CAREER: Synthesis, Characterization, and Phase Behavior of Poly(vinyl ester) Block Copolymers

技术总结本项目的目标是开发互补的自由基聚合技术，以制备未知类别的乙烯基酯单体嵌段共聚物，并研究它们在熔融状态和稀水溶液中的相行为。熔体相行为研究将利用一系列实验方法，包括小角X射线散射、流变学和电子显微镜(扫描电子显微镜和TME)。由于联苯酯单体的批量供应，这些嵌段共聚物可以设计出可用于商品应用的具有可调流变性能的新型软材料。已知的一些乙烯基酯均聚物的生物降解性也证明了对这些新嵌段共聚物潜在的生物降解性的研究。这些研究将阐明聚合物组成与这种新单体的结构、形态和降解性之间的关系。本文开发的合成方法将扩展到能够合成定义明确的、单分散的基于聚乙烯醇的两亲嵌段共聚物。由于亲水性电晕嵌段中存在强相互作用的羟基，这些新型聚合物表面活性剂有望在稀水分散体中表现出与其他非离子表面活性剂不同的相行为和流变性。本研究中乙烯基酯嵌段共聚物的合成和物理表征的强耦合相互作用将揭示支撑主体材料性能的基本分子参数。非技术性摘要本项目的主要目标是探索一类新型纳米结构塑料的合成和性能，它可能会表现出新的降解性，并在商品和增值应用中找到用途。这些研究将作为长期努力开发生物可降解聚合物和聚合物肥皂的基础，这些聚合物肥皂可以系统地改善水等流体的流动特性。由于它们来自廉价的化学原料，人们预计这些材料可以经济地大规模生产，应用包括药物输送、可降解组织支架和其他生物医学设备、个人护理和医药产品中分散体的稳定性以及有助于提高石油采收率的表面活性剂，这将有助于提高总产量。这些研究成果将被整合到广泛的教育活动中，旨在提高对商品化学创新重要性的科学、社会和政治认识，目的是扩大未被充分代表的群体对科学、技术、工程和数学(STEM)学科的参与。该研究项目位于化学、化学工程和材料科学的交界处，将培养研究生和本科生，以应对聚合物科学中的重要挑战。研究成果将通过开发聚合物实验课程整合到本科课程中，旨在促进STEM学生之间的跨学科交流。此外，还将为中学和中学后教育工作者编写课程材料，突出商品化学品创新的更广泛的社会和政治影响。这些材料将作为包容性课程的原型，利用跨学科联系在更广泛的背景下展示科学问题，同时突出过去、现在和未来的研究和开发活动。

TECHNICAL SUMMARY The goal of this project is to develop complementary free radical polymerizatin techniques to prepare unkown classes of block copolymers derived from vinyl ester monomers and to study their phase behavior in the melt state and in dilute aqueous solutions. Melt phase behavior studies will exploit a complement of experimental methods including small-angle x-ray scattering, rheology, and electron microscopy (SEM and TME). Due to the bulk availability of binyl ester monomers, these block copolymers may enable the design of new soft materials having tunable rheological properties useful in commodity applications. The known biodegradability of some vinyl ester homopolymers also warrants invetigations into the potential biodegradability of these new block copolymers. These studies will elucidate relationships between polymer composition and architecture, morphologym and degradability for this new palette of monomers. The synthetic methods developed herein will be extended to enable the synthesis of well-defined, monodisperse poly(vinyl alcohol)-based amphiphilic block copolymers. As a consequence of the presence of strongly interacting hydroxyl groups in the hydrophilic corona block, these new polymeric surfactants are expected to exhibit different phase behaviors and rheological properties in dilute aqueous dispersions, as compared to those of other non-ionic surfactants. The strongly couple interplay of vinyl ester block copolymer synthesis and physical characterization in this research will shed light on the fundamental molecular parameters that underpin bulk materials properties. NON-TECHNICAL SUMMARY The major objective of this project is to explore the synthesis and properties of a new class of nanstructures plastics, which potentially will exhibit novel degradability and find use in both commodity and value-added applications. These studies will serve as the foundation for long-term efforts to develop biodegradable polymers as well as polymeric soaps that systematically modify the flow properties of fluids such as water. By virtue of their derivation from cheap chemical feedstocks, one anticipates that these materials may be economically produced n large scales for applications including drug delivery, degradable tissue scaffolds and other biomedical devices, stabalization of dispersions in personal care and pharmaceutical products, and surfactants for enhanced oil recovery that will help to increase overall yields. These research effots will be integrated into a wide spectrum of educational activites aimed at increasing scientific, social, and political awareness about the importance of commodity chemical innovations, with the aim of broadening participation of under-represented groups in science, technology, engineering, and mathematics (STEM) disciplines. Situated at the interface of chemistry, chemical engineering, and materials science, this research project will train both graduate and undergraduate students to tackle important challenges in polymer science. Research results will be integrated into undergraduate curricula through the development of experiments for a polymer lab course intended to foster interdisciplinary communication between STEM students. Additionally, curriculum materials for secondary and post-secondary educators highlighting the broader social and political impacts of commodity chemical innovations will be developed. These materials will serve as a prototype for inclusive curricula that employ interdisciplinary connections to cast scientific problems in captivating broader contexts, while highlighting past, present, and future research and development activities.