Influence of gamma radiation on properties of common Brazilian wood species used in artwork

Abstract

Woods, as other materials, are susceptible to alterations in their internal structure because of physical, chemical or biological agents. Wood can be considered a natural composite with high strength capacity provided by cellulose and hemicellulose agglutinated by lignin, substances with very distinct structures. In several applications, the use of radiation can be interesting, once it turns wood more resistant to biological demand. The application of gamma radiation in work of arts and archeological artifacts preservation began in 1970, in France. By other side, no changes in wood properties were desirable. Gamma radiation from a cobalt-60 source usually is applied as a tool to the decontamination of insects and microorganisms, as well as to provide resins cure in impregnated wood. In this way, the aim of this paper is to evaluate gamma radiation effects on some physical, thermal and mechanical properties of Brazilian wood species used in carving, as Cedro-Rosa ( Cedrella fissilis) and Imbuia ( Ocotea porosa). Gamma radiation process considered different doses (25 kGy, 50 kGy and 100 kGy). Results showed that no gamma radiation influences were detected in the studied wood properties in the dose range applied This is a relevant conclusion that will improve safety on arts conservation around the world.