary with temperature [
A large number of experiments have performed with natural fiber reinforced polymeric composites all over the world. Mohammad, N. N. B. et al. [
Palm fiber would be a good reinforcing agent in ABS and will be a good area of research. With the addition of palm fiber in ABS, polymeric matrix could change the mechanical and physical properties of the composites. Therefore, the mechanical (tensile strength, flexural stress, micro hardness, Leeb’s rebound hardness) and physical (bulk density & water absorption) properties were measured in the palm fiber reinforced ABS composites in this study.
Palm leaves of ten different aged trees (five of them are above 10 years and another five of them are below 10 years) were collected from Burura region of Comilla district. Dividing ends of the middle hard part of the leaves were hammered. Hard part of the leaves was immersed in water for 20 days to rotten. Rotten materials were cleaned and fiber were then separated and dried under sun light. After that fiber was kept at 100˚C for 24 hours for partial removal of moisture. Acrylonitrile butadiene styrene (ABS) was collected from local market of old Dhaka of Bangladesh. After measuring some properties (Physical: Water absorption, Mechanical: Tensile strength and Thermal: TG/DTG) of palm fiber and ABS polymer, Palm fiber was cut to 1 - 2 mm in sized. ABS and small palm fiber were dried in dryer at 50˚C for 24 hours. Fined palm fiber and ABS polymer put into the injection moulding machine. This mixture was heated at 150˚C inside the injection moulding machine and molten mixture become composite and come out of the IMM. This composite was poured into different shape of die for different test. Three sets of composites samples (with 5%, 10% and 20% fiber content) were prepare to carry out this research.
1) Tensile and Flexural Property of Composite Mechanical property such as TS and percentage of elongation-at break [EB(%)] of the samples were measured by a universal testing machine (Hounsfield UTM 10 KN; ASTM D 3039/D 3039 M-00) [
2) Hardness of Composite A software controlled Vicker’s square based diamond indenter (Shimadzu, Japan) was employed to measure the micro hardness (H) from the residual impression on the sample surface after an indentation time of 6 seconds. Loads of 245.2 mN, 490.3 mN and 980.7 mN were used to derive a load indentation value of H in MPa by the following relation [
where d(m) is the length of indentation diagonal, P(N) is the applied load and K is a geometrical factor equal to 1.891. Sample with flat and smooth surface immediately after their preparation were used for this measurement. At least five imprints were taken on the sample surface for each load, and the H was calculated from the average value of all impressions.
Leeb’s rebound hardness test is one of the most used methods for testing hardness. The portability of Leeb’s tester can sometimes help to achieve higher testing rates without destruction of samples, which in most of the cases thus simplifies process and saves costs [
1) Bulk Density of Composites The bulk density of the composite materials was determined by measuring the weight and dimensions of the composite samples by using the following relation.
where Wt, L, W and H are the weight, length, width and height of the composites respectively. The samples were dried into dryer at 50˚C for 24 hours before measuring the density. Average densities were obtained using result from ten samples of each group.
2) Water Absorption Property of Composite The water absorption ability of the palm fiber reinforced ABS composites was carried out according to ASTM D 570-98 [
Where and are the weight of the sample after and before soaking in water.
The result of the mechanical tests in terms of tensile strength, flexural strength is presented in Figures 1-6.
Seung-Hwan et al. [
The effect of palm fiber loading on elongation at break of PF-ABS composites is shown in
cally with 5% fiber content. Then it increased for 10% fiber and again decreased for 20% fiber reinforced composites. For virgin ABS sample the flexural strength is 65.5 MPa, for 5%, 10% and 20% fiber content in composites is 62.5 MPa, 64.2 MPa and 61.57 MPa respectively and indicates that the filler-matrix interaction is in poor performance.
Figures 4-6 show the tensile stress-strain curve of the randomly selected composites with 5%, 10% & 20% fiber. The tensile stress for composites with 5%, 10% and 20% fiber contents are 37.32 MPa (C1S1), 39.3 MPa (C2S2) and 38.32 MPa (C3S7) respectively. By comparing three figures it is seen that tensile stress is slightly higher for 10% fiber contents in the composites.
Natural fiber and their composites are environmental friendly and renewable, however they have several bottlenecks. They have poor wet ability, incompatibility with some polymeric matrices and high moisture absorption. Due to high moisture absorption properties, there are formations of void in the composites which can reduce the mechanical properties of composite such as flexural strength [8,17].
content composites. Leeb’s rebound hardness increased with increase of fiber content in composites. Since the micro hardness decreased, which will create more rebound velocity, and then finally Leeb’s hardness increased.
The effect of the addition of fiber content on the water absorption behavior of the composites is shown in
Generally polymer likes ABS and polylactic acid can
absorb small amount of water while the PF-ABS composites absorbs more water due to the hydrophilic nature of the palm fiber (due to presence of polar group).Water may penetrate into the composite through the cutting/ interfacial side of the sample [
The mechanical and physical behavior of palm fiber reinforced ABS composites was studied. The mechanical properties did not change in the same ratio. The mechanical properties like tensile and flexural properties are the highest at 10% palm fiber content in the PF-ABS composites. This was attributed to the fact that the random fiber orientation resulted in lower properties. Treatment of palm fiber in ABS matrix does not bring regular and considerable change in the mechanical properties of the composites. Physical properties as water absorption property showed that with the increase of fiber content in the composites, water absorption increases.