Birefringence and Light-Scattering Studies of Concentrated Polymer Solutions in Strong Flows

强流动中浓聚合物溶液的双折射和光散射研究

• 批准号: 8719993
• 负责人: L. Gary Leal
• 金额: $ 5.83万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-15 至 1989-06-15
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8719993&HistoricalAwards=false
• 关键词: Birefringence; Light; Scattering; Studies; Concentrated

This research deals with an experimental and theoretical study of concentrated polymer solutions in strong flows. The objective is a better understanding of the changes in polymer conformation which occur as a consequence of the flow, and conversely, the modifications of the flow which occur because of the polymer. The proposed experimental measurements utilize a two-color birefringence system to provide real-time data on polymer conformation in transient conditions, and dynamic light scattering to obtain local, instantaneous data on the velocity gradient in the flow. From a fundamental point of view, the concern is with the relationship between molecular parameters, particularly the molecular weight and molecular-weight distribution, on polymer relaxation phenomena in the so-called "viscoelastic" regime of large deformation from the equilibrium state. In a more general sense, the research deals with the effects of various kinds if flow on polymer conformation, and with the implications for polymer processing, including the potential for manipulation of macroscopic properties of polymeric materials through flow-induced modifications of conformation.

本研究对强流中的聚合物浓溶液进行了实验和理论研究。其目的是更好地了解由于流动而发生的聚合物构象的变化，以及相反地，由于聚合物而发生的流动的改变。所提出的实验测量利用双色双折射系统来提供瞬变条件下聚合物构象的实时数据，并利用动态光散射来获得关于流动中速度梯度的局部瞬时数据。从根本上讲，我们关注的是分子参数之间的关系，特别是分子量和分子量分布之间的关系，这些参数对聚合物在从平衡态到大变形的所谓粘弹性区域中的松弛现象。在更广泛的意义上，这项研究涉及各种IF流动对聚合物构象的影响，以及对聚合物加工的影响，包括通过流动诱导的构象改变来操纵聚合物材料宏观性质的可能性。