Braidot A A, Deiber J A
INTEC (UNL-CONICET), Santa Fe, Argentina.
Biorheology. 1999;36(3):267-84.
The linear viscoelastic model proposed in this work considers the viscoelastic nature of maturing gelatin solutions through a relaxation modulus that depends on temperature and maturation. This modulus is defined in the conceptual contexts of the classical rubber elasticity theory and the rheometric gel theory. An analysis of the relationship between the equilibrium elastic modulus and the percolation variable around the gel point is also included yielding a percolation exponent close to 1.7 as expected from previous theoretical predictions. Additionally, a simple kinetic model is proposed to follow the microstructural changes obtained as a consequence of the generation of junction zones, the number of which vary with time during the dynamic rheometric tests used in this work. Thus, the storage and loss moduli are measured at different temperatures and frequencies, during the period of gelatin maturation. The theoretical aspects of the rheological model are presented emphasizing the quantitative changes of rheological parameters with the maturation.
本工作中提出的线性粘弹性模型通过依赖于温度和成熟度的松弛模量来考虑成熟明胶溶液的粘弹性本质。该模量在经典橡胶弹性理论和流变凝胶理论的概念背景下定义。还包括对平衡弹性模量与凝胶点附近渗流变量之间关系的分析，得出的渗流指数接近1.7，这与先前的理论预测一致。此外，提出了一个简单的动力学模型来跟踪由于连接区的产生而导致的微观结构变化，在本工作中使用的动态流变测试期间，连接区的数量随时间变化。因此，在明胶成熟期间，在不同温度和频率下测量储能模量和损耗模量。介绍了流变模型的理论方面，强调了流变参数随成熟度的定量变化。
