77 results on '"Wan Aizan Wan Abdul Rahman"'
Search Results
2. The Influence of Crosslink Chemicals on the Mechanical Strength and Water Absorption of Rice Straw-Based Green Composites
- Author
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Jiun Hor Low, Nurnadia Andenan, and Wan Aizan Wan Abdul Rahman
- Subjects
crosslink chemicals ,high density polyethylene ,mechanical strength ,polymer composites ,rice straw ,water absorption ,Science ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
The present work reports the influence of crosslink chemicals (vinyltrimethoxylsilane, dicumyl peroxide, and dibutyl dilaurate) on the mechanical strength and water absorption of the rice straw/high density polyethylene bio-composites. As revealed by the Fourier transform infrared spectra, the surface interaction between the fibers and polymer was improved through the use of vinyltrimethoxylsilane (coupling agent). By properly regulating the dicumyl peroxide (radical initiator) and dibutyl dilaurate (catalyst), the surface interaction was further enhanced, and thus the tensile and flexural strength. These observations were validated by the reduction in the water absorption of the bio-composites as well as the fracture surface examination.
- Published
- 2018
- Full Text
- View/download PDF
3. Preparation and Characterization of Cassava Leaves/ Cassava Starch Acetate Biocomposite Sheets
- Author
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Noor Fadzliana Ahmad Sharif, Saiful Izwan Abd Razak, Wan Aizan Wan Abdul Rahman, Nadirul Hasraf Mat Nayan, Abdul Razak Rahmat, and Mohd Yazid Yahya
- Subjects
Cassava leaves ,Tapioca ,Packaging ,Starch acetate ,Impregnation ,Moisture absorption ,Mercerization ,Biotechnology ,TP248.13-248.65 - Abstract
Biocomposite packaging sheets made of cassava leaves (CL) and cassava starch acetate (CSA) were successfully prepared in this study, and using the surface impregnation method, the sheets were able to obtain desirable properties. The CL sheets were impregnated with CSA at various concentrations to improve the sheets’ performance. This newly developed packaging material exhibited low moisture uptake and had a viable tear index value when the CSA impregnation level was 6%. Moreover, the sheets’ properties were comparable to that of available paper or plastic sheets, having low moisture uptake, good wetting time and tear strength, smooth sheet formation, and enhanced thermal stability. Using agro-based materials from cassava plants for packaging materials could reduce the dependency on paper- and plastic-based packaging. Suitable utilization of this material includes as bag, carton and wrap.
- Published
- 2015
- Full Text
- View/download PDF
4. CRUDE PALM OIL AS A BIOADDITIVE IN POLYPROPYLENE BLOWN FILMS
- Author
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Emiliana Rose Jusoh,, Mohd Halim Shah Ismail,, Luqman Chuah Abdullah,, Robiah Yunus,, and Wan Aizan Wan Abdul Rahman
- Subjects
Bio-additives ,Crude palm oil ,Polypropylene ,Blown film ,Mechanical properties ,Twin screw extruder ,Biotechnology ,TP248.13-248.65 - Abstract
Growing public concern about environment and potential risks to health in the polymer and plasticizer industry promises to increase the market for a safer alternative plasticizer such as a vegetable oil-based agent. The purpose of this study was to investigate the potential of crude palm oil as a bio-additive in polypropylene blown films. The polypropylene was blended with 1%, 3%, and 5% dosages of CPO using a twin screw extruder. The extruded samples were blown using the blown thin film technique. Mechanical, physical, and morphological properties were characterized. Modifying polypropylene with CPO showed good enhancement in the mechanical properties of the polypropylene. Tensile strength, elongation at break, impact strength, and tear strength all increased. The scanning electron microscopy photographs of the CPO-modified PP clearly supported the results from the mechanical strength tests. The presence of CPO in the PP matrices decreased the density and increased the melt flow rate. These findings contribute new knowledge to the additives area and give important implications for designing and manufacturing polymer packaging materials.
- Published
- 2012
5. Rice waste–based polymer composites for packaging applications: A review
- Author
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Wan Aizan Wan Abdul Rahman and Waham Ashaier Laftah
- Subjects
Materials science ,Polymers and Plastics ,Bran ,Cellulosic ethanol ,Composite number ,Materials Chemistry ,Ceramics and Composites ,Polymer composites ,Rice straw ,Straw ,Pulp and paper industry ,Husk - Abstract
Rice wastes are abundant, low-cost, cellulosic-based materials. The potential of using rice waste such as husk, straw, and bran in bio-composite production is a crucial target of the composite industry. Chemical composition is the main factor that offers diverse possible applications of rice wastes in bio-composite-based materials. Eco-friendly products of bio-composite polymers can be produced by reinforcing and filling polymer matrices with high cellulosic content materials such as rice waste. From manufacturing point of view, rice wastes can be used to reduce the production cost of polymer-based products and meet the requirements for green packaging materials.
- Published
- 2021
6. Effects of extraction method on dry pulp yield and morphological properties of pineapple leaf fibre
- Author
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Dayangku Intan Munthoub, Lai Jau Choy, Rohah A. Majid, Lew Jin Hau, and Wan Aizan Wan Abdul Rahman
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Retting ,Wax ,Scanning electron microscope ,General Mathematics ,Pulp (paper) ,General Physics and Astronomy ,General Chemistry ,engineering.material ,Pulp and paper industry ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,chemistry ,Sodium hydroxide ,visual_art ,engineering ,visual_art.visual_art_medium ,Lignin ,Fiber ,General Agricultural and Biological Sciences ,Natural fiber - Abstract
Pineapple leaves (PALs) are useful agro wastes which have the potentials to be used as an alternative source of non-wood natural fiber. In this study, different extraction methods had been investigated to identify the most feasible pineapple leaf fiber (PALF) extraction method, based on the dry pulp yield and the PALF morphology. The manual retting using a ceramic scrapper led to low yield of around 1.8 % (wt.), while water retting for 21 d led to about 6.0 % (wt.) yield of dark greenish dry pulp. Both methods resulted in PALFs which still contained with non-cellulosic residues, as verified by scanning electron microscopic (SEM) imaging. The chemical extraction of PALF using various NaOH solution concentrations (i.e. 1 to 20 % (wt.)) gave different yields. Based on the SEM images, clean and smooth surfaces of fibrils were observed when the NaOH solution concentrations applied at or higher than 6 % (wt.), implying that all impurities including lignin and wax had been completely removed. The mechanical-chemical extraction method produced significantly more dry pulp compared to the chemical extraction method at the same NaOH solution concentration. This is attributed to the fact that the crushed PAL has a larger surface area, thus providing more reaction possibilities with NaOH solution. Finally, it was found that the crushed PAL that cooked at 90 °C needed at least 90 min of cooking time to obtain satisfying whitish dry pulp.
- Published
- 2020
7. Preparation and Characterization of Hybrid Composite Film Based on Synthetic and Natural Materials
- Author
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Wan Aizan Wan Abdul Rahman and Waham Ashaier Laftah
- Subjects
Low-density polyethylene ,chemistry.chemical_compound ,Absorption of water ,Materials science ,Calcium carbonate ,chemistry ,Starch ,Scanning electron microscope ,Particle ,Biodegradation ,Composite material ,Amorphous solid - Abstract
Low density polyethylene / tapioca starch (LDPE/TS) blends have respectable biodegradation properties and poor mechanical and thermal properties compared to neat LDPE film. The focal target of this study is to investigate the effect of calcium carbonate (CaCO3) loading on mechanical, thermal, and biodegradation properties of LDPE/TS film. LDPE/TS/CaCO3 blend films were prepared using film blown processing. The results indicated that the maximum loading of CaCO3 which feasible to be incorporated into (45:20) LDPE/TS blend is 10% without exertions during film processing. CaCO3 has remarkable effect on mechanical properties of LDPE/TS films in both machine direction (MD) and cross direction (CD). Water absorption capacities of the films were reduced after the addition of CaCO3. Differential scanning analysis shows that more amorphous regions were generated in the blend structure after the addition of CaCO3 into the blend. Scanning Electron Microscope (SEM) analysis indicated a significant distribution of starch and CaCO3 particle in LDPE matrix, wherever the size of starch particles seems to be bigger than the size of CaCO3 particle.
- Published
- 2019
8. Effects of filler calcination on structure and dielectric properties of polyethylene/silica nanocomposites
- Author
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Noraiham Mohamad, Kwan Yiew Lau, Wan Aizan Wan Abdul Rahman, Nor Asiah Muhamad, N. H. Rahim, and Alun S. Vaughan
- Subjects
Permittivity ,Filler (packaging) ,Nanocomposite ,Materials science ,Dielectric ,Polyethylene ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,Molecule ,Calcination ,Electrical and Electronic Engineering ,Dc breakdown strength - Abstract
This paper reports on an investigation of the effects of calcination on the structure and dielectric properties of polyethylene/silica (SiO 2 ) nanocomposites. Calcination temperatures of 600 and 900 °C have been used in order to modify the surface chemistry and surface structure of the SiO 2 . The results show that, after calcination, the concentration of surface hydroxyl groups and water molecules around SiO 2 and within resulting nanocomposites is reduced. The real permittivity of nanocomposites containing calcined SiO 2 decreases compared to nanocomposites based on uncalcined SiO 2 . The DC breakdown strength of nanocomposites containing calcined SiO 2 becomes higher than those containing uncalcined SiO 2 . In contrast, AC breakdown was found not to be significantly affected by addition of any of the silicas considered here. The use of calcined nanofillers can have positive effects akin to the use of chemically functionalized nanofillers in enhancing the dielectric properties of nanocomposites; both approaches remove polar surface hydroxyl groups.
- Published
- 2019
9. Properties Characterization of Napier Grass (Pennisetum Purpureum) as the Non-wood Substitution for Natural Fiber Papermaking
- Author
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Wan Aizan Wan Abdul Rahman, Hooi Peng Lim, and Jiun Hor Low
- Subjects
Agronomy ,biology ,Chemistry ,Papermaking ,Substitution (logic) ,Pennisetum purpureum ,biology.organism_classification ,Natural fiber - Published
- 2020
10. Preparation and Characterization of Kenaf Papers Reinforced with Tapioca Starch: Physicomechanical and Morphological Properties
- Author
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Rohah A. Majid, Wan Aizan Wan Abdul Rahman, Taravat Ghanbari, and Jiun Hor Low
- Subjects
Tapioca starch ,Zirconium ,Materials science ,biology ,Starch ,Materials Science (miscellaneous) ,05 social sciences ,Modulus ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Kenaf ,Characterization (materials science) ,chemistry.chemical_compound ,chemistry ,0502 economics and business ,Ultimate tensile strength ,Fiber ,Composite material ,0210 nano-technology ,050203 business & management - Abstract
The present study reports the preparation and characterization of kenaf papers that reinforced with tapioca starch by using the ammonium zirconium (IV) carbonate as coupling agent. The examination shows the tearing resistance, tensile strength, and Young’s modulus of the kenaf papers are enhanced with the addition of starch and coupling agent, up to 3% and 1%, respectively. Under the optimum formulation, the degree of coupling reaction is 87%. The Fourier transform infrared and morphological analyses confirm the performance enhancement of kenaf papers is achieved via the formation of chemical bonding between the kenaf fiber and tapioca starch.
- Published
- 2017
11. The Influence of Crosslink Chemicals on the Mechanical Strength and Water Absorption of Rice Straw-Based Green Composites
- Author
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Jiun Hor Low, Nurnadia Andenan, and Wan Aizan Wan Abdul Rahman
- Subjects
0106 biological sciences ,chemistry.chemical_classification ,Materials science ,Absorption of water ,Materials Science (miscellaneous) ,02 engineering and technology ,Polymer ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,chemistry ,Flexural strength ,010608 biotechnology ,Mechanical strength ,Ultimate tensile strength ,Radical initiator ,High-density polyethylene ,Composite material ,0210 nano-technology - Abstract
The present work reports the influence of crosslink chemicals (vinyltrimethoxylsilane, dicumyl peroxide, and dibutyl dilaurate) on the mechanical strength and water absorption of the rice straw/high density polyethylene bio-composites. As revealed by the Fourier transform infrared spectra, the surface interaction between the fibers and polymer was improved through the use of vinyltrimethoxylsilane (coupling agent). By properly regulating the dicumyl peroxide (radical initiator) and dibutyl dilaurate (catalyst), the surface interaction was further enhanced, and thus the tensile and flexural strength. These observations were validated by the reduction in the water absorption of the bio-composites as well as the fracture surface examination.
- Published
- 2017
12. Optical properties of conjugated polymer: review of its change mechanism for ionizing radiation sensor
- Author
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Wan Aizan Wan Abdul Rahman, Naurah Mat Isa, Ruzalina Baharin, and Rohah A. Majid
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Nanotechnology ,02 engineering and technology ,Polymer ,Conjugated system ,Radiation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Ionizing radiation ,chemistry ,Nano ,Molecule ,sense organs ,0210 nano-technology ,Anisotropy ,Macromolecule - Abstract
A review on the change mechanism of conjugated polymer upon radiation exposure is presented. The change mechanism is mainly focused on the polymer's optical properties instead of its electrical properties. This research explores the effect of ionizing radiation on the optical change of conjugated polymer. This study also reviewed the possibility of using conjugated polymer as a radiation sensor vis-a-vis radiation type and the optical response. From material point of view, topochemical reaction, conjugation length and the degree of anisotropy of the conjugated polymer itself were identified as factors affecting the polymer's optical properties. These factors are tunable to meet a required optical degree, thus making the observation using the optical properties of a conjugated polymer possible for a radiation sensing tool. Based on the review, alteration of the factors and its mechanism of change occurs at macromolecular level. Therefore, a material at its smallest size down to a single molecule could be possible for the indication of radiation. Thus, radiation sensor made of nano or micro colloidal conjugated polymer deserves attention for future development. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
13. Optimization of Pineapple Leaf Fibre Extraction Methods and Their Biodegradabilities for Soil Cover Application
- Author
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S. Sarah, Rohah A. Majid, Wira Jazair Yahya, Jiun Hor Low, Nadia Adrus, A.K. Hasannuddin, and Wan Aizan Wan Abdul Rahman
- Subjects
Retting ,Environmental Engineering ,Materials science ,Polymers and Plastics ,Starch ,Extraction (chemistry) ,food and beverages ,02 engineering and technology ,Biodegradation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Kappa number ,Pulp and paper industry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Botany ,Materials Chemistry ,Lignin ,Soil fertility ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Cellulosic natural fibres from pineapple leaves are considered as a green alternative to the conventional polyethylene (PE) soil cover in agro-industry. The use of pineapple leaf fibres (PALFs) soil cover can overcome the disposal problem of the conventional plastic covers which take hundreds of years to degrade. This research was undertaken to study the effectiveness methods of extracting the PALFs. The mechanical method utilized ‘roller and bladder system’, where the chemical method involved the extraction with 6% NaOH, 20% aqueous acetone, and pineapple juice solution. The semi-mechanical method was a combination of “roller and bladder” system and a chemical retting process using 6% NaOH alkaline solutions. The characteristics of the extracted fibers were determined using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Kappa number test of the fibres extracted with semi-mechanical method showed the lowest percentage of lignin (3.39%). Based on XRD results, the highest percentage of crystallinity was recorded when PALF was extracted using the semi-mechanical method. A remarkable change on the morphological surface the biodegraded PALF soil cover was observed after 90 days of soil burial test. Biodegradability of soil cover made from PALF was higher than the commercial degradable soil cover i.e. PE/starch (80 wt% PE/ 20 wt% starch). Meanwhile, the growing rate and the soil fertility of chili tree that used PALFs soil cover showed better results than the chili tree that used conventional PE/starch soil cover.
- Published
- 2017
14. DC Breakdown Performance of Polyethylene/Silicon Nitride Nanocomposites upon Non-isothermal Crystallization
- Author
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Kwan Yiew Lau, Wan Aizan Wan Abdul Rahman, S. N. H. Kamarudin, Chee Wei Tan, and N. H. Rahim
- Subjects
010302 applied physics ,Materials science ,Nanocomposite ,Polymer nanocomposite ,Scanning electron microscope ,technology, industry, and agriculture ,02 engineering and technology ,Polyethylene ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Differential scanning calorimetry ,Silicon nitride ,chemistry ,Chemical engineering ,law ,0103 physical sciences ,Fourier transform infrared spectroscopy ,Crystallization ,0210 nano-technology - Abstract
For last decades, the topic of polymer nanocomposites have been widely studied in the scientific literature since the material system promises a substantial dielectric properties enhancement even at low nanoparticles loading. Nevertheless, factors contributing to increased or decreased DC breakdown strength of nanocomposites are far from understood. In this paper, an investigation on the DC breakdown strength of polyethylene nanocomposites that contained different amounts of silicon nitride with different non-isothermal crystallization processes is reported. The non-isothermal crystallization techniques were determined by fast, medium and slow cooling rate conditions by the differential scanning calorimetry (DSC) for all the nanocomposite samples. The chemical structures of the nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy and the morphology of the nanocomposites was determined by scanning electron microscopy (SEM). From DC breakdown testing, the breakdown results of the nanocomposites were found to vary under different non-isothermal crystallization conditions.
- Published
- 2018
15. Effect of Nanofiller Calcination on Breakdown Performance of Silica Based Polyethylene Nanocomposites
- Author
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Wan Aizan Wan Abdul Rahman, Noraiham Mohamad, Nor Asiah Muhamad, Kwan Yiew Lau, S. N. H. Kamarudin, and N. H. Rahim
- Subjects
010302 applied physics ,Materials science ,Nanocomposite ,Polymer nanocomposite ,02 engineering and technology ,Dielectric ,Polyethylene ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Dielectric spectroscopy ,chemistry.chemical_compound ,chemistry ,law ,0103 physical sciences ,Calcination ,Cubic zirconia ,Composite material ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Polymer nanocomposites have become one of the main research studies in investigating the potential use of new dielectric materials especially in high voltage insulation. Many promising results, especially on the use of polyethylene nanocomposites as dielectric materials, have been reported in the literature. Significantly, the main factor that affects the dielectric performance of the materials was attributed to the interface between the host matrix and the nanofiller. This paper reports on an investigation into the AC and DC breakdown performance of unfilled and polyethylene nanocomposites containing silicon dioxide (SiO2) nanofillers at different loading levels (1 wt%, 4 wt%, and 8wt%). By using the Fourier transform infrared (FTIR) spectroscopy, the chemical structures of the materials were characterized. The dielectric permittivity of the samples was analyzed using dielectric spectroscopy. From the breakdown results, it showed that AC breakdown testing did not result in significant changes on the breakdown strength between uncalcined and calcined nanofillers. Meanwhile, for DC breakdown testing, introducing a small number of nanofillers could have a major impact on the DC breakdown strength. These results were correlated with the calcination process of nanofiller; the DC breakdown strength improved for calcined nanofiller compared to uncalcined nanofiller.
- Published
- 2018
16. AC Breakdown Performance of Non-isothermally Crystallized Polyethylene/Silicon Nitride Nanocomposites
- Author
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Wan Aizan Wan Abdul Rahman, Kwan Yiew Lau, N. H. Rahim, S. N. H. Kamarudin, and Chee Wei Tan
- Subjects
010302 applied physics ,chemistry.chemical_classification ,Nanocomposite ,Materials science ,Polymer nanocomposite ,Silicon ,technology, industry, and agriculture ,chemistry.chemical_element ,02 engineering and technology ,Polymer ,Polyethylene ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Silicon nitride ,law ,0103 physical sciences ,Composite material ,Crystallization ,0210 nano-technology - Abstract
Polymer nanocomposites has a huge potential to serve as dielectric materials. These materials were found to have a great capability in withstanding high voltage levels. In nanocomposites development, the breakdown strength of the materials was often reported to be higher, lower or similar, in comparison with the unfilled polymer. Because of this, the breakdown performance of nanocomposites is said to be dependent not only on the polymer/nanofiller combination, but also on the sample preparation techniques. Unfortunately, factors leading to increased or decreased the breakdown strength of nanocomposites are less understood. In this paper, investigation into polyethylene blend systems that contain different amounts of silicon nitrite nanofiller with different non-isothermal crystallization processes was reported. The non-isothermal crystallization techniques were determined by fast, medium and slow cooling rate conditions while preparing the samples. Differential scanning calorimetry (DSC) was used to characterize the thermal behavior of the polymer nanocomposites. The AC breakdown data showed that the use of different non-isothermal crystallization techniques affected the AC breakdown strength of each material type.
- Published
- 2018
17. Thermal and Breakdown Properties of Polypropylene Homopolymer, Copolymer, and Blend
- Author
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Aizat Azmi, Wan Aizan Wan Abdul Rahman, Noor Azlinda Ahmad, Kwan Yiew Lau, and Zulkurnain Abdul-Malek
- Subjects
010302 applied physics ,Polypropylene ,Materials science ,High voltage ,Calorimetry ,01 natural sciences ,Space charge ,010305 fluids & plasmas ,Characterization (materials science) ,chemistry.chemical_compound ,Thermal conductivity ,chemistry ,0103 physical sciences ,Thermal ,Copolymer ,Composite material - Abstract
Polypropylene has been widely used in high voltage insulation. This material has recently been regarded as to potentially compensate conventional limitations of XLPE such as being difficult to recycle and having significant space charge accumulation and poor thermal conductivity. Currently, there are various types of polypropylene produced in the market. Therefore, this research attempts to investigate the breakdown performance of several types of polypropylene, namely, polypropylene homopolymer, polypropylene impact copolymer, and the combination of both in 50:50 ratio. The thermal behaviors of the samples were characterized using scanning calorimetry (DSC). The thermal characterization demonstrates that all types of polypropylene have a similar melting temperature of about 162 °C. Besides that, the breakdown test reveals that polypropylene homopolymer has the highest DC breakdown of 278 kV/mm. Meanwhile, polypropylene impact copolymer has the lowest breakdown strength of 109 kV/mm and 239 kV/mm under the applied AC and DC fields, respectively.
- Published
- 2018
18. Pulping Process and the Potential of Using Non-Wood Pineapple Leaves Fiber for Pulp and Paper Production: A Review
- Author
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Wan Aizan Wan Abdul Rahman and Waham Ashaier Laftah
- Subjects
0106 biological sciences ,Materials science ,Materials Science (miscellaneous) ,Pulp (paper) ,Paper production ,02 engineering and technology ,engineering.material ,Raw material ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,01 natural sciences ,chemistry.chemical_compound ,chemistry ,Cellulosic ethanol ,010608 biotechnology ,engineering ,Cellulose ,0210 nano-technology ,High potential ,Renewable resource - Abstract
The main objective of this article is to investigate the potential of using pineapple leaves as non-wood materials for paper production. The chemical compositions of non-wood raw materials and the advantages and disadvantages of different pulping methods were reviewed. The advantages of solvent pulping process over other techniques in terms of scale production, water, energy and chemicals consumption, and pulp quality might be the driving forces of using this process in future production of pulps from pineapple leaves waste. Pineapple leaves are cellulosic, abundance agro-waste of pineapple industries with chemical composition of high cellulose contents. Good mechanical properties, renewable resource, and low cost fibers are the main factors that lead to high potential of pineapple leaves’ fibers to be used as alternative raw materials in paper industries.
- Published
- 2015
19. The influence of extraction parameters on spent coffee grounds as a renewable tannin resource
- Author
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Jamarosliza Jamaluddin, Jiun Hor Low, and Wan Aizan Wan Abdul Rahman
- Subjects
chemistry.chemical_classification ,Engineering ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,Strategy and Management ,Extraction (chemistry) ,Raw material ,Left behind ,Industrial and Manufacturing Engineering ,Renewable energy ,chemistry.chemical_compound ,Coffee grounds ,chemistry ,Sodium hydroxide ,Tannin ,Brewing ,business ,General Environmental Science - Abstract
Spent coffee grounds that are left behind during the coffee brewing process consist of valuable tannin compounds which makes them ideal material as a renewable tannin resource. For this reason, the concept of cleaner production had been applied in practice and a tannin extraction process with spent coffee grounds as raw material was investigated in the present study. Among the extraction key factors, namely sodium hydroxide concentration, extraction temperature, liquid to solid ratio, and extraction time, the former three factors had exerted a considerable effect on spent coffee ground tannin extraction yield and its reactivity. However, extraction time had only marginal effects which could be simply neglected in the tannin extraction process. These observations imply that spent coffee grounds can be reused as a renewable tannin resource by properly selecting the extraction parameters in order to produce the spent coffee ground tannin with desirable extraction yield and reactivity. By taking both the spent coffee ground tannin extraction yield and reactivity into consideration, the optimum extraction conditions are; 5% sodium hydroxide concentration, 100 °C extraction temperature, 30 min extraction time, and 8.23 liquid to solid ratio, so that tannin with a high extraction yield (21.02%) and high reactivity (29.69%) could be recovered. The present study provides an understanding on the impact of the extraction parameters on isolated spent coffee ground tannin as well as to fill up academic deficiencies in spent coffee grounds, which, in turn, could serve as a reliable guideline for the development of a full-scale, sustainable spent coffee ground tannin extraction process in coffee industries.
- Published
- 2015
20. Structural elucidation of tannins of spent coffee grounds by CP-MAS 13C NMR and MALDI-TOF MS
- Author
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Wan Aizan Wan Abdul Rahman, Jamarosliza Jamaluddin, and Jiun Hor Low
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chemistry.chemical_classification ,Matrix-assisted laser desorption/ionization ,chemistry.chemical_compound ,Monomer ,chemistry ,Magic angle spinning ,Gallocatechin ,Organic chemistry ,Tannin ,Catechin ,Carbon-13 NMR ,Agronomy and Crop Science ,Chebulic acid - Abstract
In this study, carbon-13 nuclear magnetic resonance in the solid state using cross-polarization and magic angle spinning (CP-MAS 13C NMR) spectroscopic and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometric methods were applied to characterize the composition, constituent monomer and oligomeric structure of tannins of spent coffee grounds (SCG). The findings elucidated that the monomeric constituents of tannins of SCG primarily composed of catechin, gallocatechin, chebulic acid, gallocatechin-3-O-gallate and accompanied by minor amount of fisetinidin concurrently. Appreciable amount of catechin was found among the observed components. Hence, this simply implied that catechin was the main substructure of the tannins of SCG. It is expected that the present findings will serve as a platform towards a structural understanding of tannins of SCG in filling up the gaps in the field of study of SCG, and simultaneously promoting the use of SCG as a renewable resource for tannins.
- Published
- 2015
21. Effect of Plasticizers on Tapioca Starch-Based Biofilms via Blown Film Extrusion Process
- Author
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Norazana Ibrahim, Roshafima Rasit Ali, Wan Aizan Wan Abdul Rahman, Umi Aisah Asli, Rafiziana Md. Kasmani, Aziatul Niza Sadikin, and Hasrinah Hasbullah
- Subjects
chemistry.chemical_classification ,Materials science ,Starch ,General Engineering ,Plasticizer ,food and beverages ,Polymer ,chemistry.chemical_compound ,Low-density polyethylene ,Viscosity ,chemistry ,Glycerol ,Extrusion ,Composite material ,Melt flow index - Abstract
In this study, a series of tapioca starch-based low density polyethylene (LDPE) biofilms were prepared via extrusion process and further using blown film extrusion with various contents of starch. Various contents of glycerol and palm oil based olein as plasticizers, both ranging from 5 wt% to 20 wt% were added to blends. The starch-based LDPE blends were undergo the melt flow index analysis to study its processability before further process by film blowing extrusion. Both film blowing ability and melt indexes displayed the effect of both plasticizers in starch-based LDPE blends. Starch based LDPE biofilms with addition of 5 wt% palm oil based glycerin show large influence on the shear viscous properties of starch polymer melts compared to glycerol. Palm oil based glycerin would decrease the viscosity of starch polymer melt since it can decrease the polymer entanglement density and increase the ease of disentanglement.
- Published
- 2015
22. Microbial study of pH sensitive starch based film using agar diffusion method (zone inhibition assay)
- Author
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Bazlul Mobin Siddique, Ida Idayu Muhamad, Wan Aizan Wan Abdul Rahman, and Nozieana Khairuddin
- Subjects
Food packaging ,chemistry.chemical_compound ,Colourant ,chemistry ,Methyl red ,Bromothymol blue ,Active packaging ,Food science ,Agar diffusion test ,Bacterial growth ,Thymol - Abstract
Active and smart packaging is a promising form of food packaging that offers a great economical potential due to consumer demand for a packaging that accommodate a hectic way of life. An antimicrobial film with pH colour indicator (pHF) can be made by incorporating suitable antimicrobial (AM) agent and colour indicator into food package matrices whilst applying a bio switch concept to inhibit the pathogenic microorganisms and respond automatically to changes (external stimuli) in the environment. The present work aimed to study the developed formulation of hydroxyethylcellulose (HEC)/wheat-starch based pHF film in which the active compound, thymol (0.5, 1, 1.5, 2, and 2.5% w/w) and 50:50% w/w bromothymol blue and methyl red (as the colour indicator) against microbial growth. A solution casting method was used in the film preparation while thymol and colourant were incorporated prior to casting. The effect of thymol showed a range of microbial inhibition zones of 16.3 - 26.4% and 22.1 - 39.9% towards E. coli and B. subtilis, respectively. Whilst, a lower inhibition zone of 0.4 - 5.1% was demonstrated for fungus A. niger.
- Published
- 2019
23. PALF/skin extracted pineapple juice: New potential as pulping and bleaching agent in papermaking and its effect on mechanical and physical properties
- Author
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Siti Noorashikin Jamal, Noor Aishatun Majid, Sharifah Nafisah Syed Ismail, and Wan Aizan Wan Abdul Rahman
- Subjects
Paper sheet ,stomatognathic diseases ,Residue (complex analysis) ,Tear resistance ,chemistry.chemical_compound ,Absorption of water ,Chemistry ,Sodium hydroxide ,Papermaking ,Ultimate tensile strength ,food and beverages ,Pulp and paper industry ,PINEAPPLE JUICE - Abstract
Pineapple has been known for a number of beneficial biological activities such as anti-oxidative and anti-browning. Some of these bioactivities are contributed by enzymatic complex in pineapple and it can be found mainly in the skin extracted pineapple juice. The purpose of this study is to determine the effect of the pineapple juice as a pulping and bleaching agent in the process of papermaking. During pulping of pineapple leaf fibre, the mixture of pineapple juice/water was added together with a constant amount of 3% Sodium Hydroxide (NaOH) at various concentration of pineapple juice (0%, 20%, 40%, 60% and 80%). Pineapple leaf fibre (PALF) was soaked several times with pineapple juice and NaOH during pulping and bleaching process in order to get the optimum results of the paper sheet obtained. The mechanical and physical properties of paper sheet were studied by measuring its tensile strength, tear resistance and water absorption. Comparatively, paper sheet produced from NaOH pulping shows better mechanical and physical properties than the mixture pulping of NaOH and pineapple juice. Additionally, pulping with higher concentration of pineapple juice tends to give long fibre rather than short fibre. Overall, the results of this study can be used as an alternative way in the production of paper and it also opens a door to utilize wisely the waste residue of pineapple in other sectors.
- Published
- 2018
24. Studies on blow ability of cassava starch-LDPE composite using glycerol and palm olein as plasticizer for green biofilm production
- Author
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Norazana Ibrahim, Roshafima Rasit Ali, Aziatul Niza Sadikin, Mohd Shahrul Nizam Salleh, Kamyar Shameli, Wan Aizan Wan Abdul Rahman, Rafiziana Md. Kasmani, Hasrinah Hasbullah, and Nurfatehah Wahyuny Che Jusoh
- Subjects
Palm olein ,chemistry.chemical_compound ,Low-density polyethylene ,Materials science ,chemistry ,Starch ,Composite number ,Biofilm ,Glycerol ,Plasticizer ,Food science - Published
- 2018
25. Effects of SiO2 and ZrO2 on the AC breakdown performance of polyethylene
- Author
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Nor Asiah Muhamad, Wan Aizan Wan Abdul Rahman, Noraiham Mohamad, Kwan Yiew Lau, and N. H. Rahim
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,Filler (packaging) ,Materials science ,Differential scanning calorimetry ,Nanocomposite ,chemistry ,Polymer nanocomposite ,Dielectric strength ,Polymer ,Dielectric ,Composite material ,Polyethylene - Abstract
In electrical insulation, polymer nanocomposites become one of the main research areas for exploring the potential of insulating materials in terms of dielectric strength enhancement. This is due to many promising results of nanocomposites reported by the dielectrics community. For this, the interfaces between the filler and base polymer is one of the major factors for improving the filler/ polymer interaction within the nanocomposites. This paper reports on an investigation into the AC breakdown performance of unfilled and nanofilled polyethylene. With different nanofillers (silicone dioxide (SiO 2 ) and zirconium oxide (ZrO 2 )) and different loading levels (1 wt%, 4 wt%, 8 wt%). The thermal behavior of the materials was characterized using differential scanning calorimetry (DSC) and the melting traces for the materials were determined. The breakdown results showed that a low nanofiller loading level (1 wt%) did not significantly affect the breakdown strength compared to the unfilled sample. When comparing samples containing SiO 2 and ZrO 2 nanofillers, it appeared that those with ZrO 2 filler had slightly higher breakdown strength compared to those containing SiO 2 nanofiller. The significance of the results is discussed.
- Published
- 2017
26. The effect of non-isothermal crystallization on the AC breakdown performance of polyethylene/silicon dioxide nanocomposites
- Author
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Kwan Yiew Lau, S. N. H. Kamarudin, and Wan Aizan Wan Abdul Rahman
- Subjects
chemistry.chemical_classification ,Materials science ,Nanocomposite ,Polymer nanocomposite ,High voltage ,Dielectric ,Polymer ,Polyethylene ,law.invention ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,law ,Crystallization ,Composite material - Abstract
Increasing demands in high voltage applications result in the need to design new electrical insulation systems. For this reason, polymer nanocomposites have recently been actively studied. In the dielectrics community, polymer nanocomposites refer to polymer matrices incorporating nanometer-sized fillers as a means for enhancing the dielectric properties. These materials were found to have a great capability in withstanding high voltage levels such as those required in high voltage alternating current (HVAC) and high voltage direct current (HVDC) applications. This paper reports on an investigation into polyethylene systems that contains different amounts of nanosilica with different non-isothermal crystallization processes. The non-isothermal crystallization techniques were determined by fast, medium and slow cooling rate conditions while preparing the samples. The thermal behavior of the polymer nanocomposites was characterized by differential scanning calorimetry. The breakdown results showed that the use of different non-isothermal crystallization techniques affected the breakdown strength of the same material type.
- Published
- 2017
27. Thermal Properties Determination of Polypropylene/Rice Straw Biocomposite Foam via TGA
- Author
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Nazuha Tugiman, Zurina Mohamad, and Wan Aizan Wan Abdul Rahman
- Subjects
General Medicine - Abstract
Polymer foam biocomposites based on polypropylene/rice straw (PP/RS) were successfully prepared by using an extrusion foaming process. The compounding of PP and RS was performed in a twin-screw extruder which was blended with crosslinker; dicumyl peroxide (DCP) and blowing agent; azodicarbonamide (AZ). The foam biocomposite was extruded at temperatures of 180, 190, 190 and 200 °C respectively, which set from the feeder until the die zone. The thermal properties were investigated by using thermal gravimetric analysis (TGA).
- Published
- 2014
28. Thermal Properties Determination of Polypropylene/Rice Straw Biocomposite Foam via DSC
- Author
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Nazuha Binti Tugiman, Wan Aizan Wan Abdul Rahman, and Zurina Mohamad
- Subjects
Polypropylene ,chemistry.chemical_compound ,Materials science ,Differential scanning calorimetry ,Azodicarbonamide ,chemistry ,Blowing agent ,Plastics extrusion ,Extrusion ,Thermal stability ,General Medicine ,Biocomposite ,Composite material - Abstract
Polymer foam biocomposites based on polypropylene/rice straw (PP/RS) were successfully prepared by using an extrusion foaming process. The compounding of PP and RS was performed in a twin-screw extruder which was blended with crosslinker; dicumyl peroxide (DCP) and blowing agent; azodicarbonamide (AZ). The foam biocomposite was extruded at temperatures of 180, 190, 190 and 200 °C respectively, which set from the feeder until the die zone. The thermal properties were investigated by using differential scanning calorimetry (DSC).
- Published
- 2014
29. Biopulping by Ceriporiopsis subvermispora towards Pineapple Leaf Fiber (PALF) Paper Properties
- Author
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Nadirul Hasraf Mat Nayan, Saiful Izwan Abd Razak, and Wan Aizan Wan Abdul Rahman
- Subjects
Chemical pulping ,Materials science ,Pulp (paper) ,General Engineering ,engineering ,engineering.material ,Ceriporiopsis subvermispora ,Pulp and paper industry - Abstract
Environmental awareness and depletion of the wood resources are among vital factors that motivate various researchers to explore the potential of agro-based crops as an alternative source of fiber material in paper industries such as writing, printing, wrapping, and packaging. Fibers from agro-based crops are available in abundance, low cost, and most importantly its biodegradability features, which sometimes referred as “ecofriendly” materials. This paper reports the biopulping of pineapple leaf fiber (PALF) by Ceriporiopsis subvermispora towards the properties of its fiber and paper forms. The individual fibers were characterized having good tensile properties at 0.3% of fungus treatment and favourable structural properties as characterized by Fourier transform infra-red (FTIR) spectroscopy. It was also shown that the PALF paper achieved desirable tear index value and uniform morphological observations compared to the conventional chemical pulping method. This new approach of pulping PALF finds applications in paper and packaging products which requires biofriendly characteristic and cost effective.
- Published
- 2014
30. Biofilm Green Packaging: Characterization and Biodegradation Studies
- Author
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Hasrinah Hasbullah, Roshafima Rasit Ali, Rafiziana Md. Kasmani, Wan Aizan Wan Abdul Rahman, Aziatul Niza Sadikin, and Norazana Ibrahim
- Subjects
chemistry.chemical_compound ,Low-density polyethylene ,Materials science ,chemistry ,Starch ,Ultimate tensile strength ,Extrusion ,General Medicine ,Polyethylene ,Composite material ,Biodegradation ,Tensile testing ,Melt flow index - Abstract
Normal 0 false false false EN-MY X-NONE X-NONE MicrosoftInternetExplorer4 The LDPE was blended with various contents of tapioca starch (10%, 20%, 30%, and 40%) with addition of compatibilizer, which is PE-g-MA and cooking oil as plasticizer. The blends were prepared by co-rotating twin screw extrusion process and characterized by melt flow index (MFI) analysis and tensile test. Tapioca starch based polyethylene biofilms were studied in term of biodegradability by fungi test. The increasing of starch content to LDPE blend was reduced the MFI values and tensile strength but in 30% and 40% of starch content in tensile strength is higher than control LDPE’s strength due to molecular orientation in sample. However, incorporation of PE-g-MA as compatibiliz increase the mechanical properties of starch based polyethylene blends due to the reaction between maleated PE and starch, thus improves adhesion and reduces slippage at matrix-filler interface.ers The increasing of TS also increase the water content in film sample, weight loss percentage in TGA, and percentage degradation of LDPE/TS blend film. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}
- Published
- 2014
31. The influence of polyvinyl acetate and rice starch binders on molded rice straw filled rice bran: comparative study
- Author
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Waham Ashaier Laftah and Wan Aizan Wan Abdul Rahman
- Subjects
Paper sheet ,Absorption of water ,Polyvinyl acetate ,Polymers and Plastics ,Bran ,Starch ,Metals and Alloys ,food and beverages ,Rice straw ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Thermal stability ,Food science ,Fiber - Abstract
The main objective of this study is to evaluate the effect of rice starch and polyvinyl acetate (PVAc) as binding agents on mechanical, thermal and water absorption properties of molded rice bran/rice straw (RB/RS). Rice bran (RB) and rice straw (RS) were molded in form of paper sheet using compression-molding technique. Tearing resistance of RB/RS was enhanced by 135%–140% after the addition of PVA and rice starch binders. Thermal stability of RB/RS was affected positively by PVAc and negatively by rice starch binders. Fractured surface analysis of inverted optical microscope indicated that RB/RS samples have clear visible phase separation without binding agent compared to RB/RS with binders of PVAc and rice starch.
- Published
- 2019
32. Studies on Blow Ability of Cassava Starch-LDPE Composite using Glycerol and Palm Olein as Plasticizer for Green Biofilm Production.
- Author
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Ali, Roshafima Rasit, Nurfatehah Wahyuny Che Jusoh, Shameli, Kamyar, Wan Aizan Wan Abdul Rahman, Sadikin, Aziatul Niza, Hasbullah, Hasrinah, Kasmani, Rafiziana Md., Ibrahim, Norazana, and Mohd Shahrul Nizam Salleh
- Subjects
CASSAVA starch ,LOW density polyethylene ,PALM oil ,GLYCERIN ,PLASTICIZERS - Abstract
This study aims to produce cassava starch (CS) based low density polyethylene (LDPE) biofilms with the addition of glycerol and palm olein as processing aids. Prior to blown film extrusion the CS-LDPE composite was prepared via blown film extrusion process. The composites were formulated with the addition of polyethylene-graftedmaleic anhydride (PE-g-MA) as a compatibilizer. The flow ability analysis of the produced CS-LDPE biofilms was conducted using melt flow indexer. The biofilms with addition of fixed amounts of palm oil based olein displayed excellent film blowing ability compared to glycerol. In addition, incorporating of CS to the biofilms significantly lower the physical-mechanical properties of the final products. This is due to the poor interfacial adhesion between starch and synthetic polymer. The melt index of CS-LDPE biofilms noted a significant decreasing trend caused by the incorporation of starch and plasticizers in the blends for both, glycerol and palm oil based glycerin. Scanning electron micrograph (SEM) of this biofilm with starch composition up to 30 wt% showed good dispersion of starch granular in the polymer matrix. SEM also found the images of starch particles seem to be embedded in the LDPE matrix. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Mechanical, thermal and water absorption properties of plasticised sago pith waste
- Author
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Jau Choy Lai, Wen Yee Toh, and Wan Aizan Wan Abdul Rahman
- Subjects
chemistry.chemical_classification ,Thermogravimetric analysis ,Thermoplastic ,Materials science ,Absorption of water ,Polymers and Plastics ,Starch ,General Chemical Engineering ,Plasticizer ,General Chemistry ,Polyvinyl alcohol ,chemistry.chemical_compound ,chemistry ,Ultimate tensile strength ,Extrusion ,Composite material - Abstract
This paper provides an insight into the potential of utilising sago pith waste (SPW) to produce composite material. SPW is a fibrous waste that is produced as a result of the sago starch extraction process. It is made up of more than 60 % in weight of sago starch and was successfully converted into natural fibre reinforced thermoplastic starch composite using twin screw extrusion in the presence of different quantities of glycerol and water as plasticisers. No binder was added throughout the process. Good fibre-matrix compatibility was proven by SEM. Due to phase separation and fibre agglomeration, tensile strength of the composite decreased with increasing glycerol content while elongation at break remained unchanged at low values. Activation energies, Ea of the composites were computed from thermogravimetric analysis (TGA) data using Broido and Coat-Redfern equations. The obtained Ea values indicated that plasticisation led to the reduction in thermal resistance of SPW. It is suggested that blending the plasticised SPW with sago starch and polyvinyl alcohol will greatly improve upon the existing shortcomings, potentially resulting in useful consumer products from SPW, an unutilised, water polluting waste.
- Published
- 2014
34. Effects of Kenaf core on properties of poly(lactic acid) bio-composite
- Author
-
Nazila Dehbari, Nima Moazeni, and Wan Aizan Wan Abdul Rahman
- Subjects
Materials science ,Absorption of water ,Polymers and Plastics ,biology ,Composite number ,General Chemistry ,Biodegradation ,biology.organism_classification ,Kenaf ,Flexural strength ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,Extrusion ,Thermal stability ,Composite material - Abstract
In this study, biodegradable poly(lactic acid) (PLA)/Kenaf core composites with different amount of Kenaf core were prepared using screw extrusion. The Structure, thermal stability, mechanical properties, and biodegradation of bio-composites are evaluated. FTIR result shows the possible interaction between the Ken core and PLA matrix. The FESEM result showed that Kenaf core was uniformly disperse in PLA matrix. Tensile and flexural strength of PLA was improved Up to the 30%vol of kenaf core content. Young's modulus and hardness properties were improved by adding kenaf core into PLA matrix. Bio-composite density has been decreased by adding more kenaf core and water absorption of the compound was increased linear. High Kenaf core content was also found to increase the rate of biodegradability of PLA/kenaf core. It can be proven by exposure of the samples to the environment and weight loss in soil burial analysis. POLYM. COMPOS., 35:1220–1227, 2014. © 2013 Society of Plastics Engineers
- Published
- 2013
35. Para-Hydroxybenzene Sulfonic Acid as a Suitable Dopant for the Preparation of Conductive Epoxy/Polyaniline Nanowires Nanocomposites Blend: Electrical vs Mechanical Properties
- Author
-
Saiful Izwan Abd Razak, Mohd Yazid Yahya, and Wan Aizan Wan Abdul Rahman
- Subjects
chemistry.chemical_classification ,Nanocomposite ,Materials science ,Polymers and Plastics ,Dopant ,General Chemical Engineering ,Materials Science (miscellaneous) ,Nanowire ,Epoxy ,Sulfonic acid ,chemistry.chemical_compound ,chemistry ,Electrical resistivity and conductivity ,visual_art ,Polyaniline ,Materials Chemistry ,visual_art.visual_art_medium ,Composite material ,Electrical conductor - Abstract
This article reports improved mechanical properties of epoxy/polyaniline nanowires nanocomposite (EP/PANI) by using para-hydroxybenzene sulfonic acid as the dopant. The PANI nanowires show no chain dedoping in the EP. Mechanical properties of the nanocomposites were maintained while achieving its conductive state and revealed pull-out of bundles rather than individual nanowire.
- Published
- 2013
36. Polyaniline-coated kenaf core and its effect on the mechanical and electrical properties of epoxy resin
- Author
-
Muhammad Akmal Ahmad Saidi, Saiful Izwan Abd Razak, Nadirul Hasraf Mat Nayan, Mohd Yazid Yahya, Noor Fadzliana Ahmad Sharif, and Wan Aizan Wan Abdul Rahman
- Subjects
Materials science ,biology ,Composite number ,General Physics and Astronomy ,Epoxy ,biology.organism_classification ,Kenaf ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Flexural strength ,Polymerization ,Electrical resistivity and conductivity ,visual_art ,Polyaniline ,Ultimate tensile strength ,Ceramics and Composites ,visual_art.visual_art_medium ,Composite material - Abstract
Novel conducting kenaf core/polyaniline (KC-PANI) biofibers were successfully prepared via in situ oxidative polymerization. The newly developed conducting KC achieved enhancement in DC conductivity up to seven fold compared to the raw KC. Enhanced interaction was obtained between the acetylated KC-PANI surfaces compared to untreated KC-PANI, without significant loss in the cellulose crystallinity. The morphological analysis revealed uniform layers of PANI deposited on the surface of acetylated KC. Epoxy resin (EP) containing KC-PANI (EP/KC-PANI composites) showed that the electrical percolation of KC-PANI occurred at 20 wt.%. The tensile strength of the EP/KC-PANI composites was slightly reduced compared to that of EP/KC composites at the same loading fraction. However, the flexural test revealed that the presence of KC-PANI increased the flexural strength of the EP composites by up to 15 wt.% loading. Electron micrograph of the EP/KC-PANI composite indicated favourable adhesion between components.
- Published
- 2013
37. Hybrid composites of short acetylated kenaf bast fiber and conducting polyaniline nanowires in epoxy resin
- Author
-
Saiful Izwan Abd Razak, Wan Aizan Wan Abdul Rahman, and Mohd Yazid Yahya
- Subjects
Materials science ,biology ,Mechanical Engineering ,Percolation threshold ,Epoxy ,biology.organism_classification ,Kenaf ,chemistry.chemical_compound ,chemistry ,Flexural strength ,Mechanics of Materials ,visual_art ,Polyaniline ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Bast fibre ,Fiber ,Composite material - Abstract
This article reports the preparation and characterization of newly developed hybrid composites consisting of epoxy resin (EP) matrix, acetylated kenaf bast fiber (AKF) and conducting polyaniline (PANI) nanowires. Initially, the EP/AKF composites were prepared by varying the AKF loading (5–30 wt%). The EP/AKF displayed an optimum tensile strength at 20 wt% AKF loading which was higher than that of untreated kenaf fiber EP composites (EP/UKF). The hybrid composites of EP/AKF/PANI were then prepared by using 20 wt% AKF loading with PANI inclusions from 2 to 14 wt%. The addition of PANI into EP/AKF induced positive electrical properties without considerably sacrificing its mechanical integrity. It was found that the electrical percolation threshold of these hybrid composites was at 11 wt% of PANI loading. PANI inclusions at above the percolation loading resulted in reduction of tensile and flexural strength. Meanwhile, no significant mechanical loss was observed below the threshold. The fracture morphological analysis revealed the occurrences of PANI nanowires pull out from the matrix. The Fourier transform infrared spectroscopy showed that the PANI component still maintained its doped condition inside the EP/20AKF. Water absorption and thermal analysis indicate that the PANI incorporation induced lower water uptakes and greater thermal stability to the EP/20AKF, respectively.
- Published
- 2013
38. Characterisation of sago pith waste and its composites
- Author
-
Wan Aizan Wan Abdul Rahman, Wen Yee Toh, and Jau Choy Lai
- Subjects
chemistry.chemical_classification ,Materials science ,Thermoplastic ,Starch ,Plasticizer ,food and beverages ,chemistry.chemical_compound ,Crystallinity ,chemistry ,Chemical engineering ,Amylose ,Amylopectin ,Botany ,Pith ,Fourier transform infrared spectroscopy ,Agronomy and Crop Science - Abstract
Sago pith waste (SPW), a fibrous residue resulted from the sago starch extraction process, was characterised in terms of moisture content (82%) and starch content (62%, dry weight basis). The dried and ground SPW was irregular in shape and has a CE diameter of 29.41 μm, similar to that of pure sago starch (28.43 μm). SEM micrograph showed that SPW is a mixture which consists of sago starch and fibre, verified by FTIR spectrum and XRD diffractogram observed from peaks which were attributed to sago starch and SPW fibre. With glycerol and water as plasticisers, SPW was then plasticised successfully to form a natural fibre filled thermoplastic starch composite using a twin screw extruder in the presence of various quantities of glycerol. No synthetic polymer binder was added. Plasticisation led to the disruption of the original C-type crystallinity of sago starch. However, V H and B type crystallinities were developed after processing as a result of the reorganisation of amylose, amylose–lipid complex (very fast) and amylopectin chains (slow).
- Published
- 2013
39. Enhanced Interfacial Interaction and Electronic Properties of Novel Conducting Kenaf/Polyaniline Biofibers
- Author
-
Saiful Izwan Abd Razak, Shahrir Hashim, Wan Aizan Wan Abdul Rahman, and Mohd Yazid Yahya
- Subjects
Materials science ,Polymers and Plastics ,biology ,General Chemical Engineering ,Materials Science (miscellaneous) ,Doping ,engineering.material ,biology.organism_classification ,Kenaf ,chemistry.chemical_compound ,Coating ,chemistry ,Polymerization ,Electrical resistivity and conductivity ,Polyaniline ,Ultimate tensile strength ,Materials Chemistry ,engineering ,Composite material ,Electronic properties - Abstract
Conducting kenaf/polyaniline (KF/PANI) biofibers were successfully prepared via in situ oxidative polymerization. It was demonstrated, for the first time, the possibility of imparting new electronic properties on KF by coating with acid-doped PANI. The morphological analysis revealed three different PANI morphologies on the KF, depending on the type of acid doping. Enhanced interaction was achieved between the fiber-PANI surfaces, mainly from the π − π interactions. The newly developed conducting biofibers achieved enhancement in DC conductivity up to fivefold compared to the unmodified KF. Mechanical test on the conducting biofibers revealed no significant loss in the tensile properties.
- Published
- 2013
40. Simultaneous numerical optimization of the mechanical and electrical properties of polyaniline coated kenaf fiber using response surface methodology: nanostructured polyaniline on natural fiber
- Author
-
Mohd Yazid Yahya, Wan Aizan Wan Abdul Rahman, Noor Fadzliana Ahmad Sharif, and Saiful Izwan Abd Razak
- Subjects
Materials science ,biology ,Dopant ,Scanning electron microscope ,General Physics and Astronomy ,biology.organism_classification ,Kenaf ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Electrical resistivity and conductivity ,Polyaniline ,Ceramics and Composites ,Response surface methodology ,Fiber ,Composite material ,Natural fiber - Abstract
Response surface methodology was used to simultaneously optimize the electrical and mechanical properties of newly developed conducting biofibers made up of kenaf fiber/polyaniline (KF/PANI). The effect of process parameters such as PANI amount (1–10 wt.%), dopant concentration (5–25 N), and molar ratio of aniline/oxidant solutions (0.5–1.5) were studied using Design of Experiment. Both of the responses (electrical conductivity and unit break) obtained a quadratic model. The experimental values were in good agreement compared to the optimized process. The scanning electron microscope images of the optimized sample revealed uniform PANI component on the KF with nanofibrillar features.
- Published
- 2012
41. In situ surface modification of natural fiber by conducting polyaniline
- Author
-
Mohd Yazid Yahya, Saiful Izwan Abd Razak, Wan Aizan Wan Abdul Rahman, and Shahrir Hashim
- Subjects
Materials science ,General Physics and Astronomy ,engineering.material ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Polymerization ,Coating ,Electrical resistivity and conductivity ,Polyaniline ,Ceramics and Composites ,engineering ,Surface modification ,In situ polymerization ,Composite material ,Natural fiber ,Tensile testing - Abstract
Newly modified biofibers made up of kenaf fibers (KF) and conducting polyaniline (PANI) were successfully prepared via in situ polymerization. Several characterization methods were done to elucidate the interaction between the KF surfaces and the in situ polymerized PANI. The PANI coated KF (KF/PANI) achieved new electronic properties, without sacrificing its mechanical properties and natural fiber characteristic. Initial mercerization on the KF yielded better PANI coated fibers compared to the untreated KF. Fiber bundle tensile test on the untreated KF/PANI revealed a drop in the unit break of about 48% compared to the untreated neat KF. Meanwhile, the mercerized KF/PANI showed reduction of about 17% compared to the uncoated mercerized KF. The mercerized KF/PANI exhibits polaronic transitions, existence of favorable IR peaks and Raman scattering, enhanced DC conductivity, and better morphological characteristic as a result of the in situ PANI coating. Such electronically modified natural fibers could be ...
- Published
- 2012
42. Measurement and simple equation models of the specific heats of neat and glycerol-plasticized poly(vinyl alcohol)
- Author
-
Tiam Ting Tee, Wan Aizan Wan Abdul Rahman, Abdul Razak Rahmat, Soo Tueen Bee, Lee Tin Sin, and Chong Yu Low
- Subjects
Marketing ,Vinyl alcohol ,Materials science ,Polymers and Plastics ,Specific heat ,General Chemical Engineering ,Simple equation ,General Chemistry ,chemistry.chemical_compound ,Differential scanning calorimetry ,Chemical engineering ,chemistry ,Polymer chemistry ,Materials Chemistry ,Glycerol - Abstract
The specific heats (Csp) of neat and glycerol-plasticized poly(vinyl alcohol) (PVOH) were studied by differential scanning calorimetry at 330530 K. Glycerol-plasticized poly(vinyl alcohol) was prepared by a melt-blending method. The outcomes were modeled into mathematical functions. Incorporation of glycerol increased the specific heat of PVOH. Glycerol provided internal lubrication to the PVOH system, giving a smoother and lower-amplitude melting curve. As a result, glycerol-plasticized PVOH had a lower melting-temperature range than neat PVOH. However, higher energy was required to increase the temperature of glycerol-plasticized PVOH. The modeling functions showed a best fits regression range of 0.9670.999. Neat PVOH and glycerol-plasticized PVOH required 1166.05 J/g and 2113.09 J/g, respectively, to increase the temperature from 330 to 530 K. J. VINYL ADDIT. TECHNOL., 18:198203, 2012. (c) 2012 Society of Plastics Engineers
- Published
- 2012
43. Modified polydimethylsiloxane/polystyrene blended IPN pervaporation membrane for ethanol/water separation
- Author
-
Iqbal Ahmed, Wan Aizan Wan Abdul Rahman, Mohd Ghazali Mohd Nawawi, and Nasrul Fikry Che Pa
- Subjects
Chromatography ,Materials science ,Polymers and Plastics ,Polydimethylsiloxane ,technology, industry, and agriculture ,Ultrafiltration ,macromolecular substances ,General Chemistry ,Permeation ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Materials Chemistry ,medicine ,Polystyrene ,Pervaporation ,Interpenetrating polymer network ,Swelling ,medicine.symptom - Abstract
In this article a modified polydimethylsiloxane (PDMS) blended polystyrene (PS) interpenetrating polymer network (IPN) membranes supported by Teflon (polytetrafluoroethylene) ultrafiltration membrane were prepared for the separation of ethanol in water by pervaporation application. The relationship between the surface characteristics of the surface-modified PDMS membranes and their permselectivity for aqueous ethanol solutions by pervaporation are discussed. The IPN supported membranes were prepared by sequential IPN technique. The IPN supported membrane were tested for the separation performance on 10 wt % ethanol in water and were characterized by evaluating their mechanical properties, swelling behavior, density, and degree of crosslinking. The results indicated that separation performance, mechanical properties, density, and the percentage of swelling of IPN membranes were influenced by degree of crosslink density. Depending on the feed temperature, the supported membranes had separation factors between 2.03 and 6.00 and permeation rates between 81.66 and 144.03 g m-2 h-1. For the azeotropic water–ethanol mixture (10 wt % ethanol), the supported membrane had at 30°C a separation factor of 6.00 and a permeation rate of 85 g m-2 h-1. Compared to the PDMS supported membranes, the PDMS/PS IPN supported blend membrane ones had a higher selectivity but a somewhat lower permeability.
- Published
- 2011
44. Effect of Glycerol on Performance Rice Straw/Starch Based Polymer
- Author
-
Wan Aizan Wan Abdul Rahman and Muhamad Zaini Yunos
- Subjects
chemistry.chemical_classification ,Thermogravimetric analysis ,Multidisciplinary ,Materials science ,Absorption of water ,Thermoplastic ,Starch ,food and beverages ,chemistry.chemical_compound ,chemistry ,Ultimate tensile strength ,Glycerol ,Extrusion ,Composite material ,Tensile testing - Abstract
The effect of glycerol on the mechanical, thermal and water absorption properties of thermoplastic tapioca starch reinforced rice straw fiber grinded in the range below 100 µm was investigated. Compound formulation was done on twin screw extrusion and the extrudates were pelletized. The compounded samples were processed using compression moulding to form sheet at 150°C for tensile and thermal gravimetric. SEM studies were investigated on fracture surface of composites. Tensile test was done in accordance to ASTM D638. Thermal analysis was used to determine the degradation temperature of composite. Increasing the amount of glycerol increased the tensile strength of composite up to 30 phr of glycerol, however, increasing to 40 and 50 phr glycerol was decrease the strength but elongation at break of composites was increased with increasing glycerol content. Thermal Gravimetric Analysis (TGA) result showed that increased amount of glycerol content lead to decrease in degradation temperature of the composite and SEM micrograph showed that good dispersion and adhesion between rice straw fiber and starch.
- Published
- 2011
45. Mechanical and water absorption properties of poly(vinyl alcohol)/sago pith waste biocomposites
- Author
-
Toh Wen Yee, Lai Jau Choy, and Wan Aizan Wan Abdul Rahman
- Subjects
Vinyl alcohol ,Materials science ,Absorption of water ,Mechanical Engineering ,Plasticizer ,Compression molding ,Young's modulus ,chemistry.chemical_compound ,Cellulose fiber ,symbols.namesake ,chemistry ,Mechanics of Materials ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,symbols ,Cellulose ,Composite material - Abstract
A series of blends of sago pith waste (SPW) and poly(vinyl alcohol) (PVA) were prepared. Mechanical and water absorption properties of the composites have been investigated. In this study, variable amounts of plasticized SPW (pSPW) and PVA (pPVA) were processed in the presence of glycerol as plasticizers. Composites were compression molded and evaluated. The addition of pSPW reduced the tensile properties of the composites, lowering the elongation and increasing Young’s modulus. The reduction in mechanical strength with the addition of pSPW was a general phenomenon due to the poor interfacial adhesion between the pPVA and Pspw, which can be proved by the scanning electron microscope observations. The percentage of water absorbed of the pPVA/pSPW biocomposites was higher than either the pPVA or pSPW alone while pSPW showed better water resistance compared to pPVA because of the restricted mobility exerted by the cellulose fibers. The incorporation of SPW into PVA decreased both the mechanical and water absorption properties.
- Published
- 2011
46. Comparison of rice husk-filled polyethylene composite and natural wood under weathering effects
- Author
-
Lee Tin Sin, Abdul Razak Rahmat, Wan Aizan Wan Abdul Rahman, Naurah Mat Isa, Mohd Shahrul Nizam Salleh, and Munirah Mokhtar
- Subjects
Materials science ,biology ,Mechanical Engineering ,Composite number ,Izod impact strength test ,Weathering ,Polyethylene ,biology.organism_classification ,Husk ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Koompassia malaccensis ,Materials Chemistry ,Ceramics and Composites ,Composite material - Abstract
The weathering performance of rice husk-filled high-density polyethylene (RHPE) and natural wood was investigated in this study. The injection molded RHPE, in column end-cap (CECap) shapes, was exposed to both natural and accelerated weathering attacks. The durability of RHPE was compared to Kempas wood (Koompassia malaccensis) and neat polyethylene. Wood underwent the greatest losses in properties among the specimens. Four months of outdoor weathering turned the color of RHPE CECap into silvery grey. When the exposure time increased, the color of RHPE composite faded faster than neat polyethylene. The wood surface darkened and RHPE surface flaked off after being exposed to accelerated weathering conditions. Prolonged weathering exposure caused loss of impact strength of the RHPE composites. In general, RHPE is more resistible to weathering attacks as compared to Kempas wood.
- Published
- 2010
47. Thermal behaviour and interactions of cassava starch filled with glycerol plasticized polyvinyl alcohol blends
- Author
-
Lee Tin Sin, Adlina Abdul Samad, Wan Aizan Wan Abdul Rahman, and Abdul Razak Rahmat
- Subjects
Materials science ,Polymers and Plastics ,Starch ,Organic Chemistry ,Plasticizer ,food and beverages ,Polyvinyl alcohol ,Thermogravimetry ,chemistry.chemical_compound ,Differential scanning calorimetry ,Chemical engineering ,chemistry ,Phase (matter) ,otorhinolaryngologic diseases ,Materials Chemistry ,Organic chemistry ,Thermal stability ,Polymer blend - Abstract
Thermal behaviour and interactions of glycerol plasticized polyvinyl alcohol (PVOH)–cassava starch (CSS) blended films were analysed using thermogravimetry and differential scanning calorimetry methods. The outcomes showed that addition of glycerol has reduced the onset and end-point melting temperatures of the blended films. Samples with 30 and 40 wt.% of PVOH–glycerol blended with CSS exhibited experimental enthalpy of melting (ΔHm) lower than theoretical enthalpy of melting (ΔHmi). Meanwhile, the thermogravimetry degradation of the PVOH–glycerol–cassava starch can be divided into three phases, whereby phase 1 is the vaporization of volatiles, phase 2 is the rapid decomposition/dehydration and elimination of degradants and phase 3 is the formation of carbonaceous residues. These samples have thermogravimetry degradation activation energy (Ea) higher than their original components. For instance, 20 wt.% of PVOH–glycerol blended with CSS has a Ea which is 6.36 and 4.07 times higher than glycerol plasticized PVOH and CSS, respectively. Blending of PVOH–glycerol and CSS are favorable to produce biodegradable compounds resist to thermal attacks.
- Published
- 2010
48. Computational modeling and experimental infrared spectroscopy of hydrogen bonding interactions in polyvinyl alcohol–starch blends
- Author
-
Wan Aizan Wan Abdul Rahman, Abdul Razak Rahmat, Adlina Abdul Samad, and Lee Tin Sin
- Subjects
Polymers and Plastics ,Chemistry ,Austin Model 1 ,Hydrogen bond ,Starch ,Organic Chemistry ,Analytical chemistry ,Infrared spectroscopy ,Polyvinyl alcohol ,Hildebrand solubility parameter ,chemistry.chemical_compound ,Chemical engineering ,Molecular vibration ,Materials Chemistry ,Polymer blend - Abstract
This study aims to investigate the hydrogen bonding interactions in polyvinyl alcohol (PVOH)–starch blends. Semi-empirical AM1 (Austin Model 1) and PM3 (Parameterized Austin Model 3) methods were employed to model the blending. Binding energies, vibrational frequencies and solubility parameters results were used to analyze the compatibility and stability of the blends. Besides that, experimental infrared spectroscopy was also conducted to validate the modeling results. The computed negative binding energies justified the stability of the blending. On the other hand, the solubility parameters of PVOH and starch modeling complexes have been found close to each other. This confirms that PVOH and starch are compatible blends. In addition, vibrational frequency analysis of these molecular complexes has exhibited that the hydroxyl group shifts to lower wavenumbers due to formation of hydrogen bonds. Findings from the experimental infrared spectroscopy have shown agreement with computational vibrational frequency results. The wavenumbers of the specimens increase is dependent on the ratios of PVOH in the blends. Such increment indicates that PVOH and starch interact in a harmonize manner and the blending is compatible.
- Published
- 2010
49. Approaches to improve compatibility of starch filled polymer system: A review
- Author
-
Abdul Razak Rahmat, Lee Tin Sin, Wan Aizan Wan Abdul Rahman, and Abdirahman Ali Yussuf
- Subjects
chemistry.chemical_classification ,Materials science ,Polymer science ,Starch ,food and beverages ,Bioengineering ,Polymer architecture ,Polymer ,Polyethylene ,Polyvinyl alcohol ,System a ,Biomaterials ,chemistry.chemical_compound ,Low-density polyethylene ,chemistry ,Mechanics of Materials ,Compatibility (mechanics) ,Organic chemistry - Abstract
When hydrophilic starch is incorporated into synthetic polymers, the resulting products are weakened, especially blending with hydrophobic polymers. Many researchers have been undertaking various approaches to improve compatibility of starch and synthetic polymers. However, no ultimate and comprehensive approach can be determined. This paper aims to investigate and discuss the improvement approaches which have been recently developed by researchers. Also, the extents of improvement are summarized as well. In order to simplify this review, synthetic polymers are categorized into polar and non-polar types. Low density polyethylene was studied as non-polar type polymer, while polyvinyl alcohol was studied to represent as polar type polymer. Both types of synthetic polymers were blended with starches and their results were reported well by researchers. All findings are very informative and further encourage research for other starch filled polymer systems as well. In short, appropriate modifications to starch filled polymer system would induce polarity of the materials and subsequently create harmonious intermolecular interactions among blending components for better product properties.
- Published
- 2009
50. Influence of Polyaniline Coated Kenaf Fiber on Kenaf Paper Sheet
- Author
-
Wan Aizan Wan Abdul Rahman, Nadirul Hasraf Mat Nayan, Saiful Izwan Abd Razak, and Nur Syafiqah Abdullah Hisham
- Subjects
Paper sheet ,Materials science ,biology ,Scanning electron microscope ,Pulp (paper) ,engineering.material ,biology.organism_classification ,Kenaf ,chemistry.chemical_compound ,chemistry ,Electrical resistivity and conductivity ,lcsh:TA1-2040 ,Polyaniline ,engineering ,Composite material ,lcsh:Engineering (General). Civil engineering (General) ,Electrical conductor ,Natural fiber - Abstract
This paper reports the properties of newly developed electrically conductive natural fiber paper sheet made up of kenaf fiber (KF) incorporated with polyaniline coated kenaf fiber (KF-PANI). This study proposed on dispersion of conductive filler in different amount (wt %) into kenaf pulp for developing different electrical conductivity. The conductive sheet (KF/KF-PANI) revealed a percolation concentration at 25 wt% of KF-PANI. Its scanning electron micrograph showed good paper formation with no significant damages.
- Published
- 2015
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