A STUDYOF THE EFFECT OF TYPE AND CONCENTRATION OF PLASTICISER ON THE DRY BLENDING, FUSION BEHAVIOUR, EXTRUDABILITY AND MECHANICAL PROPERTIES OF POLY VINYL CHLORIDE

Abstract

Attached

Plasticised PVC dry blends containing three different placstisers at three different level were prepared and torque temperature curves for dry blending characteristic and fusion behavior were obtained for each using Barbender planetary mixer and torque rheometer. Each sample was extruded at three different screw speeds to study the processability. Tensile tests were conducted on three extruded samples. The activity of the plasticisers was governed by their molecular weight and polarity. Efficiency of the plasticiser can be measured how fast plasticiser absorption take place during dry blending. Low molecular weight plasticisers generally are absorbed faster. Fusion is taken to imply the extent to which individual powder grains have fused together to from a continuous matrix. Fusion level also depended on plasticiser type. In general more compatible plasticisers enhanced fusion. The torque at fusion peak increased with PVC plasticiser compatibility, because fusion occurred at lower temperatures, where melt viscosity was higher. The type and concentration of plasticisers have significant effect on mechanical properties. The different plasticiser appeared to behave in a similar manner in reducing mechanical properties with increasing concentration. Mechanical properties increased with PVC plasticiser compatibility.