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

第一部分：非技术概述嵌段共聚物是一类独特的长链分子（聚合物），其可以被设计成在薄膜中包含良好有序的物理结构，能够基于区别性的化学吸引力有效地分离分子的通道。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用于水净化和节能燃料电池车辆的膜。虽然聚合物化学家在开发用于这些应用的合成嵌段共聚物的新方法方面取得了显着进展，但由于控制分子链的嵌段状生长所需的复杂化学程序，商业成功受到限制。在该项目中，将使用一种新的物理方法，通过选择性地改性凝胶状态下的市售聚合物，以简单、经济、有吸引力的方式制造块状聚合物。 这项研究将在加速定制嵌段共聚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，并拓宽现有先进材料的基础。 该项目的研究活动具有跨学科性质，从材料化学到膜性能，将为渴望为我们国家的领导地位做出贡献的公民和研究人员提供许多教育机会，以确保更健康，更节能的全球社会。技术总结该项目将集中在一种新的方法来创建嵌段共聚物使用简单的，后聚合化学的半结晶均聚物在凝胶状态。通过引入能够使均聚物官能化的反应物，所需的化学反应被限制为仅在半结晶网络内可接近的无定形链段上反应。这种新的物理过程产生了非随机的嵌段结合的功能，是一个简单的替代复杂的聚合机制，通常采用在嵌段共聚物的合成。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物结构方面的思维方式。 通过调整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由商业上重要的聚合物产生新的嵌段离聚物中改变，用于水净化和燃料电池应用的机械坚固的膜。该项目的目标是发展控制凝胶态功能化化学所需的物理，化学和组成参数的基本理解。与无规共聚物类似物相比，凝胶态磺化离聚物的嵌段结构将在离子含量、嵌段长度分布、结晶条件和加工参数方面受到控制。将制备嵌段共聚物的膜，并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性不足的群体在内的各种研究人员具有吸引力。 教育外联活动将通过重点开展旨在确保建立一个更健康、更节能的全球社会的尖端研究，吸引所有年龄段的公民参与。

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.