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

职业生涯：利用精密大分子引发剂弥合洗瓶刷和梳状聚合物之间的差距，生成新的弹性材料

基本信息

批准号：
1750852
负责人：
Justin Kennemur
金额：
$ 53.4万
依托单位：
Florida State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-06-01 至 2025-05-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1750852&HistoricalAwards=false
关键词：
CAREER Bridging Gap Between Bottlebrush

项目摘要

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.

非技术摘要在这个项目中，PI 和他的学生将合成、表征和确定可能具有超弹性或超柔软特性的新型高性能弹性聚合物的各种材料特性。过去几十年来，聚合物化学取得了显着进步，使得设计具有高度控制性和多功能性的各种分子结构成为可能。本研究的主要目标是开发能够协同先进功能和增强弹性特征的新分子结构。拟议的工作假设生产超柔性材料和超软凝胶，它们具有潜在的优越性，可用作润滑剂、关节软骨（膝盖或关节）替代品以及减少力冲击的防护设备。将设计和探索一类具有瓶刷网络形状的新型聚合物分子结构，这有望带来特殊的超弹性特性。这项研究将与本科生、研究生和当地社区的教育更广泛的影响相结合。它将有助于培育佛罗里达州立大学和国家不断发展的聚合物科学研究。一项三点计划侧重于针对聚合物科学领域代表性不足的群体的课程开发、协作活动和社区外展。将开展有关塑料、其挑战以及解决子孙后代社会需求的机会的教育，并将其与拟议的研究相结合。技术概要用于前沿材料应用的洗瓶刷 (BB) 系统的设计除了接枝密度外，还强调主链和侧链的聚合度。尽管这些粗糙的表盘可以作为开始理解这些独特架构的一种手段，但还有其他合成成分可能提供一种潜在的发现新特性的手段。大多数 BB 系统源自乙烯基单体或降冰片烯的聚合，以产生固定在数量极其有限的主链选项上的各种接枝化学物质。这项工作建议通过使用适合通过“嫁接”方法生产 BB 系统的精确聚戊烯支架来扩展可能的主链化学套件。这些材料将恰好每五个碳原子产生一个接枝物（类似于聚降冰片烯），但在每个接枝位点之间具有柔性橡胶状主链化学结构。据推测，随着移植物尺寸的增加并开始占据其周围的体积，与这种柔性主干相关的库恩长度的减少将导致灵敏度增强。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理的函数进行充分研究，从而阐明上述 BB 系统粗调表盘的差异。结果将通过开发 BB 系统的理论和计算处理方法得到证实。考虑到类似橡胶的主干，将探索此类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材料。将实施一项三点计划，通过加强课程、合作活动和外展活动来加强佛罗里达州立大学和周边社区的高分子科学教育。本科生将学习聚合物合成方面的高级选修课。佛罗里达州立大学年度海报会议将重点介绍以聚合物科学为重点的研究。最后，通过塑料教育展览继续努力接触周围社区，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价值和更广泛的影响进行评估，被认为值得支持审查标准。