Vibrational property changes of spruce wood by impregnation with water-soluble extractives of pernambuco (Guilandina echinata Spreng.) II: Structural analysis of extractive components

Abstract

Heartwood of pernambuco (Guilandina echinata Spreng. syn Caesalpinia echinata Lam.), which has been used as material for violin bows, was extracted by soaking in water, and the obtained extractives were analyzed. The main components of the extractives were identified to be protosappanin B and brazilin. In particular, protosappanin B occupied about 40% of the pernambuco extractives. The loss tangent (tan δ) of spruce wood impregnated with protosappanin B decreased markedly, the same as that of specimens impregnated with extractives before being purified. It is expected that protosappanin B can make a contribution to the decrease in tan δ due to impregnation with extractives. © The Japan Wood Research Society 2000.