Preparation and study the mechanical properties of HEC/PVA composites by sound waves

Abstract

The HEC/PVA composite membranes of hydroxyethyl cellulose and poly vinyl alcohol were prepared by casting method, the appropriate weight of HEC was variable (0.1, 0.15, 0.2, 0.25 and 0.3 gm) dissolved in (25ml) of distilled water under stirring and heat (70?C) for (30 min.) then add the PVA with different weights (0.2, 0.4 and 0.6 gm) for each  HEC weight. In order to evaluate the mechanical properties of HEC/ PVA composite the ultrasonic measurements were performed at the samples , these properties are ultrasonic velocity, compressibility, acoustic impedance and bulk modulus, were made at fixed frequency (f =15KHz), another acoustic mechanical properties were measured and calculated at a same time such as the ultrasonic wave amplitude before and after absorption by composite were measured using oscilloscope ,then we calculated absorption coefficient , transmittance and the reflected pressure ratio of the sound. It was found that there is significant relationship between ultrasonic velocity and material properties also results show that adding PVA affects on the density then the absorption of the ultrasonic waves inside the composites samples.

Keywords: hydroxylethel cellulose ;polyvinyle alcohol; mechanical properties; casting method.