The mechanical, thermal, morphological, dynamical mechanical and Electrical properties of polymeric insulators are tested and reported. Low density polyethylene (LDPE), ethylene-propylene-diene monomer (EPDM) and blends of LDPE/EPDM are known polymers for use as low, medium and high voltage insulators. Several formulations containing EPDM and LDPE were prepared. EPDM was blended with LDPE in different weight ratios of LDPE/EPDM (100/0, 80/20, 60/40, 50/50, 40/60, 20/80, 0/100). The change in Haake-viscosity mixing torque with time for different blend compositions was obtained. The torque at any time is dependent on the blend composition. For EPDM the observed torque is directly influenced by its cross-linking density. However, for LDPE or blends of high percentage of LDPE the influence of cross-linking density on torque is relatively low. The mechanical properties of cross-linked EPDM are weaker than LDPE. Therefore changing the cross-link density of EPDM will not affect the blend properties significantly especially at high LDPE content. A drop shape analysis system G l0 (Kruss-USA) was used for hydrophobicity studies. Studies illustrate that in LDPE/EPDM blends, tensile strength of the blends are higher than either polymer component alone. But the synergism effect in LDPE/EPDM compound is stronger than HDPE/EPDM. Also the blends of LDPE/EPDM show good breakdown voltage strength and heat resistance comparing to LDPE. The result of mechanical measurement shows that mechanical properties such as tensile strength, modulus and elongation-at-break of blends can be enhanced with increase in LDPE in the formulation. Also tests were conducted to study various properties (mechanical, surface, Electrical) under accelerated ageing condition. Because the life time of these compounds are generally too long to wait for a verdict on their behaviour in use. The ageing results show that mechanical properties follow the same trend as pre-ageing stage.

Cross linking of high density polyethylene (HDPE) was performed via high energy electron beam (EB) irradiation. HDPE was also cross linked with dicumyl peroxide (DCP). The gel content of samples was determined by solvent extraction. The degree of cross linking was evaluated by hot set apparatus; also. In order to clarify the effect of the nature of cross linking, correlation of Electrical properties such as volume resistivity, dielectric constant, and dielectric strength with the type of cross linking system was derive. It was found that, at identifical amount of gel content, Electrical properties of samples prepared by two kinds of cross linking methods, differed significantly.

To fabricate ultra-fine grain structures containing high strength, accumulative roll bonding is a kind of severe plastic deformation (SPD). In the present study, magnetic Al/ Fe2O3 composites reinforced with 0, 2. 5% and 5Wt. % of Fe2O3 particles have been manufactured via ARB. A uniform distribution of Iron oxide particles was achieved after the 8th cycles of ARB. Mechanical properties include (hardness, elongation, toughness) and also, magnetic and Electrical properties such as magnetic saturation, magnetic permeability and magnetic residuals were studied. The presence of Fe2O3 particles improved the mechanical, Electrical and magnetic properties of this kind of laminated composites. Vibrating sample magnetometer was utilized to study the magnetic properties of samples vs No. of steps.

Spectroscopic measurements in the range of 10 kHz to MHz at different temperatures are reported for Au/CIMgPc/Au thin film sandwich devices. The ac conductivity is found to vary with the angular frequency ω as ωn where the index n≈ 1at high frequencies indicating the predominance of a hopping conduction mechanism in this material at low temperatures and high excitation frequencies. The variation of activation energy is studied as a function of temperature and frequency. The capacitance data are analysed within the framework of the Goswami model [10].      

The Electrical properties of rock types or channel structures have been the object of intense studies for many years. The main aim of the present work is to show the frequency response of Electrical properties of some Granite samples concerning chemical, minor and major composition. This may be used as a fingerprint for the characterization of some Granite rocks. Electrical measurements on Granite samples (surface, Aswan, Egypt) were measured (100 Hz up to 107 Hz). Differences in samples due to changes in texture lead to different changes in Electrical properties. The changes at conductivity and dielectric constant are reflections from the texture within grains. Conductivity and dielectric constant values extend from ~10-8 to 10-4 (S/m) and 24 to 3. 5, respectively. With frequency increase, conductivity increases, and dielectric constant decreases (10 kHz), and then it settles down. Differences in Electrical properties between samples are small as a direct result of the homogeneity and texture of most samples. There is a high dispersion of dielectric constant for relatively low-frequency values (<10 kHz) and no dispersion at relatively high frequencies. In conclusion, the dielectric constant decreases due to the shrinkage of energy levels for electrons and the increase of hopping particles between different particles.