GOALI: Structural Studies of Orientational Development in Polymers using Real-Time Non-Invasive Spectroscopic Methods

小行星9812088 这个由特拉华州大学和杜邦公司共同资助的GOALI奖，由材料研究部和数学和物理科学理事会多学科活动办公室共同资助，重点是在实际加工过程中对聚合物进行非侵入性分析。 振动光谱具有作为非侵入性探针的潜力，其对化学、构象、晶体和形态结构以及分子取向敏感。 红外光谱和拉曼散射都将用于检查聚合物薄膜和纤维，因为这些光谱探针对主链和侧链取向的发展敏感，并且与X射线衍射不同，不需要结晶区域的相干堆叠来提供结构信息。 作为一种光谱技术，拉曼散射是非侵入性的，能够区分构象异构体，并且当利用偏振拉曼散射的定向性质时，可以提供关于链取向的信息。拉曼散射的另一个优点是易于取样。 由于它是一种散射技术，因此可以在纤维束以及单个长丝上获得光谱。 相反，如果对薄膜的研究感兴趣，则红外（IR）吸收光谱是选择，因为对于相同的正常模式，吸收截面比散射截面大5-6个数量级，并且平坦的膜几何形状理想地适合于IR研究。 因此，IR和拉曼研究将在“真实的-时间”域中进行，因为在变形和/或加热期间聚（对苯二甲酸乙二醇酯）（PET）、聚（对苯二甲酸丁二醇酯）（PBT）和聚（萘二甲酸乙二醇酯）（PEN）中的结构和取向发展。 聚合物材料的使用在我们今天的生活中非常广泛。 这些材料提供给最终用户的价值与各种性质直接相关，例如， 弹性，韧性和强度，它们所表现出来的。 红外光谱和拉曼散射是无损评价聚合物材料取向和有序发展的重要分析技术。 传统上，研究是在聚合物加工成其最终形式之前或之后进行的（例如，汽水瓶），但这并没有提供一个深入了解结构发展的演变，因为它发生。 这里概述的拟议方法将允许实时测量材料加工时的局部顺序和方向。 这些光谱技术的应用，聚合物将提供重要的信息，在加工过程中开发的结构/性能的关系，并将使我们能够设计新的制造协议，以优化聚合物的性能。 ***

9812088 Rabolt This GOALI award between the University of Delaware and DuPont, co-funded by the Division of Materials Research and the Office of Multidisciplinary Activities of the Directorate for Mathematical and Physical Sciences, is focused on non-invasive analysis of polymers during actual processing. Vibrational spectroscopy has the potential to act as a non-invasive probe which is sensitive to chemical, conformational, crystal and morphological structure as well as molecular orientation. Both infrared spectroscopy and Raman scattering will be utilized to examine polymeric films and fibers because these spectroscopic probes are sensitive to the development of backbone and side chain orientation and unlike x-ray diffraction do not require a coherent stacking of crystalline regions in order to provide structural information. As a spectroscopic technique, Raman scattering is non-invasive, capable of differentiating between conformers, and can provide information on chain orientation when the directional nature of polarized Raman scattering is utilized. An additional advantage of Raman scattering is the ease of sampling. Since it is a scattering technique, spectra can be obtained on fiber bundles as well as individual filaments. If instead, studies of thin films are of interest, then infrared (IR) absorption spectroscopy is the choice since the absorption cross section is 5-6 orders of magnitude greater than the scattering cross section for the same normal mode and the flat film geometry is ideally suited for IR studies. Hence both IR and Raman studies will be conducted in the "real- time" domain as structure and orientation develop in poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT) and poly(ethylene napthalate) (PEN) during deformation and/or heating. %%% The use of polymeric materials is extremely widespread in our lives today. The value that these materials provide to the end user is directly related to the various properties, e.g., elasticity, toughness, and strength, that they exhibit. Infrared spectroscopy and Raman scattering are important analytical techniques for the non-destructive evaluation of the development of orientation and order in polymeric materials. Traditionally studies are done either before or after a polymer is processed into its final form (e.g., soda bottle) but this fails to provide an insight into the evolution of structural development as it happens. The proposed approach outlined here will allow for the real-time measurement of local order and orientation as materials are processed. The application of these spectroscopic techniques to polymers will provide important information on structure/property relationships which develop during processing and will allow us to design new manufacturing protocols to optimize polymer performance. ***