CAREER: Bridging the Gap Between Bottlebrush and Comb Polymers with Precision Macroinitiators to Generate New Elastomeric Materials

非技术总结在这个项目中，PI和他的学生将合成，表征和确定一种新型高性能弹性聚合物的各种材料特性，这些聚合物可能具有超弹性或超软特性。在过去的几十年里，聚合物化学的显著进步已经带来了设计具有高度控制和功能多功能性的各种分子结构的能力。开发新的分子结构，协同先进的功能和增强弹性的特点是这项研究的主要目标。假设所提出的工作是生产超柔性材料和超软凝胶，这些材料和凝胶可能是上级的，并且可以用作润滑剂、关节软骨（膝盖或关节）替代物和减少力冲击的保护设备。 我们将设计和探索一类具有瓶刷网络形状的聚合物分子结构，这有望导致特殊的超弹性性能。这项研究将与教育对本科生，研究生和当地社区的更广泛影响相结合。 它将有助于促进FSU和国家在聚合物科学方面不断增长的研究。 一个三点计划的重点是课程开发，合作活动，并针对在聚合物科学代表性不足的群体社区推广。 有关塑料的教育，他们的挑战，以及他们为后代解决社会需求的机会将与拟议的研究相结合。用于前沿材料应用的瓶刷（BB）系统的设计除了接枝密度之外还强调主链和侧链的聚合度。虽然这些粗糙的表盘作为开始理解这些独特结构的一种手段，但还有其他合成组件可能提供一种潜在的发现新特性的手段。大多数BB系统衍生自乙烯基单体或异丙基烯的聚合，以产生附着到高度有限数量的主链选择的各种接枝化学。这项工作提出了通过使用精确的聚戊烯支架来扩展可能的骨架化学套件，该支架适合于通过“嫁接”方法产生BB系统。这些材料将在每五个碳原子上产生一个接枝物（类似于聚异丁烯），但在每个接枝位点之间具有灵活的橡胶状骨架化学。据推测，减少库恩长度与这个灵活的骨干将导致放大的灵敏度作为移植物的大小增加，开始占据周围的弥漫体积it.Such动态行为将通过光散射和粘弹性测量作为一个功能的合成设计原则，阐明在上述粗拨号BB系统的差异进行充分研究。研究结果将与发展BB系统的理论和计算处理相证实。鉴于橡胶状的骨干，将探索这种系统向超弹性和超软网络的自然延伸，以提供用于润滑和冲击阻尼的潜在变革性材料。将实施一个三点计划，通过加强课程，合作活动和外展活动，增加FSU和周边社区的聚合物科学教育。本科生将提供高分子合成的高级选修课。围绕聚合物科学的研究将突出FSU年度海报会议。最后，通过塑料教育展览，持续努力向周围社区推广，将揭示涉及聚合物科学的社会方面。该奖项反映了NSF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。

NON-TECHNICAL SUMMARYIn this project the PI and his students will synthesize, characterize, and determine a variety of material properties for a new class of high-performance elastic polymers that may have super-elastic or super-soft properties. Prominent advances in polymer chemistry over the last several decades have ushered in the ability to design a variety of molecular architectures with a high degree of control and functional versatility. The development of new molecular architectures that synergize the features of advanced functionality and enhanced elasticity is the primary objective of this research. The proposed work is hypothesized to produce ultra-flexible materials and super-soft gels that are potentially superior and could have applications as lubricants, articular cartilage (knee or joint) replacements, and protective equipment that reduces force impact. A new class of architectures of polymer molecules having bottlebrush-network shapes will be designed and explored, which is expected to lead to special super-elastic properties. This research will be integrated with broader impacts of education for undergraduates, graduates, and the local community. It will contribute to nurturing the growing research in polymer science at FSU and the nation. A three-point plan focuses on curriculum development, collaborative events, and community outreach directed towards underrepresented groups in polymer science. Education about plastics, their challenges, and their opportunities to solve societal needs for future generations will be undertaken and integrated with the proposed research. TECHNICAL SUMMARY The design of bottlebrush (BB) systems for frontier materials applications places emphasis on the degree of polymerization of the backbone and the side chains in addition to graft density. Although these coarse dials serve as a means to begin understanding of these unique architectures, there are other synthetic components which may present a means potentially to discover new properties. A majority of BB systems are derived from the polymerization of either a vinyl monomer or norbornene to produce a variety of graft chemistries affixed to a highly limited number of backbone options. This work proposes to expand the suite of backbone chemistries possible through the use of precise polypentenamer scaffolds suited to produce BB systems through a "grafting-from" approach. These materials will produce a graft at exactly every fifth carbon (similar to polynorbornenes) but with a flexible rubber-like backbone chemistry between each graft site. It is hypothesized that the reduced Kuhn length associated with this flexible backbone will result in amplified sensitivity as the size of the grafts increase and begin to occupy the pervaded volume around it. Such dynamic behavior will be fully studied through light scattering and viscoelastic measurements as a function of the synthetic design principles that elucidate variances in the aforementioned coarse dials for BB systems. The results will be corroborated with developing theoretical and computational treatments for BB systems. Given the rubber-like backbone, a natural extension for such systems towards superelastic and supersoft networks will be explored to provide potentially transformative materials for use in lubrication and impact dampening. A three-point plan will be implemented to increase the education in polymer science at FSU and the surrounding community through enhanced curriculum, collaborative events, and outreach. Undergraduates will be offered an advanced elective in polymer synthesis. Research focused around polymer science will be highlighted with an FSU annual poster session. Finally, continued efforts to reach out to the surrounding community through a plastics education exhibit will bring to light societal aspects that involve polymer science.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.