Rendimento, caracterização física e eficiência do óleo de Nim (Azadirachta indica A. Juss) e de mamona (Ricinus communis L.) na melhoria da resistência da madeira de sumaúma (Ceiba pentandra (L.) Gaert.) ao cupim xilófago Nasutitermes corniger (Motsch.).

Abstract

Yield, physical characterization and efficiency of neem (Azadirachta indica A. Juss) and castor oil (Ricinus communis L.) oil in improving the resistance of kapok wood (Ceiba pentandra (L.) Gaert.) to the xylophagous termite Nasutitermes corniger ( Motsch.). The research aimed to evaluate the yield, physical characteristics, efficiency of neem (Azadirachta indica) and castor (Ricinus communis) oils and the effect of aging on the resistance of kapok wood (Ceiba pentandra) to xylophagous termites. To determine the oil yield and the physical characteristics of the solutions, the oils from neem and castor beans were extracted with absolute ethyl alcohol and used in the preparation of the solutions. Castor bean had lower moisture content and oil yield than neem. The density and viscosity of neem oil were lower than those of castor oil. Wood samples with dimensions compatible with each termite resistance test were treated to achieve a nominal retention of 10 to 16 kg of solution/m³ of wood. Part of the treated samples was subjected to aging and termite action. Neem and castor oil contributed little to improving the resistance of kapok wood (Ceiba pentandra) to xylophagous termites. Among the solutions tested, pure castor oil was more efficient. The aging of the samples (volatilization and leaching) had little influence on the strength of the wood. Pure neem and castor oils and solutions prepared with them, even with some termite repellency effect, their effect is not lasting, indicating that they should not be used in the treatment of wood in order to improve its resistance to xylophagous termites.