Blocky Copolymers via Gel-State Functionalization of Semi-Crystalline Polymers

第1部分：非技术总和嵌段共聚物是一类独特的长链分子(聚合物)，可设计为在薄膜中包含有序的物理结构，能够根据区分的化学吸引力有效地分离分子通道。由于能够精确控制这些物理结构的尺寸和化学组成，嵌段共聚物的新兴应用包括水净化膜和高能效燃料电池汽车。虽然聚合物化学家在开发用于这些应用的嵌段共聚物的新方法方面取得了显著进展，但由于控制分子链的嵌段状生长所需的复杂的化学过程，商业成功一直受到限制。在这个项目中，将使用一种新的物理方法，通过选择性地修改凝胶状态下的商业可用聚合物，以一种简单、经济上有吸引力的方式创建嵌段聚合物。这项研究将在加快定制嵌段共聚聚合物组件的创建方面取得重大进展，并增强实现下一代膜技术所需的基本洞察力，并扩大现有先进材料的基础。该项目研究活动的跨学科性质，从材料化学到膜性能，将为一个多样化的公民和研究人员社区提供许多教育机会，他们渴望为我国在确保更健康、更节能的全球社会中的领导地位做出贡献。第2部分：技术总结本项目将专注于一种新的方法，利用凝胶状态下的半结晶均聚物进行简单的后聚合化学反应来创建嵌段共聚物。随着能够使均聚物官能化的反应物的引入，所需的化学反应仅限于在半结晶网络中可访问的无定形链段上进行反应。这一新的物理过程产生了非随机、嵌段的官能团结合，是传统用于合成嵌段共聚物的复杂聚合机制的简单替代。这种方法的技术进步植根于纯物理聚合物化学的基本原理，并明显改变了我们在创建嵌段共聚体系结构方面的思维方式。通过定制半结晶凝胶的形态参数，官能化和非官能化链段的含量和尺寸将在从具有商业重要性的聚合物中创建新的块状离聚体时发生变化，用于水净化和燃料电池应用的机械坚固的膜。该项目的目标是对控制凝胶状态官能化化学所需的物理、化学和组成参数有一个基本的了解。与无规共聚物类似物相比，凝胶状态磺化离聚体的嵌段结构将受到离子含量、嵌段长度分布、结晶条件和工艺参数的控制。将制备嵌段共聚物膜，并将其与模型膜系统进行比较，以便于设计用于能量转换和水净化应用的结构量身定制的膜。该项目研究活动的跨学科性质，从材料化学到膜性能，已被证明对包括代表不足的群体在内的不同研究人员群体具有吸引力。教育宣传活动将通过关注旨在确保更健康、更节能的全球社会的尖端研究，吸引所有年龄段的公民。

PART 1: NON-TECHNICAL SUMMARYBlock copolymers are a unique class of long-chain molecules (polymers) that can be designed to contain well-ordered physical structures in thin films capable of efficiently separating the passage of molecules based on discriminating chemical attractions. Due to the ability to precisely control the size and chemical make-up of these physical structures, emerging applications of block copolymers include membranes for water purification and energy-efficient fuel cell vehicles. While polymer chemists have made remarkable progress in developing new ways to synthesize block copolymers for these applications, commercial success has been limited due to the complex chemical procedures needed to control the block-like growth of the molecular chains. In this project, a new physical approach will be used to create blocky polymers in a straightforward, economically attractive fashion by selectively modifying commercially available polymers in the gel state. This research will provide significant advancements in accelerating the creation of tailored block copolymer assemblies and enhance fundamental insight needed to enable next-generation membrane technologies and broaden the base of advanced materials available. The interdisciplinary nature of research activities in this project, ranging from materials chemistry to membrane properties, will provide many educational opportunities to a diverse community of citizens and researchers eager to contribute to our nation's leadership in ensuring a healthier, more energy-efficient global society.PART 2: TECHNICAL SUMMARYThis project will focus on a new way to create blocky copolymers using straightforward, post polymerization chemistries on semi-crystalline homopolymers in the gel state. With the introduction of reactants capable of functionalizing the homopolymer, the desired chemistry is restricted to reaction upon only the accessible amorphous chain segments within the semi-crystalline network. This new physical process yields a non-random, blocky incorporation of functionality, and is a simple alternative to the complex polymerization mechanisms that are conventionally employed in the synthesis of block copolymers. The technical advancement of this approach is rooted in the fundamentals of pure physical polymer chemistry, and clearly transforms our way of thinking with respect to the creation of blocky copolymer architectures. By tailoring the morphological parameters of the semi-crystalline gel, the content and dimensions of functionalized and non-functionalized chain segments will be altered in the creation of new blocky ionomers from commercially important polymers for mechanically robust membranes targeted for water purification and fuel cell applications. The goals of this project are to develop a fundamental understanding of the physical, chemical, and compositional parameters needed to control the gel-state functionalization chemistry. In comparison to random copolymer analogs, the blocky architecture of gel-state sulfonated ionomers will be controlled with respect to ion content, block length distribution, crystallization conditions, and processing parameters. Membranes of the blocky copolymers will be prepared and compared to model membrane systems in order to facilitate the design of architecturally tailored membranes for energy conversion and water purification applications. The interdisciplinary nature of research activities in this project, ranging from materials chemistry to membrane properties, has proven to be attractive to a diverse community of researchers, including underrepresented groups. Educational outreach activities will engage citizens of all ages through the focus on cutting-edge research aimed at ensuring a healthier, more energy-efficient global society.