This work reports the preparation and study of poly(vinyl chloride) (PVC) with medium and high molecular weight using a Living Radical Polymerization (LRP) method in aqueous systems. The synthesis of ultra thermal stable PVC that falls outside the typical values known for the PVC industry is presented and PVC thermal stability is evaluated using a standard industrial method. The results presented in this manuscript suggest that the single electron transfer-degenerative transfer mediated living radical polymerization (SET-DTLRP) mechanism is the main factor influencing the thermal stability, since the polymerization temperature has no detectable effect on this property. In contrast to the Free Radical Polymerization (FRP), where low temperatures lead to PVC with high thermal stability that corresponds to a high molecular weight polymer, the polymerization temperature in SET-DTLRP (range 21-42 degrees C) has no detectable effect on the thermal stability of PVC. The final molecular weight is defined by the [monomer](0)/[ininitiator](0) ratio (degree of polymerization). The PVC synthesis reported in this manuscript was carried out in a 150 L pilot reactor, which represents a reliable approach in terms of hydrodynamic conditions, when compared with those at the industrial scale. (C) 2011 Elsevier Ltd. All rights reserved.