Previous FTIR and DSC observations of potential complexes of PVC with the U derivatives thiourea and dimethylurea showed that no complexation and associated reductions in Tgs occurred . Consequently, in addition to the potential PVC-U complex, we only describe our observations of the potential PVC-Tetramethylurea (TMU) and PVC-Acetamide (AC) complexes. We attempted to determine whether U and/or its TMU derivative and related AC compound can potentially replace DEHP as PVC's main plasticizer, and if either can, at what concentrations do they most effectively lower the Tg of PVC?