Applied Mechanics and Materials Vols. 754-755

Abstract: Solid polymer electrolytes (SPEs) comprising of a blend of Poly (ethyl methacrylate) (PEMA) and Epoxidized natural rubber-50 (ENR50) as polymer host and lithium triflate (LiCF₃SO₃) as dopant were prepared by solution cast technique. The blend based polymer electrolytes have a fixed PEMA/ENR50 ratio of 70:30 by wt. % as at this ratio ENR-50 imparted stable mechanical properties to the otherwise fragile PEMA. The incorporation of LiCF₃SO₃ into the blend is found to increase the conductivity of PEMA/ENR50. The highest conductivity achieved was 3.64 x 10^-5 Scm^-1 at 40wt. % LiCF₃SO₃. The structure of the samples was investigated by X-ray diffraction and the results show that the highest conducting sample is the most amorphous.

Abstract: This research focused on the utilization of kapok husk (KH) as filler in low linear density polyethylene (LLDPE). The effect of filler content on tensile properties and morphology of LLDPE/KH eco-composites were investigated. The eco-composites were prepared by using Brabender Plasticiser EC Plus at temperature 160 °C and rotor speed 50 rpm. The results indicated that the tensile strength and elongation at break decreased with KH content increased. However, the modulus of elasticity increased with increasing of KH content. The morphology study of eco-composites exhibit poor interfacial adhesion between KH and LLDPE.

Abstract: The effect of Al particles addition on the microstructure and microhardness of Sn-0.7Cu-xAl lead-free solder was systematically investigated. The Sn-0.7Cu-xAl solder alloy was successfully fabricated via powder metallurgy (PM) method which consists of mixing, compaction and sintering. Results show that the crystallization of Sn occurs in two different modifications; α-Sn and β-Sn, where the formation of β-Sn able to reinforce the solder matrix. The Al particles also distributed homogeneously along the grain boundaries. The microhardness was improved by 19% as the weight percentage of the Al particles increased up to 1.0 wt.%.

Abstract: The widespread usage of commercial calcium oxide (CaO) may lead to the depletion due to its non-renewable resources. CaO from eggshell waste has been studied to replace commercial CaO as it is cheaper and reduce cost of production. The objective of this study was to characterize CaO from waste eggshell. Raw eggshell was analyzed by thermal gravimetric analyzer (TGA) to obtain calcination temperature. The raw eggshell and calcined eggshell were characterized by x-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscopy to obtain elemental composition and functional group distribution. The morphologies of eggshell structures were determined by scanning electron microscope (SEM). TGA showed that the suitable temperature for calcination was 900^oC. XRF and FTIR results showed that calcium carbonate (CaCO₃) in the raw eggshell had been transformed to CaO. The irregular shape of raw eggshell also had been changed to regular shape for calcined eggshell.

Abstract: Soy protein isolate (SPI)/kapok husk (KH) based biofilms were prepared by casting method. The effect of phthalic anhydride (PA) content on tensile properties and morphology were studied. The PA was use as a crosslink agent. It was found that the increasing PA content have increased the tensile strength and modulus of elasticity of biofilms, whereas the elongation at break decreased. At 1.5 % of PA showed the highest tensile strength and modulus of elasticity of crosslink biofilms. The morphology study indicates the crosslinking with PA improved the interfacial interaction between KH and SPI matrix.

Abstract: Powder metallurgy technique were proved successful net-shape technology which suitable for the production of steel parts characterised by good physical and mechanical properties of MMCs. The aim of this work is to study the effect of the sintering temperature with different volume ratio of natural carbon fibers reinforced copper-zinc alloy via powder metallurgy route. In this study, water hyacinth was used as a natural carbon fiber to replace tin element. The samples were mixed in different volume fraction of natural carbon fiber which is 0%, 5%, 10% and 15% in constant composition of copper alloy (70Cu/30Zn). The mixture was consolidated into rigid die compaction at 300MPa, then sintered at 400, 550 and 750°C respectively in the furnace under Argon atmospheric pressure at a flow rate of 50ml/min for 2h and cooled down naturally under Argon gas protection. Vickers hardness test were investigated. The composite were then characterized using optical microscope and scanning electron microscopy (SEM). The copper alloy composite reinforced with 10% carbon fiber at 550°C shows highest hardness strength which is about 112.0 HV.

Abstract: The effect of corn stalk content and compatibilizer on tensile properties and morphology of Low Density Polyethylene (LDPE)/Corn Stalk (CS) biocomposites was studied. The results found that the tensile strength and elongation at break decreased, but Young’s modulus increased with increasing CS content. The dispersion and interfacial adhesion between the CS filler and thermoplastic were important factors affecting the tensile properties of composites system. In order to improve the compatibility and interfacial adhesion, maleic anhydride polyethylene (MAPE) as compatibilizer was added into LDPE/CS biocomposites. The addition of MAPE has enhanced tensile properties and interfacial interaction between CS and LDPE biocomposites, as demonstrated in SEM study.

Abstract: Polymer blending is one of the methods used to improve some insufficient properties of conventional polymers. The objective of this work was to study the effectiveness of CR content on the tensile properties and morphology study of recycled polypropylene (rPP)/ chloroprene rubber (CR) blends. The results indicated that the tensile strength and modulus of elasticity of rPP/CR blends decreased, however elongation at break increased as increasing CR content. The morphology study of rPP/CR blends showed the incompatibility between rPP and CR with the detachment of CR particles and CR particles pulled out from rPP surface.

Abstract: The thermal degradation of high density polyethylene (HDPE)/ recycled acrylonitrile butadiene rubber (NBRr)/ banana skin powder (BSP) composites with and without ENR-50 are fabricated and studied. The thermal degradation of this composite was evaluated for 30 days oven ageing. The BSP with size of 150 – 300 μm was utilized in this work. All compounds were mixed using heated two roll mill at 180 °C. The compounds were molded in a hot press machine at 180 °C for 11 minutes to produce 1 mm thin sheet. Then the sheet were cut into dumbbell shape for the mechanical testing using universal testing machine. The tensile strength of high density polyethylene/ recycled acrylonitrile butadiene rubber/ banana skin powder composites showed the decreasing trend with the increasing NBRr loading for the composites with and without ENR-50. However, the result for the oven ageing showed lower tensile strength. This may due to the chain session of PP matrix at heat exposure duration of 30 days.

Abstract: The compatibilizer effect of ENR-50 on the tensile properties of high density polyethylene (HDPE)/recycled acrylonitrile butadiene rubber (NBRr)/banana skin powder (BSP)/ composites has been studies. HDPE/NBRr/BSP composites were prepared by melt mixing technique using twin-screw at 180 °C for 9 minutes at rotor speed 50 rpm. The six different composites studied were 100/0/5, 80/20/5, 70/30/5, 60/40/5, 50/50/5, and 40/60/5. As for compatibilized composite a fix 5 wt% of ENR-50 was evaluated. The specimens were analysed for tensile strength and elongation at break (E_b). The results showed that tensile strength and the elongation at break were decreases with the increasing of NBRr loading. However for ENR-50 compatibilized composites, higher tensile strength and elongation at break was recorded. The ENR-50 was found to be an excellent compatibilizer for HDPE/NBRr/BSP composites.