RUI: Thermal and Opto-rheological Studies of Poly(p-phenylene vinylene) (PPV) and PPV Derivatives

聚（对苯撑亚乙烯基）（PPV）和PPV衍生物因其在各种电子和光学器件应用中的潜力而受到关注。 由于最终的PPV聚合物是高度共轭的和不溶性的，优选的合成方法遵循前体聚合物路线。 这些路线被称为：锍前体路线（SPR）、黄原酸盐前体路线（XPR）和氯前体路线（CPR）。 在该项目中，PPV和PPV衍生物将根据所需产品通过这些路线中的每一种合成。 PPV将从黄原酸盐前体合成，这导致更无定形的聚合物。 对热消除反应机理和反应动力学进行了分析。 这将提供前体的半衰期（保质期），这对于聚合物的商业应用是重要的。 对热消除反应的充分理解是重要的，因为热消除反应的条件影响最终产物的性质。 将合成的其它PPV衍生物包括例如：聚（2，5-二甲氧基-对亚苯基亚乙烯基）（DM-PPV）;聚（苯氧基亚苯基亚乙烯基）（PO-PPV）和聚（2，3二苯基亚苯基亚乙烯基）（DP-PPV）。 它们的热性质将如上文针对黄原酸盐前体所讨论的那样进行分析。 此外，将采用的光流变技术被称为动态红外线性二色性（DIRLD），最近才被应用于电活性聚合物的分析。 这项研究将把分子运动（红外区的振动模式）与动态力学分析（DMA）观察到的宏观性质联系起来。学生将积极参与材料研究，从聚合物前体的合成到热分析和DIRLD表征。 本科生将与研究生和PI一起工作。 结果将在每周的小组会议上讨论，在那里可以交换意见和回答问题。 该研究将在地方，区域和国家层面上正式提交，并将出版物提交给参考期刊，以便向材料科学界传播。

Poly(p-phenylene vinylene)(PPV) and PPV derivatives are of interest for their potential in a variety of electronic and optical device applications. Because the final PPV polymer is highly conjugated and insoluble, the preferred synthetic method follows a precursor polymer route. The routes are referred to as: sulfonium precursor route (SPR), xanthate precursor route (XPR) and chlorine precursor route (CPR). In this project, PPV and PPV derivatives will be synthesized via each of these routes depending on the desired product. PPV will be synthesized from the xanthate precursor which results in a more amorphous polymer. The thermal elimination reaction mechanism and the kinetics of the reaction will be analyzed. This will provide the half-life (shelf-life) of the precursor which is important for commercial application of the polymer. A full understanding of the thermal elimination reaction is important because the conditions of the thermal elimination reaction influence the properties of the final product. Other PPV derivatives that will be synthesized include, for example: poly(2,5-dimethoxy-p-phenylene vinylene)(DM-PPV); poly(phenoxyphenylene vinylene)(PO-PPV) and poly(2,3 diphenyl phenylene vinylene)(DP-PPV). Their thermal properties will be analyzed as discussed above for the xanthate precursor. In addition, the opto-rheological technique that will be employed is referred to as dynamic infrared linear dichroism (DIRLD) and has only recently been applied to the analysis of electroactive polymers. This study will relate the molecular motions (vibrational modes in the infrared region) to the bulk macroscopic properties observed by dynamic mechanical analysis (DMA).%%%Students will be actively engaged in materials research from the synthesis of the polymer precursor through to characterization by thermal analysis and DIRLD. Undergraduate students will work with a graduate student and the PI. Results will be discussed at weekly group meetings where ideas can be exchanged and questions answered. The research will be formally presented at the local, regional and national levels with publications submitted to referred journals for dissemination to the materials science community.