Resumen

TORO, M.E.; RINCON, A.  y  TORRES, C. Thermal degradation of pinus caribe wood treated with CCA salts . Rev. Téc. Ing. Univ. Zulia [online]. 2004, vol.27, n.1, pp.47-54. ISSN 0254-0770.

In this work a comparative study of the thermal degradation of Pinus caribaea var hondurensis (PCHT) sapwood, treated with chrome-copper-arsenic (CCA) salts as preservative, with retention levels of 4.4 and 12.6 Kg/m³, and without treatment (PCHST), is reported. The different PCH samples were analyzed by thermogravimetric analysis (TGA) and thermal volatilization analysis (TVA) techniques. In the PCH treated wood, the CCA salts increases the temperature threshold of the initiation reaction of weight loss. On degradation the polymeric matrix shows an interaction, which is observed as destabilization. This result suggests that in the treated PCH wood, radical species formed during decomposition may abstract hydrogen atoms leading to an increase in chain scission and consequently to a lower degradation temperature. Volatilization of short chain fragments, formed in this way, very likely compete with the depropagation reaction. The main degradation products formed in PCH treated and untreated, as evidenced by IR spectroscopy, were carbon dioxide and short chain fragments. In the treated PCH, the latter possibly contains a lower proportion of carbohydrates and higher ring substitute in the guaiacyl units of the lignin component. These derivatives may arise from interaction of CCA components with C=C groups in the aromatic ring of lignin in the wood. 

Palabras clave : Pinus caribe wood; CCA salts; thermal degradation.