The effects of water soluble extractives on the acoustic properties of reed (Arundo donax L.)

The storage modulus (E') and the loss tangent (tan delta) of reed (Arundo donax L.) used for woodwinds were measured at 20 degrees C and 60 % relative humidity and the effects of water soluble extractives on these properties were discussed. The extractives increased both the E' and tan delta of reed. There was a linear relationship between the tan delta change and the weight loss due to extraction. By using an uniaxial rheological model considering the anatomical structure of reed, the E' and tan delta of reed were described using the storage moduli, loss tangents, and volume fractions of bundle sheaths and parenchyma cells. It was suggested that the extractives in parenchyma cells increased the modulus of elasticity for parenchyma cells by 25 % and reduced the relaxation time of parenchyma cells by a factor of three. The main constituents of extractives were glucose, fructose and sucrose.