Determination of Fundamental Structure-Topology-Morphology-Properties for Naturally-derived Recyclable Polymer Materials Designed to Address Environmental and Societal Challenges

全球塑料污染问题正处于一个关键时刻。高分子材料（塑料）在日常用品中影响着社会，促进了安全、健康和福利，也促进了美观、愉悦和便利。虽然有些塑料材料是为了耐用和具有长期稳定性（例如轮胎、汽车塑料部件、头盔等），但在最初设计阶段应考虑整个聚合物生命周期，以便在材料功能完成后纳入可回收性机制。塑料积累和持久性对环境的负面影响正变得越来越重要。这项工作预期的广泛影响将是推动天然衍生聚合物材料的发展，这些材料被设计成具有复杂性，使它们能够表现出独特的性能，并具有内在的解聚和回收机制。重点将放在构建具有高吸水性和坚韧的水凝胶的材料上，并将进行严格的研究，以确定聚合物材料的有效性，以满足与全球水资源挑战相关的需求，以及减少摩擦、生物污垢和冰形成的技术挑战。这项工作的重要成果有望成为未来几代科学家的先进知识和意识，他们将考虑他们开发的技术的整个生命周期。第2部分:总体目标是开展基础研究，深入了解双共价和非共价（超分子）交联聚合物材料的组成-结构-拓扑-形态效应，并对开发源自天然原料的机械坚固功能聚合物感兴趣，这些聚合物被设计成具有水凝胶，防污，防冰，污染物隔离和其他各种应用的行为，解决社会挑战，同时也可回收利用，以限制材料对环境的长期不利影响。葡萄糖将作为构建拓扑复杂的滑环聚合物网络的主要构建块，具有共价和超分子相互作用，从而产生动态的、机械坚固的水凝胶行为，并进一步扩展到具有高吸水性和高孔隙率的聚合物高内相乳液（polyHIPE）材料。将进行基础研究以确定完整材料的性能，随后调查其基于解聚的可回收性和长期水解降解性。据推测，系统研究结合共价键组分、超分子主客体相互作用、滑环拓扑结构和多聚聚乙烯形态的网络将增强对组成-结构-拓扑-形态-性质关系的基本理解，并导致能够超高吸水动力学和容量的先进材料，同时表现出动态的、响应的物理化学和机械行为具有广泛的应用。重要的是，将开发利用天然原料和内置解聚和拆卸路线制造此类材料的技术，以提高可持续性和可回收性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

PART 1: NON-TECHNICAL SUMMARYThe global plastics pollution problem is at a critical point. Polymer materials (plastics) impact society in everyday products that facilitate safety, health and welfare, and also beauty, pleasure and convenience. Although some plastic materials are meant to be durable and possess long-term stability (e.g. tires, plastic parts for automobiles, helmets, etc.), the full polymer life cycle should be considered during the initial design stages, to incorporate mechanisms for recyclability once the function of the material has been completed. The negative environmental effects of plastic accumulation and persistence are becoming of increasing importance. The expected broad impact of this work will be in the advancement of naturally-derived polymer materials that are designed to possess complexities that allow for them to exhibit unique properties, and have in-built mechanisms for their depolymerization and recycling. A focus will be upon constructing the materials to behave as super-absorbent and tough hydrogels, and rigorous studies will be conducted to determine the effectiveness of the polymer materials to meet needs associated with global water resource challenges, and technological challenges of reducing friction, biofouling, and ice formation. Significant outcomes of this work are expected to be an advanced knowledge and awareness by future generations of scientists who will consider the full life cycle of the technologies that they develop. PART 2: TECHNICAL SUMMARYThe overall objective is to conduct fundamental studies that lead to advanced understanding of the composition-structure-topology-morphology effects for dual covalently and non-covalently (supramolecularly) crosslinked polymer materials, with an interest in developing mechanically-robust functional polymers that are derived from natural feedstocks and designed to exhibit hydrogel, anti-fouling, anti-icing, pollutant sequestering and other behaviors for diverse applications that address societal challenges, while also being recyclable to limit adverse environmental impacts of the materials long-term. Glucose will serve as the primary building block from which topologically-complex slide-ring polymer networks will be constructed, having both covalent and supramolecular interactions to result in dynamic, mechanically-robust hydrogel behaviors, with further extension to polymeric high internal phase emulsion (polyHIPE) materials for superabsorbency and high porosity. Fundamental studies will be performed to determine the properties of the intact materials, followed by investigation of their intentional depolymerization-based recyclability and long-term hydrolytic degradability. It is hypothesized that systematic investigation of networks that combine components of covalent linkages, supramolecular host-guest interactions, slide-ring topology and polyHIPE morphology will enhance the fundamental understanding of composition-structure-topology-morphology-properties relationships and lead to advanced materials that are capable of ultra-high water uptake kinetics and capacity, while exhibiting dynamic, responsive physicochemical and mechanical behaviors for broad applications. Importantly, techniques to build such materials from naturally-sourced feedstocks and with in-built depolymerization and disassembly routes will be developed to advance sustainability and recyclability.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.