Engineering Research Equipment Grant: Purchase of a low Stress Rheometer

建议购买一种能够对聚合物溶液进行稳态、瞬态和动态流变测量的流变仪。该设备将支持液晶、聚电解质、新型聚合物表征、硝化纤维素和氢丙基木质素中的聚集现象以及用作弹性体的离子单体的研究。这些材料具有复杂的流变行为，包括剪切速率和时间相关的粘度和弹性。为了表征这些微观结构在未扰动状态下的特性，必须在非常低的应力水平下进行流变测量。这些材料如此低的粘度和存储和损耗模量，需要极其灵敏的扭矩传感器。用所建议的设备进行流变学测量有两个目的。首先，人们可以将聚合物的微观结构与特定的流变特性联系起来，为如何改变聚合物的分子结构以获得所需的特性提供指导。其次，可以确定获得所需性能的最佳加工条件。

It is proposed to purchase a rheometer capable of making steady, transient, and dynamic rheological measurements of polymer solutions. This equipment would support research in liquid crystals, polyelectrolytes, characterization of novel polymers, aggregation phenomena in nitrocellulose and hydrozpropyl lignins, and ionomers used as elastomers. These materials have complex rheological behavior including shear rate- and time-dependent viscosity and elasticity. In order to characterize these microstructures in their unpreturbed state, it is essential to make rheological measurements at very low stress levels. These materials such low viscosities and storage and loss moduli that extremely sensitive torque transducers are needed. Rheological measurements with the proposed equipment serve two purposes. First, one can relate a polymer's microstructure to specific rheological properties, providing guidance on how to alter the molecular structure of a polymer to obtain a desired property. Secondly, one can determine the optimum processing conditions for obtaining desired properties.