TS. DR. NORAZURA IBRAHIM | Universiti Teknologi Mara (original) (raw)
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Papers by TS. DR. NORAZURA IBRAHIM
International Journal of Adhesion and Adhesives, Feb 1, 2005
The availability of the coupling agent bis(3-triethoxysilylpropyl-)tetrasulphane (TESPT) has prov... more The availability of the coupling agent bis(3-triethoxysilylpropyl-)tetrasulphane (TESPT) has provided a better opportunity for using synthetic silicas to reinforce natural rubber. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulphur-cure. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica surfaces
Key Engineering Materials, 2021
Silicone rubber (SR) and hydroxyapatite (HA) are two well-known material that have been used as b... more Silicone rubber (SR) and hydroxyapatite (HA) are two well-known material that have been used as bone replacement. The flexibility and compatibility of SR and HA respectively, shows great performance and improvement in medical application. This paper investigate the mechanical properties of SR and HA composite with various phr loading of HA (0 - 30 phr). The results indicate that, HA loading phr of 25 phr and 30 phr were in the range of tensile strength of 5.76 MPa and 3.15 MPa respectively. Also, the hardness value of all the percentage loading of HA were above the hardness value of human vertebrae cancellous bone.
Rubber Chemistry and Technology, 2005
The effect of a large amount of precipitated amorphous white silica nanofiller, pre-treated with ... more The effect of a large amount of precipitated amorphous white silica nanofiller, pre-treated with bis[3-triethoxysilylpropyl-)tetrasulfide (TESPT), on the mechanical properties of a sulfur-cured natural rubber (NR) was studied. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulfur-cure. The silica particles were fully dispersed in the rubber, which was cured primarily by using sulfur in TESPT, or, by adding a small amount of elemental sulfur to the cure system. The cure was also optimized by incorporating sulphenamide accelerator and zinc oxide into the rubber. The hardness, tear strength, tensile strength, and stored energy density at break of the vulcanizate were substantially improved when the filler was added. Interestingly, these properties were also enhanced when the rubber was cured primarily by using sulfur in TESPT.
Numerous studies of polylactide (PLA) nanocomposites have been reported. However, the role and im... more Numerous studies of polylactide (PLA) nanocomposites have been reported. However, the role and importance of processing conditions in preparing the nanocomposites is the subject of very few papers. The effect of filler loadings on nanocomposites also has
AIP Conference Proceedings, 2018
Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all ... more Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all rice producing countries. Burning RH as fuel to generate energy would result in a waste product, rice husk ash (RHA). RHA contains approximately 90 – 98% of silica (SiO2), after undergoing a complete combustion process, which is the highest among other agricultural wastes. Silica is one of the commonly used fillers in natural rubber (NR). A chemical treatment for the RHA was developed to collect the silica, via a simple method consisting of alkaline extraction and acid precipitation. This method can produce finer and visually whiter RHA powder. The effects of the chemical treatment on the particle size and surface area of the silica particles were measured. The precipitated silica was then incorporated into NR, using a laboratory-size two-roll mill. For comparison, commercial silica was used as a control. The cure characteristics and mechanical properties of the vulcanizates were evaluated. It was found that the chemical treatment (digestion and precipitation) on RHA has resulted in a significant decrease in its particle size and increase in its specific surface area. However, the mechanical properties of the vulcanizates produced from the treated RHA were lower than that of the commercial silica.Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all rice producing countries. Burning RH as fuel to generate energy would result in a waste product, rice husk ash (RHA). RHA contains approximately 90 – 98% of silica (SiO2), after undergoing a complete combustion process, which is the highest among other agricultural wastes. Silica is one of the commonly used fillers in natural rubber (NR). A chemical treatment for the RHA was developed to collect the silica, via a simple method consisting of alkaline extraction and acid precipitation. This method can produce finer and visually whiter RHA powder. The effects of the chemical treatment on the particle size and surface area of the silica particles were measured. The precipitated silica was then incorporated into NR, using a laboratory-size two-roll mill. For comparison, commercial silica was used as a control. The cure characteristics and mechanical properties of the vulcanizates were evaluated. It was found that t...
Compounds of natural rubber filled with bamboo charcoal powder with and without the presence of b... more Compounds of natural rubber filled with bamboo charcoal powder with and without the presence of bonding agents were prepared with a laboratory-sized two-roll mill. The effects of the loading of the bamboo charcoal powder 10 to 50 parts per hundred rubber (phr) on the curing characteristics and mechanical properties were investigated. For the sake of comparison, unfilled natural rubber was processed under the same conditions. The results indicate that the addition of bamboo charcoal powder in the natural rubber resulted in higher Mooney viscosity. Furthermore, the tensile modulus, hardness, and abrasion resistance of the vulcanizates showed great improvement with the increase of bamboo charcoal powder loading. The effective role of hexamethylene as a bonding agent resulted in shorter curing time, increase in tensile modulus, and elastic characteristics as compared to without the use of the bonding agent. The overall results indicate that bamboo charcoal powder could be used as filler...
Numerous studies of polylactide nanocomposites have been conducted. However, the role and importa... more Numerous studies of polylactide nanocomposites have been conducted. However, the role and importance of processing conditions is the subject of very few papers. In this work, polylactide and a constant amount (2 %w/w) of organoclay Cloisite® 30B via melt intercalation technique were produced. It is generally believed that maximum benefits are achieved when organoclay is well dispersed in PLA matrix. Experimental design was carried out based on Box-Behnken methods, a response surface methodology (RSM) well suited to the goal of process optimisation. Three levels of processing temperature, rotor speed and mixing time were chosen in this study. The response was Young's modulus. The interaction effects with the most influence on the Young's modulus of these PLA/organoclay nanocomposites are temperature and speed. Understanding the influence of processing conditions on the mechanical properties is needed for improving nanocomposites properties.
Over the last few years, polymer/layered silicate (PLS) nanocomposites have been an area of inten... more Over the last few years, polymer/layered silicate (PLS) nanocomposites have been an area of intense academic and industrial research. The combination of polymer and clays, at the nanoscale, often results in remarkably improved mechanical and functional properties, even at low filler concentration (1-5 wt%) with respect to pure polymers or conventional composites (either micro- or macrocomposites). In this study, PLA/organoclay nanocomposites were prepared by means of a melt blending method. The novel contribution of this study is the optimisation of processing conditions by using statistical analysis. The experiments were statistically designed and carried out according to a 23full factorial design with two replicate. The variables chosen for this study were mixing temperature, mixing speed and mixing time. Results showed that the optimum settings are 195 C for mixing temperature, 100 rpm for mixing speed and 5 min for mixing time. It is quite interesting to notice that the optimal ...
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. Content from this work may be used under th... more View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Numerous studies of polylactide nanocomposites have been conducted. However, the role and importa... more Numerous studies of polylactide nanocomposites have been conducted. However, the role and importance of processing conditions is the subject of very few papers. In this work, polylactide and a constant amount (2 %w/w) of organoclay Cloisite ® 30B via melt intercalation technique were produced. It is generally believed that maximum benefits are achieved when organoclay is well dispersed in PLA matrix. It might be anticipated that melt processing conditions would have an important influence on the nanocomposites formed. Experimental design was carried out based on Box-Behnken methods, a response surface methodology (RSM) well suited to the goal of process optimisation. Three levels of processing temperature, rotor speed and mixing time were chosen in this study. The response was Young's modulus. The interaction effects with the most influence on the Young's modulus of these PLA/organoclay nanocomposites are temperature and speed. The maximum Young's modulus was predicted t...
This work studied the improvement of poly (lactic acid) (PLA) properties by adding propylene-ethy... more This work studied the improvement of poly (lactic acid) (PLA) properties by adding propylene-ethylene copolymer (PEC) and α-cellulose (AC). The PLA blends and composites were melt mixed by an internal mixer and molded by compression method. The morphological analysis observed the phase separation of PLA/PEC blends due to minor PEC phase dispersed as spherical shape in PLA phase, indicating a poor interfacial adhesion between PLA and PEC phases. The incorporation of AC did not improve the compatibility of polymer blends. Young’s modulus and tensile strength of PLA blends reduced with increasing amount of PEC because the elastics of ethylene molecules in PEC structure. Young’s modulus of PLA/PEC/AC composites increased with increasing AC contents. The stress at break of the PLA/PEC blends was improved with the presence of AC. The strain at break of PLA/PEC blends increased with increasing PEC contents, and the presence of AC showed the decrease of strain at break of PLA/PEC blends.
International Journal of Adhesion and Adhesives, Feb 1, 2005
The availability of the coupling agent bis(3-triethoxysilylpropyl-)tetrasulphane (TESPT) has prov... more The availability of the coupling agent bis(3-triethoxysilylpropyl-)tetrasulphane (TESPT) has provided a better opportunity for using synthetic silicas to reinforce natural rubber. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulphur-cure. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica surfaces
Key Engineering Materials, 2021
Silicone rubber (SR) and hydroxyapatite (HA) are two well-known material that have been used as b... more Silicone rubber (SR) and hydroxyapatite (HA) are two well-known material that have been used as bone replacement. The flexibility and compatibility of SR and HA respectively, shows great performance and improvement in medical application. This paper investigate the mechanical properties of SR and HA composite with various phr loading of HA (0 - 30 phr). The results indicate that, HA loading phr of 25 phr and 30 phr were in the range of tensile strength of 5.76 MPa and 3.15 MPa respectively. Also, the hardness value of all the percentage loading of HA were above the hardness value of human vertebrae cancellous bone.
Rubber Chemistry and Technology, 2005
The effect of a large amount of precipitated amorphous white silica nanofiller, pre-treated with ... more The effect of a large amount of precipitated amorphous white silica nanofiller, pre-treated with bis[3-triethoxysilylpropyl-)tetrasulfide (TESPT), on the mechanical properties of a sulfur-cured natural rubber (NR) was studied. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulfur-cure. The silica particles were fully dispersed in the rubber, which was cured primarily by using sulfur in TESPT, or, by adding a small amount of elemental sulfur to the cure system. The cure was also optimized by incorporating sulphenamide accelerator and zinc oxide into the rubber. The hardness, tear strength, tensile strength, and stored energy density at break of the vulcanizate were substantially improved when the filler was added. Interestingly, these properties were also enhanced when the rubber was cured primarily by using sulfur in TESPT.
Numerous studies of polylactide (PLA) nanocomposites have been reported. However, the role and im... more Numerous studies of polylactide (PLA) nanocomposites have been reported. However, the role and importance of processing conditions in preparing the nanocomposites is the subject of very few papers. The effect of filler loadings on nanocomposites also has
AIP Conference Proceedings, 2018
Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all ... more Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all rice producing countries. Burning RH as fuel to generate energy would result in a waste product, rice husk ash (RHA). RHA contains approximately 90 – 98% of silica (SiO2), after undergoing a complete combustion process, which is the highest among other agricultural wastes. Silica is one of the commonly used fillers in natural rubber (NR). A chemical treatment for the RHA was developed to collect the silica, via a simple method consisting of alkaline extraction and acid precipitation. This method can produce finer and visually whiter RHA powder. The effects of the chemical treatment on the particle size and surface area of the silica particles were measured. The precipitated silica was then incorporated into NR, using a laboratory-size two-roll mill. For comparison, commercial silica was used as a control. The cure characteristics and mechanical properties of the vulcanizates were evaluated. It was found that the chemical treatment (digestion and precipitation) on RHA has resulted in a significant decrease in its particle size and increase in its specific surface area. However, the mechanical properties of the vulcanizates produced from the treated RHA were lower than that of the commercial silica.Rice husk (RH) is a hard shell that protects the rice grain and can be found in abundance in all rice producing countries. Burning RH as fuel to generate energy would result in a waste product, rice husk ash (RHA). RHA contains approximately 90 – 98% of silica (SiO2), after undergoing a complete combustion process, which is the highest among other agricultural wastes. Silica is one of the commonly used fillers in natural rubber (NR). A chemical treatment for the RHA was developed to collect the silica, via a simple method consisting of alkaline extraction and acid precipitation. This method can produce finer and visually whiter RHA powder. The effects of the chemical treatment on the particle size and surface area of the silica particles were measured. The precipitated silica was then incorporated into NR, using a laboratory-size two-roll mill. For comparison, commercial silica was used as a control. The cure characteristics and mechanical properties of the vulcanizates were evaluated. It was found that t...
Compounds of natural rubber filled with bamboo charcoal powder with and without the presence of b... more Compounds of natural rubber filled with bamboo charcoal powder with and without the presence of bonding agents were prepared with a laboratory-sized two-roll mill. The effects of the loading of the bamboo charcoal powder 10 to 50 parts per hundred rubber (phr) on the curing characteristics and mechanical properties were investigated. For the sake of comparison, unfilled natural rubber was processed under the same conditions. The results indicate that the addition of bamboo charcoal powder in the natural rubber resulted in higher Mooney viscosity. Furthermore, the tensile modulus, hardness, and abrasion resistance of the vulcanizates showed great improvement with the increase of bamboo charcoal powder loading. The effective role of hexamethylene as a bonding agent resulted in shorter curing time, increase in tensile modulus, and elastic characteristics as compared to without the use of the bonding agent. The overall results indicate that bamboo charcoal powder could be used as filler...
Numerous studies of polylactide nanocomposites have been conducted. However, the role and importa... more Numerous studies of polylactide nanocomposites have been conducted. However, the role and importance of processing conditions is the subject of very few papers. In this work, polylactide and a constant amount (2 %w/w) of organoclay Cloisite® 30B via melt intercalation technique were produced. It is generally believed that maximum benefits are achieved when organoclay is well dispersed in PLA matrix. Experimental design was carried out based on Box-Behnken methods, a response surface methodology (RSM) well suited to the goal of process optimisation. Three levels of processing temperature, rotor speed and mixing time were chosen in this study. The response was Young's modulus. The interaction effects with the most influence on the Young's modulus of these PLA/organoclay nanocomposites are temperature and speed. Understanding the influence of processing conditions on the mechanical properties is needed for improving nanocomposites properties.
Over the last few years, polymer/layered silicate (PLS) nanocomposites have been an area of inten... more Over the last few years, polymer/layered silicate (PLS) nanocomposites have been an area of intense academic and industrial research. The combination of polymer and clays, at the nanoscale, often results in remarkably improved mechanical and functional properties, even at low filler concentration (1-5 wt%) with respect to pure polymers or conventional composites (either micro- or macrocomposites). In this study, PLA/organoclay nanocomposites were prepared by means of a melt blending method. The novel contribution of this study is the optimisation of processing conditions by using statistical analysis. The experiments were statistically designed and carried out according to a 23full factorial design with two replicate. The variables chosen for this study were mixing temperature, mixing speed and mixing time. Results showed that the optimum settings are 195 C for mixing temperature, 100 rpm for mixing speed and 5 min for mixing time. It is quite interesting to notice that the optimal ...
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. Content from this work may be used under th... more View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Numerous studies of polylactide nanocomposites have been conducted. However, the role and importa... more Numerous studies of polylactide nanocomposites have been conducted. However, the role and importance of processing conditions is the subject of very few papers. In this work, polylactide and a constant amount (2 %w/w) of organoclay Cloisite ® 30B via melt intercalation technique were produced. It is generally believed that maximum benefits are achieved when organoclay is well dispersed in PLA matrix. It might be anticipated that melt processing conditions would have an important influence on the nanocomposites formed. Experimental design was carried out based on Box-Behnken methods, a response surface methodology (RSM) well suited to the goal of process optimisation. Three levels of processing temperature, rotor speed and mixing time were chosen in this study. The response was Young's modulus. The interaction effects with the most influence on the Young's modulus of these PLA/organoclay nanocomposites are temperature and speed. The maximum Young's modulus was predicted t...
This work studied the improvement of poly (lactic acid) (PLA) properties by adding propylene-ethy... more This work studied the improvement of poly (lactic acid) (PLA) properties by adding propylene-ethylene copolymer (PEC) and α-cellulose (AC). The PLA blends and composites were melt mixed by an internal mixer and molded by compression method. The morphological analysis observed the phase separation of PLA/PEC blends due to minor PEC phase dispersed as spherical shape in PLA phase, indicating a poor interfacial adhesion between PLA and PEC phases. The incorporation of AC did not improve the compatibility of polymer blends. Young’s modulus and tensile strength of PLA blends reduced with increasing amount of PEC because the elastics of ethylene molecules in PEC structure. Young’s modulus of PLA/PEC/AC composites increased with increasing AC contents. The stress at break of the PLA/PEC blends was improved with the presence of AC. The strain at break of PLA/PEC blends increased with increasing PEC contents, and the presence of AC showed the decrease of strain at break of PLA/PEC blends.