Engineering and Technology Journal

Binary polymer blend was prepared by the mechanical mixing of epoxy resin (EP) with polycarbonate (PC) in different weight ratios of (0, 5, 10, 15 and 20%). Charpy impact test was carried out on these blends to determine the values of impact strength (I.S). It was found that the blend of the ratio (20wt. %) of PC has the highest (I.S) compared with other ratios. For this reason, this percentage of mixing was selected to fabricate the composite materials. Hand lay-up method was utilized to synthesize the (single and hybrid) laminate composites with fiber volume fraction (Ф=15%). Glass and Kevlar fibers were used to reinforce the epoxy and its polymer blend with different sequences of skin and core layers of the composite. The values of Young's modulus (E), impact characteristics (I.S, Gc, Kc) and hardness were determined for these composites. It is found that the values of (E) and hardness decrease while the values of material toughness (Gc) increase with increasing the blending ratio of the polymer blend. It can also be noticed that the composite reinforced with Kevlar fibers records the highest value of (Gc) compared with other composites.

In the present research the rheological properties of polymer melt composed of (polypropylene- polycarbonate ) unfilled_ filled with different amounts of Iraqi carbon black (2 – 7) wt% was studied. Single screw extruder was used for development of these blends . The rheological behaviour of these blends was investigated by using rotational concentric type rheometer .
The rheological properties shear rate( ( , apparent viscosity (a), dynamic viscosity(ή ), shear stress (τ) and angular frequency (ω),shearing flow at various temperatures ( 220 ˚C, 240˚C and 260 ˚C) were studied and found to be increase with increasing the amount of filler and decrease with increasing temperature. The flow curves were determined in the range of shear rate from about (10 to10 2 ) s-1. The activation energy was also measured, the values of activation energy varied from(11.939 to 20.892) KJ/Mole for different formation.

In this work a composite materials were prepared containing matrix of polymer blend (polypropylene 80% + polycarbonate 20%) reinforced by (carbon black) with different of weight fraction %. The specimen sheet, were obtained by hotcompression from extruded material, using single extruder operated at a temperature between (190-200)Co. The extrusion processes give homogeneous mixer through a regular selection of machine screw revolution per minute and temperature used in extrusion process. The weight fraction of the carbon blacks ranged from 0.0 up to 20 wt % with the polypropylene and polycarbonate blend. All samples related to, mechanical, thermal and electrical tests were prepared by single –extruder. By discharging a high voltage through the composite it was found that the resistivity of the composite decreased from (1.00E+09)-(1.00E+028). Carbon black–polypropylene and polycarbonate composites show significant differences from the neat blends measured in the frequency range. The study of physical test show that the thermal conductivity decreases with the increase of weight fraction
from (0.157-0.23).

The goal of this research was to study some Rheological and optical properties of
poly carbonate in (chloroform and toluene) with different concentrations to know the
physical behavior of this polymer in two solvents at room temperature.It was
determined that the value of polymer solution in these two solvents with different
concentrations and the optical absorption, average viscosity molecular weight
Effective molecular radius. The results have shown that the values of density, (shear,
relative, specific, reduced, original) viscosities, Effective molecular radius and
average viscosity molecular weight, increase with poly carbonate concentration in
two solvents.The results also showed that prepared concentrations density was
significantly influenced by the density of solvents used; this influence was not in the
same magnitude for the rest of measurements and calculations. This may be due to
the dynamic behavior of the polymer in a solvent.