They have been reported in previous study [
X-ray diffractographs of the polymer were obtained with Philips X-ray Pw 1710
Scheme 1. Structures of monomers and polymers have been synthetized and characterized in previous work and are used in the present study.
diffract-meter, using Ni-filtered CuKα radiation. Please do not revise any of the current designations.
1) Formation of Polymer disc
The solid polymer was grinded by manual mortar. The polymer powder was then taken to QwikHandi-Press (used in IR instrument) under pressure of 5 ton to get a uniform pellet of polymer with a thickness 0.9 - 1.2 cm.
2) Density measurements
The densities of polymers were determined at room temperature using the standard displacement method. The polymer sample was hanged by a Teflon wire (0.01 mm in diameter) to one arm of sensitive balance. Water was used as immersion liquid. Densities were calculated according to the following equation;
ρ = ρ 0 ( W − W t ) / ( W − W t ) ( W 1 − W 1 t ) (1)
where ρ0 is the density of water (0.9999 kg∙m−3 at RT 25˚C), W and W1, are the weight of polymer pellet in air and water respectively, Wt and W1t are weight of suspended Teflon wire in air and water respectively.
3) Ultrasonic Velocity measurements
Ultrasonic waves travel through any solid material at a specific velocity related to the material characterization and its density. Here, we used the pulse technique which is widely used to generate ultrasonic measurements for solid and fluids. A pulse of sinusoidal voltage is applied to a piezoelectric transducer that is directly contacted with the samples under investigation. The electrical pulse converted to acoustical pulse that transmitted into the medium. The pulse propagates down the medium, and reflected to the opposite face. The time intervals between successive echoes can be measured and velocity of the wave is determined. Once, time intervals duration is obtained and the thickness of the samples determined the velocity of the ultrasonic wave of the sample can be calculated by Equation (2);
V = 2 d / Δ t (2)
where d is the thickness of the sample and Δt is the time intervals (31).
In general, the solids are subjected to three types of stressing condition; uniaxial stress, triaxial stress and pure shear. If a uniaxial stress is applied on a body, then elongation in the same direction will be produced. Young’s modulus (E); defined as the ratio of the linear stress to linear strain. Shear of rigidity (G); defined as the ratio of the shear stress to the shear strain. Bulk modulus (K); defined as the ratio of the hydrostatic stress to the volumetric strain. Micro-hard- ness (H); is the resistant of material to being penetrated and eroded by another material’s shear projection. The four constants held as Equations (3)-(7);
L = ρ V l 2 (3)
G = ρ V s 2 (4)
E = 2 ( 1 + υ ) G (5)
K = L − ( 4 / 3 ) G (6)
H = ( 1 − 2 υ ) E / 6 ( 1 + υ ) (7)
where ρ is the density of the material, L is the longitudinal elastic modulus, Vl and Vs are the longitudinal and transverse ultrasonic velocities and υ is Poisson’s ratio [
The dielectric constant (έ), parallel resistance (Rp) and parallel capacitance (Cp) were determined for specimens in the form of discs. They were prepared as discussed lately, the diameter 10 mm and thickness about 7 mm. The measurements have been carried out at room temperature and frequency rang 100 Hz - 1 MHz using HIOKI 3532-50 LCR Hi TESTER.
The morphology of the polymer were examined by Scanning Electron Microscopy (SEM) using a JSM-5400 LV instrument; images were recorded with a Pentax Z-50P Camera with Ilford film at an accelerating voltage of 15 KV.