Abstract: PLA has limited applications due to its inherent brittleness, toughness and low elongation at break. One of the options for improvement is through blending with polyoxymethylene (POM). Melt blending of polylactic acid (PLA) and polyoxymethylene (POM) at 90/10 PLA/POM composition was carried out in a twin-screw extruder. The PLA/POM was loaded with 1 – 5 wt.% of nanoclay (Cloisite C20). The blends were then characterized for mechanical, morphological, chemical and thermal properties. It was found that tensile strength, Young's modulus, and elongation at break improved when the loadings of nanoclay were increased. Chemical analysis by FTIR revealed that PLA/POM blend is immiscible.
Abstract: In this report presented the investigation of axial progressive compression on sandwich composite cylinder made from basalt fibre reinforced composite tube as skins and polyurethane (EPU) foam as core of the structure. The effect of braid orientation angle of the sandwich skins and foam core thickness were evaluated on the parameter performance namely peak force, average force, total energy absorption, crush force efficiency, and specific energy absorption. The primary failure mode observed was progressive failure fibre cracking and tube’s wall folding and crumping. Experiment result showed that the effect of outer wall braid angle of sandwich tube structure was the dominant factor contributed to high energy absorption capacity. Furthermore, the foam thickness has no significant influences on the SEA value; however, the total diameter size of sandwich tube skins was.
Abstract: Current work reports on evaluation of bulk mechanical properties of High Density Polyethylene (HDPE) reinforced with functionalized 1D (Multi Walled Carbon Nanotubes- (MWCNTs) and 2D (hexagonal-Boron Nitride Nanoplatelets-(h-BNNPs) fillers. Mechanical mixing and injection moulding technique was used to prepare the composites. Evaluation of bulk mechanical properties like hardness, yield stress, fracture stress, impact toughness and Young`s modulus was carried out. The optimum properties were exhibited by HDPE/0.25 MWCNT/0.1 BNNP. Hardness, yield stress, fracture stress, impact toughness and Young`s modulus was observed to increase by 93.84, 80.83, 59.23, 115 and 42.05% on comparison with pure HDPE. TEM images confirm the tubular and hexagonal morphology of MWCNT and h-BNNP. It is concluded from test results that addition of MWCNT and h-BNNP into HDPE has improvised mechanical properties.
Abstract: In this study, acid-doped polyaniline-zinc oxide composites were prepared and used to investigate their effect on the removal of methyl orange dye under visible light exposure. The composites were prepared by mixing different volume fractions of polyaniline and ZnO powders. Their effect on the removal of methyl orange was determined through transmittance spectroscopy. Polyaniline-zinc oxide composites of 75% volume fractions showed the highest percent removal of methyl orange. This was attributed to the presence of p-n heterojunctions and adsorption capability of the polyaniline molecules.
Abstract: CuSO4-deposited and CuO-deposited polyurethane foam (PUF) were fabricated in this study. Image analysis showed color transformation of the PUF from yellow to blue-green, which is indicative of the deposited CuSO4 particles on the substrate. Further color transformation of the material from blue-green to greenish-brown after soaking in NaOH suggest that the CuSO4 oxidized to form CuO, which was confirmed by the presence of CuO peaks during XRD analysis. SEM images also reveal the presence of CuO rods embedded in the PUF. The antibacterial activities of the CuSO4- and CuO-deposited samples against the gram-negative Escherichia coli bacteria were conducted.
Abstract: Present work reports on Dynamic Mechanical Thermal Analysis (DMTA) of HDPE reinforced with surface modified 0D (Nanodiamonds-NDs), 1D (Multi Walled Carbon Nanotubes-MWCNTs) and 2D (Graphite nanoplatelets-GNPs) nanofillers. Composite samples were prepared using twin screw injection moulding machine. Dynamic properties like storage, loss modulus and tan delta were investigated as a function of temperature and at constant oscillation of 1 Hz. Optimum properties were exhibited by 0.1 CNT/HDPE during a temperature swept from 30 to 110 oC. The storage modulus and loss modulus of 0.1 CNT/HDPE increased by 57 and 28% on comparison with pure HDPE. 0.1 CNT/HDPE exhibited highest ascent during tan delta evaluation confirming good damping property. TEM analysis was carried out to investigate the morphology of ND, MWCNT and GNP.
Abstract: Sago (Metroxylon spp) is one of plant that contains high starch, so it has potential to be utilized as raw material for biopolymer production. This study aims to compare the properties and morphology of sago starch-based biopolymers reinforced by different filler types, including clay, cellulose, zinc oxide and chitosan. Biopolymer sample was prepared at 75 °C with ratio of water to the starch of 10 ml/gr, glycerol content of 0.1 ml/gr of the starch and filler content 6% w/w. The testing included tensile, water uptake and biodegradability properties according to ASTM D882, ASTM D570 and DIN EN ISO 846 standards, respectively. Other testing also conducted for morphology by using scanning electron microscope (SEM). The results showed that biopolymer with chitosan filler has better tensile, water uptake and biodegrability properties compared to other filler type, with tensile stregth of 11 MPa, elongation at break of 9%, water uptake of 10% and biodegrability of 40%. The SEM micrograph shows that the filler still has an agglomerated portion in the starch matrix. Increasing the biopolymer properties is still possible by improving the morphology.
Abstract: In this short review paper, the physical and mechanical properties of acacia wood, poly lactic acid (PLA) and polyhydroxyalkanoates (PHA) were analyzed. Existing factors that affect the mechanical properties of natural fiber composites were investigated and identified. By knowing these factors, a possibility and potentiality in implementing the natural acacia wood reinforced material with hybrid polymer were discussed. It was found that the acacia wood had the potential to re-condition soil and have the potential to become reinforced materials in hybrid polymer composites. In addition, using fully biodegradable polymer such as PLA and PHA made it sustainable and environmentally friendly.
Abstract: The goal of this study was to investigate the influence of cyclic hot and cold water absorption and desorption on the flexural and impact strengths of luffa – PLA biocomposites. PLA was reinforced with heat treated luffa fibers with the fiber loadings: 5 vol.%, 10 vol.%, 15 vol.% and 20 vol.%. Based on the test results the biocomposite with the highest flexural and impact strengths was selected for water absorption and desorption cycles. The biocomposites were subjected to 56 cycles of hot and cold water absorption and desorption. The biocomposites were tested for their strengths after every 14 cycles. The absorption and desorption decreased the flexural and impact strengths, affecting the impact strength more than the flexural strength.