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The effect of chitosan filled diglycidyl ether of bisphenol A (DGEBA) epoxy system were investigated using the thermal, mechanical, and morphological properties. The mixing ratio of resin/hardener was kept constant while the chitosan of 1.0, 2.5, 5.0, 7.5, and 10 weight percentage (wt%) was incorporated into the system. The thermal stability and the transition behaviour of the chitosan filled epoxy system were analysed through a differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) while atomic force microscope (AFM) and scanning electron microscopy (SEM) were used to investigate the morphology. It was observed that the additive tends to agglomerate, with the formation of clear phase separation, when the chitosan content increases above 5 wt%. At lower chitosan loading (2.5 wt% and below), relatively uniform dispersion of the additive can be achieved. The thermal stability of the system increases with chitosan loading while the mechanical tensile strength is compromised.

Hybrid polylactide acid (PLA) composites reinforced with palm empty fruit bunch (EFB) and chopped strand E-glass (GLS) fibres were investigated. The hybrid fibres PLA composite was prepared through solution casting followed by pelletisation and subsequent hot compression press into 1 mm thick specimen. Chloroform and dichloromethane were used as solvent and their effectiveness in dissolving PLA was reported. The overall fibre loading was kept constant at volume fraction, Vf, of 20% while the ratio of EFB to GLS fibre was varied between Vf of 0 : 20 to 20 : 0. The inclusion of GLS fibres improved the tensile and flexural performance of the hybrid composites, but increasing the glass fibre length from 3 to 6 mm has a negative effect on the mechanical properties of the hybrid composites. Moreover, the composites that were prepared using chloroform showed superior tensile and flexural properties compared to those prepared with dichloromethane.

Fuse deposition modelling (FDM) has become a revolutionary manufacturing technology as it offers numerous advantages, including freedom of fabrication, mass customisation, fast prototyping, and cost-effectiveness. Thermoplastic material is commonly used as feedstock for FDM process. The current state of material development, the recycled plastic material also can be used as printing material for FDM machine. Expanded polystyrene (EPS) has been extensively used as packaging materials for many industries but rarely be recycled, as its relatively large volume with minimal weight is unconducive for transportation. This research aimed to utilize EPS waste and turn it into FDM feedstock. This research also aims to enhance the properties of recycled polystyrene (rPS) made from EPS waste by blending it with polypropylene (PP). Different ratios of rPS/PP blends were prepared and extruded into FDM filament using filament extruder. The formulated filaments were printed into specimen using FDM machine. This research found the filament made from rPS/PP blends can be printed into specimen with good printing quality if the nozzle temperature controlled at 240° C with 120 % extrusion rate. With this printing parameter, the specimen printed with rPS/PP blend filament exhibit the greatest adhesion between the deposited layers without any visible voids or gaps. Besides, the printed specimen with rPS/PP blends possess lower tensile strength, but higher tensile modulus as compared to the printed specimen with neat rPS. The addition of more PP decreased both tensile strength and modulus of rPS/PP blends. On the other hand, the rPS/PP blends have higher thermal stability as the PP content increased. Overall, the rPS/PP blends filament shows a great potential as a feedstock material for FDM fabrication.

Styrofoam is widely used as packaging material for many applications like home furniture and electrical appliance. Styrofoam is a non-biodegradable material which its disposal causes serious environment issues. This research demonstrates an alternate recycling method of Styrofoam waste by converting it into 3D printing filament for Fused Deposition Modelling (FDM). For this research, the recycled polystyrene (rPS) was extracted from Styrofoam waste and blended with low-density polyethylene (LDPE), then extruded into filament using a filament extruder. The formulated rPS/LDPE blend with different blend ratio exhibited a good printability when the printing temperature and extrusion rate fixed at 240°C and 120%. However, the tensile strength of printed specimens with rPS/LDPE blends were lower than printed specimen with neat rPS. The tensile strength and modulus of printed specimens with rPS/LDPE were decreased due to the increase of LDPE content. The decrease of tensile strength mainly caused by the incompatibility between the rPS and LDPE phases. However, the addition of more LDPE content in the blend enhanced the ductility of rPS/LDPE blends. Furthermore, the increase of LDPE content also increased the thermal stability of rPS/LDPE blends. Overall, the rPS/LDPE blend is a potential alternate material for producing FDM filament.

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Electric Discharge Machining (EDM) process uses electrodes made from graphite that wear out over time and are turned into scrap. In this research, EDM electrode scraps were recycled and turned into graphite powder (rGP). This rGP was used as a conductive filler to produce conductive polymer composite (CPC) material by combining it with polypropylene (PP) resin via melt compounding and compression moulding processes. The percolation threshold of this composite material changed when 30 wt% of rGP was added, whereby the insulative material changed became antistatic. The composite was able to achieve surface resistivity as low as 105 ohm/sq. However, the addition of higher rGP content deteriorated the tensile properties of composite, whereby the tensile strength of composite significantly decreased as compared to neat PP. The results also showed that the tensile modulus of this composite became higher, and the material became more brittle as compared to neat PP. However, the PP/rGP composite with 50 wt% filler content reduced the tensile modulus due to plasticising effect caused by the agglomeration of rGP. The addition of high filler content on PP/rGP composite also caused an increase in processing torque. This was due to the restriction of rGP particles to the melt flow of molten PP. The morphological analysis found that the PP/rGP composites with higher amounts of filler content were highly agglomerated and formed conductivity paths within the PP matrix. The increase of rGP content highly improved the thermal stability of composite. The findings of this study show that the rGP has the potential to be used as a conductive filler for producing conductive composite material.

Abstract-The mechanical properties of varying percentage mass fraction, Mf, of empty fruit bunch (EFB) palm fibre/epoxy composite, ranging from 0 to 30% was investigated. A predefined weightage of loose EFB fibre was manually distributed within the effective area of the mould cavity surface. The fibre mat was subsequently wetted with epoxy and subjected to curing under compression. Enhancement was observed in the EFB loaded composite as compared to pure epoxy. Composite with 27% of EFB showed the greatest improvement in the measured tensile strength (14.8%) and Young's modulus (87%). However, there was a reduction in elongation at break with increasing fibre loading. Similar trend was observed for flexural test whereby the flexural strength and flexural modulus showed an increasing trend with the addition of EFB fibre.