S.M.-S. Abdel-hamid

Physico-mechanical properties of chemically treated polypropylene rice straw bio-composites

Rice straw is causing in many countries severe environmental problems in terms of black clouds caused by the incineration process. Hence, among other reasons, the incorporation of ground rice straw as a filler and reinforcement material for polymers is of advantageous. In this study, Egyptian rice straw was used to reinforce commercial polypropylene and laboratory prepared maleic anhydride-grafted PP with the fill grades between 5wt% and 30wt%. Rice straw PP composites show an improved Youngs modulus at increased fill grades, against a decrease in tensile strength. The addition of 1% maleic anhydride per I g of rice straw as a compatibilizing agent caused further amelioration of the fiber/matrix bonding leading to improved mechanical behavior, which was also assessed using scanning electron microscopy. Additional assessments were made via thermographic analysis and density measurements.

Removal of Cyanide from Liquid Waste by Electrochemical Oxidation in a New Cell Design Employing a Graphite Anode

Removal of CN− from liquid solutions was studied experimentally by an anodic oxidation technique under various operating conditions. A new cell configuration was used, the cell consists of four vertical graphite rod anodes distributed at 90° on the circular circumference at a distance of 3 cm from the wall and surrounded by two cylindrical stainless steel screen cathodes from the inner and the outer side. Parameters investigated are the initial concentration of cyanide ions, applied current density, initial pH of the electrolyte, and electrolyte conductivity. All parameters were investigated at an operating time of 3 h. The % removal increased upon increasing the applied current density, increasing the electrolyte conductivity, and decreasing the initial concentration of CN−. Increasing initial pH from 4 to 8 increased the % removal by a factor ranging from 55 to 73%, further increase of pH up to 12 slightly increased the % removal (3–8%). Application of the present electrochemical reactor in treating cyanide containing effluents from different industries was highlighted.

Characterization of Vinyl Ester/Jute Fiber Bio-Composites in the Presence of Multi-Walled Carbon Nanotubes

In this study, vinyl ester –Jute fiber biocomposites were prepared using vacuum-assisted resin infusion (VARI) process. Woven Jute fibers were used with mass fraction 0.68. Multi-walled carbon nanotubes (MWCNTs) are added to the resin with weight ratio 0.5: 99.5 to investigate the thermo-mechanical properties of bio-composites. Storage and loss modulus of vinyl ester bio-composites were investigated in the presence MWCNTs over a range of temperature (25 to 160 oC) to measure the capacity of bio-composite to store and dissipate energy. Damping properties of vinyl ester bio-composites were studied in terms of tan (d). Viscoelastic test using dynamic mechanical analysis (DMA) showed that the glass transition temperature increases with the addition of MWCNTs up to 112.4 oC. Addition of jute fiber reinforcements improves the storage modulus value of vinyl ester more than 65% at room temperature. Significant improvement in storage modulus was found in the presence of MWCNTs.