International journal of engineering and technology, 2015
The main objective of this research is to investigate the effect of dewaxing and burnout temperat... more The main objective of this research is to investigate the effect of dewaxing and burnout temperature on the quality of copper alloy casting produced by a low cost block mold that has been developed. In the molding process, two types of silica sand which contains 97.9% silica (SiO2) and 97.2% silica have been used as a refractory material with POP served as a binder. Several mold formulations contained 15-40% plaster of paris (POP), 60-85% silica sand and 35% water had been developed and each formulation had been tested in the process of copper alloy casting. In the dewaxing process, the temperature of 170 o C was found appropriate to be used as an initial mold heating temperature and complete wax burnout was effectively achieved with the temperature of 750 o C for 5 hours. The insufficient burnout process has produced a defect casting with carbon residue, appeared as a black stain on the surface of the casting. Meanwhile, rapid initial heating had prevented the wax from flowing out ...
The essence core of this study is to investigate the effect of functionalization of graphene plat... more The essence core of this study is to investigate the effect of functionalization of graphene platelets (GNPs) and its low loadings of 0.25, 0.50, 0.75, and 1.00 wt% on the chemical, mechanical, and electrical properties of polylactic acid/liquid natural rubber (PLA/LNR) blend prepared by melt blending method. GNPs are treated with amino dodecanoic acid via covalent interaction and Triton X‐100 (TX100) via non‐covalent interaction to produce ADA‐functionalized GNPs (GNP‐A) and TX100‐functionalized GNPs (GNP‐T), respectively. At 0.75 wt% GNPs, the PLA/LNR nanocomposites exhibit the highest tensile strength of 24.38, 35.70, 45.47 MPa for untreated GNPs (GNP‐u), GNP‐T, and GNP‐A, respectively. Variable pressure scanning electron microscopy proves better interaction of treated‐GNPs with the matrix, while transmission electron microscopy micrographs have shown that PLA/LNR/GNP‐A has the best filler dispersion with minimal stacking and agglomeration found. A remarkable improvement of elect...
The nanocomposites were prepared using melt intercalation technique in an internal mixer. Particu... more The nanocomposites were prepared using melt intercalation technique in an internal mixer. Particular attention was given to investigate the influence of different processing condition such as rotor speed and mixing time on the tensile properties and also phase morphology of the nanocomposites using SEM. The nanocomposites were prepared from blend of high density polyethylene (HDPE), natural rubber (NR) and organoclay. Significant improvement in tensile strength and modulus of composites were obtained with rotor speed at 80 rpm. While optimum mixing time used was 12 min. The morphology of the composites determined from the fracture surface of tensile specimen showed a large filler particle or agglomeration of organoclay in the blend at low rotor speed.
International Journal of Nano and Biomaterials, 2014
ABSTRACT Thermal and flexural properties of ternary system containing epoxy, poly(methyl methacry... more ABSTRACT Thermal and flexural properties of ternary system containing epoxy, poly(methyl methacrylate) (PMMA) grafted natural rubber, and organic chemically modified montmorillonite clay (Cloisite 30B) were studied. The results of TEM, SEM, XRD, FTIR, DSC, TGA and flexural tests were discussed. The rates of glass transition and decomposition process were introduced as relevant parameters to evaluate glass transition and thermal stability. It was observed that the addition of 5 phr Cloisite 30B in epoxy contributed to significant improvement in thermal properties and flexural modulus of nanocomposites. The intercalated structure of silicate clay may help to introduce tortuous path for volatiles to escape the epoxy network, hence retarding the decomposition process. The high char yield content for epoxy/clay and rubber toughened epoxy/clay nanocomposite show that they can be used as adhesive and coating materials with good thermal stability properties.
ABSTRACT Thermoplastic natural rubber (TPNR) as polymer matrix was prepared by the melt blending ... more ABSTRACT Thermoplastic natural rubber (TPNR) as polymer matrix was prepared by the melt blending method. Nickel-cobalt-zinc (NiCoZn) ferrite as a filler was prepared by the double-stage sintering method in air. The filler was incorporated in the polymer matrix ...
Thermoplastic natural rubber (TPNR) nanocomposites containing organophilic layered silicates were... more Thermoplastic natural rubber (TPNR) nanocomposites containing organophilic layered silicates were prepared by melt blending method at 180°C using internal mixer (Haake 600P). The aim of this study is to determine the influence of the organoclay filler on the mechanical and fracture properties. In this study, two mixing methods were employed to incorporate filler into matrix, namely the direct (DM) and indirect (IDM) method. The mechanical properties of TPNR nanocomposites were studied using tensile, flexural, and impact tests. The tensile and flexural tests revealed that the optimum loading of organoclay was at 4 wt% using the indirect method of mixing. Plane stress fracture toughness of thermoplastic natural rubber (TPNR) nanocomposite was determined by the essential work of fracture (EWF) concept using tensile-loaded deeply double-edge notched (DDEN-T) specimens. The EWF measurements indicated that the specific essential work of fracture (we) decreased in the presence of nanoclay. Nevertheless, these TPNR nanocomposites met the basic requirement of the EWF concept of full ligament yielding, which was marked by a load drop in the force—displacement curves of the DDEN-T specimens.
In the previous article, a diol‐based RBD palm kernel polyol was prepared. It has been found that... more In the previous article, a diol‐based RBD palm kernel polyol was prepared. It has been found that the polyurethane foam produced is only giving a good compressive strength property at 45 kg/m3 molded density. The combination of sorbitol into the polyol system resulted in a better dimensional stability and improved thermal conductivity as well as enhanced the compressive strength. These were obtained by increasing the functionality of the polyol (functionality of 4.5) through introduction of high molecular weight and branching polyhidric compound. Direct polycondensation and transesterification methods were used for the syntheses. The hydroxyl value, TLC, and the FTIR were determined to study the completion of the reaction. A comparative study of the mechanical properties and morphological behavior was carried out with the diol‐based polyol. From the water‐blown molded foam (zero ozone depletion potential ODP) with density of about 44.2 kg/m3 and closed‐cell content of 93%, it result...
The hybridization of thermoplastic natural rubber based on carbon fiber (CF) and kenaf fiber (KF)... more The hybridization of thermoplastic natural rubber based on carbon fiber (CF) and kenaf fiber (KF) was investigated for its mechanical and thermal properties. Hybrid composites were fabricated with a melt‐blending method in an internal mixer. Samples with overall fiber contents of 5, 10, 15, and 20 vol % were subjected to flexural testing, and samples with up to 30% fiber content were subjected to impact testing. For flexural testing, generally, the strength and modulus increased up to 15 vol % and then declined. However, for impact testing, higher fiber contents resulted in an increment in strength in both treated and untreated composites. Thermal analysis was carried out by means of dynamic mechanical analysis on composites with 15 vol % fiber content with fractions of CF to KF of 100/0, 70/30, 50/50, 30/70, and 0/100. Generally, the storage modulus, loss modulus, and tan δ for the untreated hybrid composite were more consistent and better than those of the treated hybrid composite...
International journal of engineering and technology, 2015
The main objective of this research is to investigate the effect of dewaxing and burnout temperat... more The main objective of this research is to investigate the effect of dewaxing and burnout temperature on the quality of copper alloy casting produced by a low cost block mold that has been developed. In the molding process, two types of silica sand which contains 97.9% silica (SiO2) and 97.2% silica have been used as a refractory material with POP served as a binder. Several mold formulations contained 15-40% plaster of paris (POP), 60-85% silica sand and 35% water had been developed and each formulation had been tested in the process of copper alloy casting. In the dewaxing process, the temperature of 170 o C was found appropriate to be used as an initial mold heating temperature and complete wax burnout was effectively achieved with the temperature of 750 o C for 5 hours. The insufficient burnout process has produced a defect casting with carbon residue, appeared as a black stain on the surface of the casting. Meanwhile, rapid initial heating had prevented the wax from flowing out ...
The essence core of this study is to investigate the effect of functionalization of graphene plat... more The essence core of this study is to investigate the effect of functionalization of graphene platelets (GNPs) and its low loadings of 0.25, 0.50, 0.75, and 1.00 wt% on the chemical, mechanical, and electrical properties of polylactic acid/liquid natural rubber (PLA/LNR) blend prepared by melt blending method. GNPs are treated with amino dodecanoic acid via covalent interaction and Triton X‐100 (TX100) via non‐covalent interaction to produce ADA‐functionalized GNPs (GNP‐A) and TX100‐functionalized GNPs (GNP‐T), respectively. At 0.75 wt% GNPs, the PLA/LNR nanocomposites exhibit the highest tensile strength of 24.38, 35.70, 45.47 MPa for untreated GNPs (GNP‐u), GNP‐T, and GNP‐A, respectively. Variable pressure scanning electron microscopy proves better interaction of treated‐GNPs with the matrix, while transmission electron microscopy micrographs have shown that PLA/LNR/GNP‐A has the best filler dispersion with minimal stacking and agglomeration found. A remarkable improvement of elect...
The nanocomposites were prepared using melt intercalation technique in an internal mixer. Particu... more The nanocomposites were prepared using melt intercalation technique in an internal mixer. Particular attention was given to investigate the influence of different processing condition such as rotor speed and mixing time on the tensile properties and also phase morphology of the nanocomposites using SEM. The nanocomposites were prepared from blend of high density polyethylene (HDPE), natural rubber (NR) and organoclay. Significant improvement in tensile strength and modulus of composites were obtained with rotor speed at 80 rpm. While optimum mixing time used was 12 min. The morphology of the composites determined from the fracture surface of tensile specimen showed a large filler particle or agglomeration of organoclay in the blend at low rotor speed.
International Journal of Nano and Biomaterials, 2014
ABSTRACT Thermal and flexural properties of ternary system containing epoxy, poly(methyl methacry... more ABSTRACT Thermal and flexural properties of ternary system containing epoxy, poly(methyl methacrylate) (PMMA) grafted natural rubber, and organic chemically modified montmorillonite clay (Cloisite 30B) were studied. The results of TEM, SEM, XRD, FTIR, DSC, TGA and flexural tests were discussed. The rates of glass transition and decomposition process were introduced as relevant parameters to evaluate glass transition and thermal stability. It was observed that the addition of 5 phr Cloisite 30B in epoxy contributed to significant improvement in thermal properties and flexural modulus of nanocomposites. The intercalated structure of silicate clay may help to introduce tortuous path for volatiles to escape the epoxy network, hence retarding the decomposition process. The high char yield content for epoxy/clay and rubber toughened epoxy/clay nanocomposite show that they can be used as adhesive and coating materials with good thermal stability properties.
ABSTRACT Thermoplastic natural rubber (TPNR) as polymer matrix was prepared by the melt blending ... more ABSTRACT Thermoplastic natural rubber (TPNR) as polymer matrix was prepared by the melt blending method. Nickel-cobalt-zinc (NiCoZn) ferrite as a filler was prepared by the double-stage sintering method in air. The filler was incorporated in the polymer matrix ...
Thermoplastic natural rubber (TPNR) nanocomposites containing organophilic layered silicates were... more Thermoplastic natural rubber (TPNR) nanocomposites containing organophilic layered silicates were prepared by melt blending method at 180°C using internal mixer (Haake 600P). The aim of this study is to determine the influence of the organoclay filler on the mechanical and fracture properties. In this study, two mixing methods were employed to incorporate filler into matrix, namely the direct (DM) and indirect (IDM) method. The mechanical properties of TPNR nanocomposites were studied using tensile, flexural, and impact tests. The tensile and flexural tests revealed that the optimum loading of organoclay was at 4 wt% using the indirect method of mixing. Plane stress fracture toughness of thermoplastic natural rubber (TPNR) nanocomposite was determined by the essential work of fracture (EWF) concept using tensile-loaded deeply double-edge notched (DDEN-T) specimens. The EWF measurements indicated that the specific essential work of fracture (we) decreased in the presence of nanoclay. Nevertheless, these TPNR nanocomposites met the basic requirement of the EWF concept of full ligament yielding, which was marked by a load drop in the force—displacement curves of the DDEN-T specimens.
In the previous article, a diol‐based RBD palm kernel polyol was prepared. It has been found that... more In the previous article, a diol‐based RBD palm kernel polyol was prepared. It has been found that the polyurethane foam produced is only giving a good compressive strength property at 45 kg/m3 molded density. The combination of sorbitol into the polyol system resulted in a better dimensional stability and improved thermal conductivity as well as enhanced the compressive strength. These were obtained by increasing the functionality of the polyol (functionality of 4.5) through introduction of high molecular weight and branching polyhidric compound. Direct polycondensation and transesterification methods were used for the syntheses. The hydroxyl value, TLC, and the FTIR were determined to study the completion of the reaction. A comparative study of the mechanical properties and morphological behavior was carried out with the diol‐based polyol. From the water‐blown molded foam (zero ozone depletion potential ODP) with density of about 44.2 kg/m3 and closed‐cell content of 93%, it result...
The hybridization of thermoplastic natural rubber based on carbon fiber (CF) and kenaf fiber (KF)... more The hybridization of thermoplastic natural rubber based on carbon fiber (CF) and kenaf fiber (KF) was investigated for its mechanical and thermal properties. Hybrid composites were fabricated with a melt‐blending method in an internal mixer. Samples with overall fiber contents of 5, 10, 15, and 20 vol % were subjected to flexural testing, and samples with up to 30% fiber content were subjected to impact testing. For flexural testing, generally, the strength and modulus increased up to 15 vol % and then declined. However, for impact testing, higher fiber contents resulted in an increment in strength in both treated and untreated composites. Thermal analysis was carried out by means of dynamic mechanical analysis on composites with 15 vol % fiber content with fractions of CF to KF of 100/0, 70/30, 50/50, 30/70, and 0/100. Generally, the storage modulus, loss modulus, and tan δ for the untreated hybrid composite were more consistent and better than those of the treated hybrid composite...
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