Adly Abdalla Hanna

Ammonium polyphosphate was prepared and used as flame retardant materials for polypropylene nanocomposites. Then, kaolin was incorporated with ammonium polyphosphate nanoparticles as synergistic flame retardant system for polypropylene. This is in addition to modification of kaolin with sulfuric acid then incorporated with polyphosphate nanoparticles as good flame retardant materials for polyproplylene. Flammability properties of polymer developed polymer nanocomposites were improved achieving 26.4 and 10.2 % reduction in peak heat release rate (PHRR) compared to virgin polymer and polymer composite with ammonium polyphosphate nanoparticles alone. The synergistic effect of modified kaolin and nanoparticles was evaluated. The dispersion of ammonium polyphosphate and kaolin in polymer matrix were studied using microscopic techniques.

In a previous work [1], we prepared О±-Zr(HPO4)2.2H2O (ZrP) by direct precipitation, reflux, and by sol-gel method. The results of characterization indicated that the properties of the resultant ZrP samples depended on the method and conditions of preparation as well as on the nature of precursor used. As an important factor governing the use of such layered phosphates, various modifications were done to enlarge the interlayer spacing of α-ZrP (7.6 А) to be suitable for exchange of large cations. This work aims to modify the interlayer spacing of α-ZrP prepared from zirconium acetylacetonate complex and phosphoric acid. Two routes were used to achieve this goal; the first is by intercalation of acid α-ZrP with n-butyl amine in its vapor-saturated atmosphere. The second route is by performing ion-exchange of the α-ZrP protons by different cations.

The organic matter was removed from the crude wet‐process phosphoric acid, produced by treating the Egyptian phosphate ore with sulphuric acid, using fine powder charcoal. The optimum charcoal/acid weight ratio, the effect of the acid concentration and the temperature on the efficiency of removal were studied.It is found that the percentage of the organic matter content decreases from 2·172 × 10⁻², for the crude phosphoric acid, to 0.108 × 10⁻² after treatment of 70 g acid with 600 mg fine powder charcoal. When the charcoal/crude acid weight ratio reaches 1%, the crude acid becomes free from the organic matter and its colour turns from dark‐brown into pale‐green. This green colour is due to the presence of Fe²⁺ ions.Also, it is found that as the acid concentration decreases, the efficiency of the charcoal in removing organic matter increases. This may be due to the decrease of the acid viscosity, by dilution, which enables the charcoal particles to spread and penetrate more easily through the medium.The results of the effect of temperature show that the efficiency of charcoal in removing organic matter increases as the temperature is raised. This increase is also attributed to an increase in the charcoal apparent activity due to the decrease in the acid viscosity with temperature, leading to less possibility of scaling and more net surface area available for adsorption.