植物鞣质材料的超声研究

Ultrasonic studies on vegetable tannin materials

对柯子（MY）、山竹（MA）和无患子（SB）鞣质化合物进行超声研究。用普罗克特法（PR）和超声法（UL）提取这些鞣质材料。分别研究其在不同浓度和温度下的密度、速度、黏度、绝热压缩系数、声阻抗、吸收系数、黏性弛豫时间和自由程等性质。结果发现在20～80℃每次升温间隔5℃的情况下，不同材料有相似的行为。鞣质的超声速率随温度的升高而增加。鞣质黏度随浓度和温度的增加而减小。鞣质的绝热压缩系数（二元和三元混合物中分子相互作用的量度）随温度的升高而降低。随着温度的升高，鞣质的分子间自由程（即分子缔合的程度）增加。鞣质的吸收系数（结构依赖性）随温度的降低而降低。声阻抗（组件间的分子相互作用）随温度的升高而增加。所有上述超声参数的值随着浓度的增加而增加。最后得出结论，超声法是一种简单、无损的分析鞣质材料的强有力技术。

Ultrasonic studies were performed on myrobalan, m^ngustan and soap berry tannin compounds. These tannin materials were extracted using Proctor Method （PR） and Ultra Sound （US） methods. The properties of densi- ty, velocity, viscosity, adiabatic compressibility, acoustic impedance, absorption coefficient, viscous relaxation time and free length were calculated at different concentrations and temperatures using both PR ＆ US extraction methods and their results were found to be having similar behavior at temperatures between 20℃ and 80℃ in step of 5℃. Ultrasonic velocity of the tannins increases with increase in temperature. Viscosity of the tannins decreases with increase in concentration and temperature. Adiabatic compressibility （which is a measure of molecular interactions in binary and ternary mixtures） for tannins decreases with increase in temperature. Inter molecular free length （which is a measure of molecular association） of tannins increases with increase in temperature. Absorption coefficient （structure dependant） for tannins decreases with temperature. Acoustic impedance （which accesses molecular interaction between components） increases with temperature. All the above mentioned ultrasonic parameters show an increase in its values with increase in their concentrations. Finally, it was concluded from the study that the Ultrasonic method is a simple and non-destructive powerful technique in analyzing the tannin materials.