Efecto de los pigmentos en la estabilidad atmosférica de dos formulaciones industriales de plasticos de PVC para aislantes de cables eléctricos

Abstract

The atmospheric ageing oftwo industrial formulations of PVC plas­tic for insulating electric cable has been studied for five years in the Cuban tropi­cal humid conditions. The PVC isolator was employed in the Cuban industry for years. The natural and pigmented samples (green, red and black) were exposed at the three different test stations (country, marine and industrial). At the country and marine stations the sample was exposed to outdoors and sheltered condi­tions. At the industrial station the sample was exposed outdoors only. The varia­tion of the properties of material during ageing was studied by visual control, physical-mechanical, dielectrical and biological tests. The sample with black pig­ment, had a better behaviour during a longer period outdoors. The samples con­taining green and red pigments presented. a slight superior behaviour than the natural samples. The samples containing black pigment, after two years expo­sure, in marine conditions do not have the same protection as in industrial and country enviromental conditions. By microbiological test was determined that the microorganisms do not change the physical-mechanical, dielectrical proper­ties, in the sheltered conditions for five years. The climatic actions in the differ­ent test stations do not always behave in the same way for the same material.