Abstract
The results corresponding to the measurement of the yellowness index of some synthetic resins used in conservation-restoration processes are presented. The studied materials have been subjected to thermal aging processes (50ºC and 80ºC) and light-thermal aging (UV-55ºC), in order to establish their long-term behavior, as regards their yellowing. Data related to the viscosity of its solutions and elasticity of its films are also provided. The resins studied have been: Paraloid B-72, Paraloid B-67, Plexigum P-24, Gelvatol 40-20, Mowilith 30 and Synocril 9122X.