Replacing 10 php DOP plasticizer by ESO has slightly increased tensile properties of PVC. A variety of media were used to study the leaching property of PVC and the results showed that the presence of ESO as a secondary plasticizer improved the leaching characteristic. There was slight difference in the hardness of the PVC samples with and without the ESO. In general, the PVC material became softer when DOP was partly replaced by ESO. The hardness of both samples became smaller after soaking in water, 30 wt.% acetic and 10 wt.% KOH solution and much bigger in other media. After immersion in n-hexane, the 60/0 sample blistered and became very hard, while the hardness of 50/10 sample increased only 12%. The morphology of fractured surface of the samples after soaking in n-hexane has clearly demonstrated this result. The replacing 10 php DOP by ESO has been also improved remarkably migration characteristic, thermal properties, and movement and volatilization in hot air. That means, ESO could be used as a secondary plasticizer/thermal stabilizer in PVC formulation.
