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、表征和确定一类新的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柔软特性。在过去的几十年里，聚合物化学取得了显著的进步，带来了设计具有高度可控性和功能多样性的各种分子结构的能力。开发新的分子结构，以协同先进的功能和增强的弹性的特点是这项研究的主要目标。这项拟议的工作被认为是为了生产超柔性材料和超软凝胶，这些材料具有潜在的优势，可以用作润滑剂、关节软骨(膝盖或关节)替代物，以及减少力冲击的保护设备。一类新的具有瓶刷网络结构的聚合物分子将被设计和探索，这有望导致特殊的超弹性性质。这项研究将与本科生、研究生和当地社区教育的更广泛影响相结合。这将有助于培养外国语大学和国家在聚合物科学方面不断增长的研究。一项三点计划侧重于课程开发、合作活动和针对聚合物科学中代表性不足的群体的社区推广。将开展关于塑料的教育、塑料面临的挑战以及为子孙后代解决社会需求的机会，并将其与拟议的研究相结合。用于前沿材料应用的瓶刷(BB)系统的设计除了强调接枝密度外，还强调主链和侧链的聚合度。虽然这些粗糙的刻度盘作为一种开始了解这些独特架构的手段，但还有其他合成组件可能提供了一种潜在的发现新特性的手段。大多数BB系统是由乙烯基单体或降冰片烯聚合而来的，以产生各种接枝化学物质，并附着在数量极其有限的主干选项上。这项工作建议通过使用适合于通过“嫁接”方法生产BB系统的精确的聚戊二醇胺支架来扩大可能的主干化学套件。这些材料将在每五分之一碳的位置产生接枝(类似于聚降冰片烯)，但每个接枝部位之间具有灵活的橡胶状主干化学。假设随着移植物的大小增加并开始占据其周围弥漫的体积，与这种柔性主干相关的减少的库恩长度将导致放大的灵敏度。这种动态行为将通过光散射和粘弹性测量作为综合设计原则的函数来充分研究，该综合设计原则解释了前述BB系统粗表盘的变化。这一结果将被发展的BB系统的理论和计算处理所证实。考虑到橡胶一样的主干，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减振的潜在变革性材料。将实施一项三点计划，通过改进课程、合作活动和外联活动，增加外国语大学和周围社区的聚合物科学教育。本科生将修读聚合物合成方面的高级选修课。FSU年度海报会议将突出围绕聚合物科学的研究。最后，通过塑料教育展览接触周围社区的持续努力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智力优势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.