A.R. Rozyanty

The Effect of Different Alkaline Treatment Condition on Flexural Properties of Kenaf Bast-Unsaturated Polyester Composite

The biocomposites were prepared by using kenaf bast fiber mat as reinforcing materials at different percentage. The kenaf bast fiber was treated with alkaline at different sodium hydroxide (NaOH) percentage. From the results obtained, surface morphology of the treated kenaf bast fiber shows less impurity than untreated kenaf bast fiber. As for composites prepared from alkaline treated kenaf bast fiber, it showed higher mechanical properties as compared to those prepared from untreated kenaf bast fiber. The percentage of kenaf fiber in composites also plays a crucial role in determining the composite properties.

Effect of Modification Time of Kenaf Bast Fiber with Maleic Anhydride on Tensile Properties of Kenaf-Glass Hybrid Fiber Unsaturated Polyester Composites

Natural fiber reinforced polymer composites are generally lower in mechanical performance compared to synthetic fiber reinforced polymer composites. However, this disadvantage can be improved via chemical modification of the natural fiber and hybridization with synthetic fiber. In this study, kenaf bast fiber was used as reinforcement in unsaturated polyester composites. It was subjected to chemical modification with maleic anhydride at various treatment time i.e. 60, 90 and 120 minutes prior to composites production. The untreated and MA treated kenaf bast fiber were hybridized with 10 weight percent of glass fiber to produce kenaf bast/glass fiber reinforced unsaturated polyester composites. The effect of treatment time on weight percent gain and functional group changes via infra-red spectra of kenaf bast fiber were investigated. The effect of treatment time on tensile properties of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites were also studied. It was revealed that the weight percent gain of kenaf bast fiber increased with the increasing of treatment time. The increasing of treatment time resulted in the enhancement of tensile strength and modulus of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites which were attributed to the presence of C=C bonds of maleic anhydride and has been proven through fourier transform infrared spectrum.

Study of Cassava Starch Filled with Different Loading of Kenaf Core Fiber

Cassava starch (CS) films filled with different loading of kenaf core fiber (KCF) were prepared and tested. Three testing were carried out; tensile test, water absorption test, and oil absorption test. The tensile test showed an increase in stiffness of the modulus as the loading of KCF increased. Additionally, the increase of KCF loading also increased the amount of water and oil absorbed by the films.

Extraction of silica content from the Cymbopogan citratus (lemon grass) and its performance as reinforcement for polymers

Silica is widely used as sources for adsorption materials, medical additives and fillers in composite and rubber industries. The manufacturing process of commercial silica use in various industries is very expensive and energy extensive. Therefore, agricultural waste material such as lemon grass is seen as a potential alternative silica sources for replacement of commercial silica which is currently available in the industry. In this research, a simple method based on the acid leaching treatment with hydrochloric acid (HCl) was developed to produce purified silica from lemon grass, followed by thermal combustion at 600°C. Acid leaching temperatures of 33, 50, 80 and 110°C were used. The silica content, shape and texture of the lemon grass ash was characterized using scanning electron microcopy -energy-dispersive X-ray (SEM-EDX) analysis. The SEM analysis indicated the presence of tubular-shaped porous aggregates, spherical and fibrous shapes of untreated and treated lemon grass at 33°C to 110 °C. The high...

Kenaf-glass fiber reinforced unsaturated polyester hybrid composites: Tensile properties

The use of natural fibers in composite is rising in recent years due their lightweight, non-abrasive, combustible, non-toxic, low cost and biodegradable properties. However, in comparison with synthetic fibers, the mechanical properties of natural fibers are lower. Therefore, the inclusion of synthetic fibers could improve the mechanical performance of natural fiber based composites. In this study, kenaf bast fiber and glass fiber at different weight percentage loading were used as reinforcement to produce hybrid composites. Unsaturated polyester (UP) resin was used as matrix and hand lay-up process was performed to apply the UP resin on the hybrid kenaf bast/glass fiber composite. Effect of different fiber loading on tensile strength, tensile modulus and elongation at break of the hybrid composite was studied. It has been found that the highest value of tensile strength and modulus was achieved at 10 wt.% kenaf/10 wt.% glass fiber loading. It was concluded that addition of glass fiber has improved the te...

Transverse and Longitudinal Flexural Properties of Untreated and Maleic Anhydride Treated Kenaf Bast Fiber Reinforced Unsaturated Polyester Composites

Kenaf bast fibers were prepared into two types as untreated and maleic anhydride (MA) treated. Unsaturated polyester (UPE) resin was used as matrix and applied onto the kenaf bast fibers using hand lay-up method. Transverse and longitudinal flexural properties of unidirectional long kenaf bast fiber reinforced unsaturated polyester composites were performed and the effect of fiber modification and loading were studied. It is found that the transverse flexural strength of both types of composites decreases with the increasing of kenaf loading. Contrary, longitudinal flexural strength of both composites increases with the increasing of kenaf loading. Improved transverse and longitudinal flexural properties are shown by MA treatment of kenaf bast fiber. The interactions between fiber and matrix of fractured flexural surface were also observed by scanning electron microscope (SEM).

Effect of Montmorillonite Modification on Ultra Violet Radiation Cured Nanocomposite Filled with Glycidyl Methacrylate Modified Kenaf

In this study nanocomposite cured by ultra violet radiation, were produced using modified montmorillonite (MMT) as reinforcing agent, chemically modified kenaf bast fiber as filler and unsaturated polyester as the matrix. Kenaf bast fiber was chemically modified with glycidyl methacrylate (GMA) whilst MMT were modified with cetyl trimethyl ammonium bromide (CTAB) and glycidyl methacrylate (GMA). Fixed 12 percent of GMA modified kenaf bast fiber with different percentage (i.e., 1, 3 and 5) of unmodified and modified MMT loading was used to produce the composite. The performed of GMA reaction with hydroxyl group of cellulose in kenaf bast fiber was evaluated using Fourier Transform infrared (FTIR) spectroscopy. GMA-MMT filled composite showed higher mechanical properties than MMT and CTAB-MMT filled composite. However, the increase of MMT, CTAB-MMT and GMA- MMT loading resulted in the reduction of mechanical properties. Scanning electron microscopy (SEM) analysis showed the evidence of compatibility enhancement between MMT and kenaf bast fiber with unsaturated polyester matrix.

Crystallinity, Tapping and Bulk Density of Microcrystalline Cellulose (MCC) Isolated from Rice Husk (RH)

The isolation of microcryostalline cellulose (MCC) from rice husk (RH) via acid hydrolysis process has been successfully prepared by using different molarity of nitric acid (HNO3) and hydrochloric acids (HCl). The properties of MCC obtained such as tapping and bulk densities, thermal stability and percentage crystallinity were studied. Tapping and bulk densities shown comparable results regardless of different acid used that reflecting the potential of MCC as reinforcement filler in composite fabrication. The usage of 2M HNO3 gives highest percentage crystallinity (69%) in comparison with 2M HCl (49%). The result indicates the stability of MCC-RH obtained using HNO3 has great potential to replace strong acid in acid hydrolysis process.

Kenaf-Unsaturated Polyester Composite: The Effect of Different Retting Process of Kenaf Bast Fiber on the Mechanical Properties

Kenaf bast fiber reinforced unsaturated polyester composite was produced using kenaf bast fiber based on different retting process. There are two different retting method involved which are water and mechanical retting process. The composites were prepared by using hand lay-up method with different fiber loading (weight %) of 10, 15 and 20%. The mechanical test involved was tensile test and scanning electron microscope (SEM) was employed to investigate the fiber-matrix adhesion and fiber breakage. The result showed that the tensile properties of the composite increased as the fiber loading increased. Besides, the water-retted kenaf –UPE composites exhibited the highest mechanical properties as compared to mechanical-retted kenaf –UPE composites. While, the morphology analysis using SEM showed that water retted kenaf-UPE composite show better fiber distribution and better interfacial adhesion compared to mechanical retted kenaf-UPE composite.

Influence of Montmorillonite Treated with Cetyl Trimethyl Ammonium Bromide Addition in Epoxy-Kenaf Composites

The use of natural fiber as reinforcement in polymer composites has gained importance recently due to environmental concern and its abundance availability from agricultural crops and wood industry [1]. Many advantages offered by natural fibers over synthetic fibers include low density, greater deformability, low cost per unit volume, recyclability and biodegradability [2-3]. In addition, the mechanical properties of natural fibers such as flax, hemp, jute, sisal and kenaf are comparable with glass fiber in respect of strength and modulus [4]. Hence, many studies have been carried out to replace the synthetic fiber for composite preparation.