The greater the variation in Tg compared with the matrix alone, the greater the plasticizing effect with an addition of mobility. The Tg values are plotted in Figure . The addition of plasticizer leads to a very significant decrease in Tg, between 14 and 64 °C, for the different formulations. This result is the consequence of various associated phenomena which are linked to (i) the strong C-Cl dipole of PVC which interacts with the different dipoles carried by the plasticizers (ester and urethane functions) creating weak stabilizing interactions (limiting exudation) and forming a relatively structured network, and (ii) the pendant chains which themselves bring free volume and therefore mobility to the network formed.