Hazizan Md Akil

Thermal Properties of Kenaf-Filled Chitosan Biocomposites

Kenaf filled chitosan biocomposites have been prepared via solution blending method. 0.1 M acetic acid was used as diluent. Five types of biocomposites with different compositions of kenaf fiber by weight designated as (CH, CH7, CH14, CH21, and CH28) were prepared. Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) were performed to study various thermal properties of the biocomposites. It was found that the biocomposites have undergone several decomposition stages over a range of temperatures as revealed by TGA thermograms, with CH exhibited highest mass loss as compared to other composites. From the DSC thermogram, incorporation of kenaf dust into chitosan has reduced the thermal stability of the chitosan film. The reduction is proportionate to the amount of kenaf dust added and was attributed to the formation of inter- and intrahydrogen bonding between amine groups of chitosan matrix and hydroxyl methyl groups of kenaf fiber.

Influence of a plasticizer on the mechanical properties of kenaf filled chitosan bio-composites

Glycerol (Gy) and di-hydroxyl stearic acid (DHSA) were selected for potential plasticizers of kenaf filled chitosan bio-composites (KCB). Plasticized KCB at various concentrations of plasticizers (0.2%, 0.4% and 0.6%) were obtained by mixing using high speed homogenizer (10,000 to 29,000 rpm) followed by simple casting. Soft and flexible film was obtained with Gy plasticizing system (GyPS) and hard and brittle film was produced with DHSA plasticizing system (DPS). GyPS films exhibit good elongation at break (EB). Films with DPS show good tensile strength (TS) and Youngs modulus (YM) properties.

Preparation and characterization of 1,2,4,5-benzenetetra carboxylic-chitosan

Abstract Chemically cross-linked chitosan (MC) containing 1,2,4,5- benzenetetracarboxylic acid (BCA) as the cross-linking agent was prepared to improve the metal ions absorption capacity of native chitosan (NC) and limit its biodegradability. The Fourier transform infra-red (FTIR) and proton neutron magnetic resonance (1H NMR) results showed that BCA was successfully linked onto N-position of NC. The crystalline nature of NC was reduced significantly after cross-linking as examined by X-ray diffraction (XRD) analysis. Therefore, the glass transition temperature (Tg) of MC was higher than NC as reported by differential scanning calorimetry (DSC). Moreover, thermogravimetric (TGA) analysis showed that, MC had better thermal stability than NC. Morphology changes on the surface of NC and MC were characterized by field emission scanning electron microscopy (FESEM) and showed that MC had more porous surface than NC. In pH medium of 3 to 6, MC had excellent Cu (II) ions absorption capacity with a maximum 16 % higher than NC.

Polyurethane foam with multi walled carbon nanotubes/magnesium hybrid filler

The purpose of this paper is to investigate the effect of multiwalled carbon nanotubes (MWCNTs)/magnesium (Mg) hybrid filler in polyurethane (PU) foams with different weight percentages (0.5 wt.% to 3.0 wt.%). The PU/MWCNTs/Mg foam composites were formed by reaction of based palm oil polyol (POP) with methylene diphenyl diisocyanate (MDI) with ratio 1:1.1 by weight. The foam properties were evaluated in density, morphology and compressive strength. The addition of 2.5 wt.% hybrid filler showed the higher density in 59.72u2005kg/m3 and thus contribute to the highest compressive strength at 1.76u2005MPa. The morphology show cell in closed structure and addition hybrid filler showed uneven structure.

Synthesis and Characterization of Novel Hybrid MWCNT-Muscovite Composite Filler

A novel hybrid carbon nanotube-muscovite (CNT-muscovite) compound was synthesized via chemical vapour deposition (CVD) by directly grown CNT on muscovite particles. The synthesis of CNT using nickel catalyst and muscovite as a substrate material is rarely found. Morphological analysis using scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the CNT was successfully grown on muscovite flaky particles. The CNT-muscovite compound can be potentially used as a new class of filler in polymer composites technology.

Influence of Al2O3 as Filler Loading on the Fracture Toughness of Light-Cured Dental Resin Composites

The purpose of the present study was to evaluate the effect of filler loading on the fracture toughness of light-cured dental resin composites (DRCs). The monomer Bis-GMA and TEGDMA (75/25 wt/wt) were mixed with treated micro-sized aluminum oxide (Al2O3) particles ranging from 40-60 wt% as filler. The composite samples were cured with LED for 80s. The bulk density (g/cm3) and apparent porosity (%) of the samples were determined according to the ASTM standard. The fracture toughness (KIC) values of the composites were determined using a single edge notched specimen in the three-point bending test. There was a significant difference in KIC of the composites with different loading of Al2O3 particles (p < 0.05). The highest amount of filler (60 wt%) reduced the KIC value to 1.5 MPa.m1/2. As a conclusion, the Al2O3 particles used as filler loading does have an effect on the mechanical properties of DRCs.