Collaborative Research: Connecting the Wetting and Rheological Behaviors of Compatibilized Polymer Droplets in Immiscible Polymer Melts

合作研究：将不混溶聚合物熔体中增容聚合物液滴的润湿和流变行为联系起来

• 批准号: 0706432
• 负责人: Timothy Long
• 金额: $ 11.1万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0706432&HistoricalAwards=false
• 关键词: Collaborative; Research; Connecting; Wetting; Rheological

TECHNICAL SUMMARY:The objective of the research is to elucidate and quantify how the wetting of diblock copolymers governs the dispersion of polymer droplets in immiscible polymer blends. Specifically, monodisperse polydimethylsiloxane-polyisoprene (PDMS-b-PIP) diblock copolymers will be synthesized, and these components will be added to immiscible blends of PDMS and PIP to formulate of well-defined model systems of PDMS/PMDS-b-PIP/PIP. The advantage of using these systems is that the coalescence of the droplets, which depends on the amount of copolymer at the droplet interface, can be studied in either the PDMS or PIP matrices, which are both melts at room temperature. The use of these components will help to establish whether wetting phase diagrams, which depend on the chain lengths of the block copolymers and matrix polymers, can be used to predict the rheology of the immiscible droplets. Specifically, can theoretically derived diagrams predict the regions over which droplets are unstable and coalesce or are stable and disperse? To explore this question, well-controlled rheological experiments will be performed on the model systems, and the results of these experiments will be compared to theoretical predictions of the rheological behavior of immiscible droplets in polymeric media. It is expected that the results of this research will enhance the understanding into the mechanisms that control the dispersion of polymer droplets into polymer melts. These findings should positively impact the production of engineered materials whose properties are optimized when the droplets are evenly dispersed throughout the blend. NON-TECHNICAL SUMMARY:Tremendous opportunities exist for researchers to create advanced, lightweight materials from immiscible polymer blends made compatible with block copolymers. Copolymers, containing blocks chemically identical to the blended components, segregate to the interface between the polymers, which should produce a fine dispersion of one polymer in another. However, fine dispersions are rarely achieved in practice, because the droplets tend to coalesce, weakening the performance of the blends. To resolve this issue, researchers from the University of Virginia (UVa) and Virginia Polytechnic Institute (VPI) will collaborate. They will synthesize and formulate systems of immiscible polymers and block copolymers of academic and industrial interest, and investigate the dispersion characteristics of these systems in well-controlled experiments. A central thrust of the research is to determine whether theoretically derived phase diagrams can be used to predict the regions over which the droplets coalesce or disperse. Preliminary findings of the collaborators indicate that phase diagrams do aid in the prediction of droplet coalescence and dispersion. Funding from the NSF will be used to cement these relationships, which are important because they can be used to provide user-friendly roadmaps to engineer advanced materials such as automotive parts, medical fabrics, and insulation products. Moreover, broader impacts from the research include using the results to enhance a course on interfacial chemistry and reaching out to local schools with the goal of increasing the number and diversity of qualified engineering and science applicants to UVa and VPI.

技术摘要：研究的目的是阐明和量化二嵌段共聚物的润湿如何控制聚合物液滴在不混溶的聚合物混合物中的分散。 具体而言，将合成单分散聚二甲基氧烷 - 氧烷 - 多硅氧烷（PDMS-B-PIP）二嵌段共聚物，并且将将这些成分添加到PDMS和PIP的不混合混合物中，以配制PDMS/PMDS/PMDS-B-PIP/PIP的良好定义模型系统的配方。使用这些系统的优点是，可以在PDMS或PIP矩阵中研究液滴的合并，这取决于液滴界面处的共聚物量，这些液滴在室温下都融化。这些组件的使用将有助于确定取决于块共聚物和基质聚合物的链长的润湿相图是否可以用于预测不混溶的液滴的流变学。 具体而言，理论上得出的图可以预测哪些液滴不稳定，结合或稳定且分散的区域？ 为了探讨这个问题，将在模型系统上进行良好控制的流变学实验，并将这些实验的结果与聚合物介质中不混溶液滴的流变学行为的理论预测进行比较。 预计这项研究的结果将增强对控制聚合物液滴分散到聚合物熔体的机制的理解。这些发现应对工程材料的生产产生积极影响，当液滴均匀分散到整个混合物中时，其特性得到了优化。 非技术摘要：研究人员存在巨大的机会，可以从与块共聚物兼容的不混合聚合物混合物中创建高级，轻质的材料。共聚物在化学上与混合成分相同的共聚物分离到聚合物之间的界面，该界面应在另一种聚合物中产生一种细化的聚合物。 但是，在实践中很少实现精细的分散体，因为液滴倾向于合并，从而削弱了混合物的性能。 为了解决这个问题，弗吉尼亚大学（UVA）和弗吉尼亚理工学院（VPI）的研究人员将合作。 他们将综合并制定不混溶的聚合物的系统，并阻止学术和工业兴趣的共聚物，并在良好的控制实验中研究这些系统的分散特征。 该研究的主要目的是确定是否可以使用理论得出的相图来预测液滴合并或分散的区域。 合作者的初步发现表明，相图确实有助于预测液滴合并和分散。 NSF的资金将用于巩固这些关系，这很重要，因为它们可用于为工程师高级材料（例如汽车零件，医疗面料和绝缘产品）提供用户友好的路线图。 此外，研究的更广泛影响包括使用结果来增强界面化学的课程，并与当地学校接触，目的是增加合格的工程和科学申请人对UVA和VPI的多样性。