A. I. Mustafa

Comparative Studies of Mechanical and Interfacial Properties Between Jute and E-glass Fiber-reinforced Polypropylene Composites

Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m2, respectively. Then E-glass fiber (woven)-reinforced polypropylene-based composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.

Trace element concentrations in ten species of freshwater fish of Bangladesh

Abstract The edible portions of whole fish excluding viscera and bone of 10 species of small indigenous freshwater fish of Bangladesh, are analysed for sodium, potassium, calcium, magnesium, iron, manganese, nickel, copper, zinc, strontium and rubidium by atomic absorption spectrophotometer (AAS). Analytical quality is calculated by analysis of standard reference material MA-A-2(TM), fish flesh homogenate and MA-B-3(TM), fish tissue (lyophilised) prepared by the International Laboratory of Marine Radioactivity of the International Atomic Energy Agency, Monaco. Dietary implications of the results are discussed. It is observed that four species of fish contain a higher amount of lead than the limit set by the Australian National Health and Medical Research Council Standards (ANHMRC). The concentrations of lead and cadmium in the edible portions of other fish comply with the international standards for human consumption.

Trace metals in tropical marine fish from the Bay of Bengal

Concentrations of potassium, calcium, magnesium, manganese, iron, nickel, copper, zinc, lead, cadmium, strontium and rubidium were determined in the flesh of six marine fish species from the Bay of Bengal. Analytical quality was determined by analysis of standard reference material MA-A-2 (TM), Fish Flesh Homogenate, from IAEA (International Atomic Energy Agency). In most cases the results are similar to data published on fish from other marine environments.

Lead and cadmium contents in ten species of tropical marine fish from the Bay of Bengal

Abstract The lead and cadmium contents in ten different commonly consumed marine fishes collected from the Bay of Bengal were determined by atomic absorption spectrometry (AAS). The lead and cadmium contents in the edible fish flesh tissues, expressed in dry weight, varied from 0.58 μg g −1 ( Polynemus indicus , Lakhua and Leander styliferus Gura chingri) to 4.03 μg g −1 ( Racouda russelliana , Fatra, phatra) with an average value of 1.78 μg g −1 lead and 0.04 μg g −1 ( Sconberomorus guttatum , Maitya) to 0.13 μg g −1 ( Pangasius pangasius , Pangas) with an average of 0.08 μg g −1 cadmium, respectively in ten species of marine fishes. Analytical quality was determined by analysis of standard reference material MA-A-2(TM), Fish Flesh Homogenate, from IAEA (International Atomic Energy Agency). The results of this study positively indicate that the marine fishes from the Bay of Bengal have concentrations well below the permissible levels for these toxic elements.

Jute Reinforced Polypropylene Composite: Effect of Surface Pretreatment by Photocuring with Acrylic Monomers

Jute fiber (hessian cloth) reinforced polypropylene (PP) composites were prepared by compression molding. The composite fabrication temperature, pressure and time were 190°C, 4 tons and 5 min, respectively. The jute content, in the composites was studied over mechanical properties and it was observed that the highest TS (70 MPa), BS (75 MPa) and bending-E-modulus (2.35 GPa) were produced by 60% jute content, but Youngs modulus was found to be the highest (1.95 GPa) at 38% jute content. To further improve the mechanical properties and interfacial adhesion behavior between jute and polypropylene, hessian cloth was pretreated with acrylic monomers, e.g., 1,4-butanediol diacrylate (BDDA), ethyl hexyl acrylate (EHA) and trypropylene glycol diacrylate (TPGDA) at different concentrations using 2% photoinitiator (Darocur-1116) under UV radiation of various intensities. Among all the monomers BDDA showed the best performance. The highest TS (90 MPa), BS (95 MPa), Youngs modulus (2.2 GPa) and bending-E-modulus (3.2 GPa) of the composite were obtained when hessian cloth was cured by soaking it for 10 min in a solution containing 3% BDDA, 2% photoinitiator in methanol, followed by exposure to six passes of UV radiation. Under this condition polymer loading (PL) of photocured hessian cloth was 14%.

Study on Mechanical Properties of Photocured Films of Chitosan/PVA and PEO/PVA Blend with Acrylic Monomers

Abstract Natural polymer chitosan acts as a bioblending material, which was obtained from dried prawn shell waste through the preparation of chitin and was characterized. Bioblend films of polyvinyl alcohol (PVA)/chitosan and PVA/polyethylene oxide (PEO) were prepared. Mechanical properties like tensile strength (TS), elongation at break (Eb) of chitosan film were studied. Five formulations were developed with 2‐ethyl 2‐hydroxy methyl 1,3‐propandiol tri‐methacrylate (EHMPTMA), a tri‐functional acrylic monomer and 2‐ethylhexyl acrylate (EHA), a mono‐functional acrylic monomer in the presence of photoinitiator Darocur‐1664 (2%). The films were soaked in those monomer formulations in dissimilar soaking times and irradiated under UV‐radiation at different radiation intensities for the improvement of the properties of chitosan film. The cured films were then subjected to various characterization tests like TS, Eb, polymer loading (PL), water uptake, gel content etc. The formulation, containing 25% EHMPTMA and 73% EHA showed the best performance at 10th UV passes of UV radiation for 4 min soaking time. The bioblend film PVA/chitosan performed better physico‐mechanical properties rather than PVA/PEO.

Trace element concentrations in tropical marine fish from the Bay of Bengal

Abstract A survey of metal levels present in ten different species of important commercial fish of the Bay of Bengal is reported. The concentrations of sodium, potassium, calcium, magnesium, iron, manganese, nickel, copper, zinc, strontium and rubidium were measured on dry weight basis in the fish flesh of all species by atomic absorption spectrometry (AAS). Analytical quality was determined by analysis of standard reference material MA-A-3(TM), fish flesh homogenate and MA-B-3(TM), fish tissue lyophilised prepared by the International Laboratory of Marine Radioactivity of the International Atomic Energy Agency, Monaco. In most cases the results are similar to data published on fish from other marine environment. Concentrations of cadmium, lead, copper and zinc in all these species are below the standard of the Australian National Health and Medical Research Council (ANHMRC) for these elements in foodstuffs. The health risks associated with the presence of toxic metals in these species are discussed.

Determination of arsenic, chromium, mercury, selenium and zinc in tropical marine fish by neutron activation

Determination of arsenic, chromium, mercury, selenium and zinc in several commonly consumed tropical marine fishes have been carried out by neutron activation followed by radiochemical separation to remove the interfering activities of sodium, potassium, bromine, and phosphorus, etc., in order to establish the baseline data and to measure the levels of contamination, if any. The results of this study positively indicate that the marine fishes of Bangladesh have concentrations much below the permissible levels for these toxic elements. A radiochemical scheme for the separation of seven trace elements in biological material is also presented in this paper.

Effect of Gamma Radiation on the Physico- and Thermo-Mechanical Properties of Gelatin-Based Films Using 2-Hydroxyethyl Methacrylate (HEMA)

Gelatin films were prepared from gelatin granules in aqueous medium by casting. Tensile strength, tensile modulus, elongation at break and the glass point of the gelatin films were found to be 27 MPa, 100 MPa, 4% and 51.7°C, respectively. After irradiated with gamma radiation tensile properties were increased due to denser network structure. Gelatin films were soaked in five different formulations containing 2-hydroxyethyl methacrylate (HEMA) (10–50%, by wt), methanol and photoinitiator and then irradiated under gamma radiation. Again, a series of gelatin solutions was prepared by blending varying percentages (10–50% by wt) of HEMA and then films were prepared and irradiated under gamma radiation. It was found that tensile and thermal properties of gelatin films improved significantly.

Impregnation mode in wood plastic composite

Abstract Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of thcomposite of such an extent that there is virtually very little difference between vacuum impregnation and normal impregnation. Considering the available data it is suggested that the impregnation under normal condition is preferable beacuse different substrates of various sizes and shapes can be suitably impregnated under normal condition while vacuum impregnation has several limitations in this respect.