Enhancement of mechanical properties for reinforced Iraqi bentonite clay polyvinyl chloride composite using ultrasonic technique

Abstract

This research is depended an accurate style in preparing homogenous solution of PVC- Iraqi Bentonite clay composite adoption of careful balance mechanism in the selection of the ratio of solvent and mixing time according to the speed of mixing 450 rpm . Particle sizes selected for Bentonite clay is <75 & <150µm and the calcination process was performed at 300, 700, and 900^oC for 2hr. The Bentonite particles were mixed with known concentration of PVA solution at 80^oC for half an hour, then dried, milled, and sieved for particle sizes as mention above. Mixture of PVC solution with reinforced Bentonite clay is used to prepare the composite under study. Effect of mentioned parameters on mechanical properties of PVC were performed by ultrasonic technique using frequency of 30 KHz. Addition of reinforced Bentonite generally enhanced the mechanical properties of PVC. Evidently the composite prepared from reinforced powder <75µm is a good medium for transfer ultrasound waves particularly at calcination temperature 300^oC, that is mean it has a good stability against mechanical waves, so they can be used as a coated material for objects that we don’t want them to be detected by sonar, while in the case of particles <150?m is not. Failure to obtain the same result at temperatures higher than 300^oC and the granular size <150µm due to the presence strong intermolecular interaction that is responsible for reducing the elasticity of composite , in other words, leave it semi-brittle, i.e. not have good stability. Highest enhancement in the absorption coefficient appears at 900^oC with preference to the specimen of particles <150?m,and the composite becomes good absorber for ultrasound. Moreover the addition causing a reduction in compressibility, thus there is a small strain in the composite as a result of ultrasonic stress.

Keywords: PVC composite, Bentonite clay, Ultrasonic technique