Paper Title
PVC Compounding: Preparation, Physical and Mechanical Properties

Abstract
Compounding of PVC representsan important class of engineering materials that havebeen intensively developed in recent decades. Theincorporation of different additives such as fillers, plasticizers, and stabilizers, into thermoplastics has beenwidely practiced in industry to extend them and toimprove their properties. Among these improvedproperties are mechanical characteristics, dimensionstability, permeability, processability, thermal stabilityand flame-retardant enhancements, as well as costreduction with respect to the bulk polymers. In the present study, compounding of Polyvinylchloride (PVC) with some additives is studied for the enhancement of physical and mechanical properties. Composites of poly(vinyl chloride) (PVC) is blended with different fillers, stabilizers , plasticizers and lubricant such as: calcium carbonate as a filler and stearic acid as a lubricant, tribasic lead sulfate as a stabilizer and Di-octyl phthalate (DOP) as a plasticizer, and the effect of compounding on the physical and mechanical properties of polyvinylchloride (PVC) is studied.The experimental work is conducted in a batch mixer at a temperature of 120º C for half an hour with continuous stirring for both rigid and soft PVC. In case of rigid PVC, the filler content ranged from 10- 20% by weight of sample, tribasic lead sulfate (2.2 wt%) and lubricant (stearic acid 0.5 wt%) and no plasticizer is added in the sample . In case of soft PVC, no filler is added, plasticizer ranged 60- 90%,by weight of sample, tribasic lead sulfate stabilizer (3 wt%) and lubricant (stearic acid 0.5 wt%). In case of rigid PVC, experimental results show that tensile stress increased with increasing filler content and reached maximum value of (531 kg/cm2) at12 % weight of CaCO3 filler. Yield stress increased with increasing filler content and reached maximum value of (521 kg/cm2) at 12 % weight of CaCO3 filler. On the other hand, the Izod Impact decreases with increasing filler content. % Elongation at break increased with increasing filler content and reached maximumvalue of (200 %) at 12 % weight of CaCO3 filler.Relative density of rigid PVC is directly proportional with % weight of filler. In case of soft PVC, experimental results show that tensile stress is directly proportional with plasticizer content and the optimum % plasticizer is 70 %. Relative density of soft PVC is directly proportional with % weight of plasticizer and the optimum % plasticizer is 70 %.% Elongation at break increased with increasing plasticizer content and reached maximum value of (380 %) at 70 % weight of plasticizer and then decreased. Hardness (shore A) is directly proportional with plasticizer content. Key words - PVC, compounding, fillers, plasticizers,stabilizers,lubricant, physical properties, mechanical properties.