RAFT Step-Growth Polymerization

在化学系大分子、超分子和纳米化学项目的支持下，查佩尔山的北卡罗来纳州大学的魏佑博士将探索一种新的聚合方法，该方法将允许通过普遍适用的过程在其主链中轻松构建嵌入功能性的聚合物。该项目的成功将导致一种简单而简便的方法来设计具有精确定义的结构的功能性大分子，为广泛的应用提供新的机会。教育、合作和推广是这个项目的组成部分。参与该项目的所有学员将精通有机和聚合物合成以及各种表征。在过去的15年里，你的研究小组已经成功地招募了学生的代表性不足的群体进入研究，并已开发和监督实验室练习，初中和高中学生通过各种教育计划在斯坦福大学。在高分子化学中，自由基中心聚合几乎等同于链增长机制。作为最重要的可控自由基聚合之一，可逆加成断裂链转移（RAFT）聚合由于其通过添加被称为RAFT试剂的链转移剂（CTA）来控制自由基聚合物的聚合度（DP）的简单性和通用性而被广泛采用。然而，传统RAFT的链增长性质所固有的，这种聚合物的主链通常仅由惰性碳原子组成，而所需的官能度通过侧基引入。这与通常提供多官能杂原子主链的逐步生长聚合形成对比，其可以容易地允许将官能团引入主链中。You小组最近发现了一种实现RAFT逐步增长聚合的独特方法。基于已有的重要成果，本项目旨在进一步探索这一令人兴奋的新聚合方法，其目标有两个：（1）建立RAFT逐步增长聚合的一般原理和机理，并扩展RAFT逐步增长聚合的化学性质;（2）了解反应条件对RAFT逐步增长聚合的影响。 如果成功，该项目将构建重要步骤，以实现建立一种新的聚合方法的长期目标，RAFT逐步增长聚合，更广泛地使用，使以前无法实现的新材料的合成成为可能。该奖项反映了NSF的法定使命，并已被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Dr. Wei You of the University of North Carolina at Chapel Hill will explore a new polymerization method that will allow the facile construction of polymers with embedded functionality in their backbone through a generally applicable process. The success of this project will lead to a simple and facile methodology of designing functional macromolecules with precisely defined architectures, unlocking new opportunities for broad applications. Education, collaboration, and outreach are integral aspects of this project. All trainees involved in this project will become proficient in organic and polymer syntheses, and a variety of characterizations. For the past fifteen years, the You research group has successfully recruited students of underrepresented groups into research, and has developed and supervised laboratory exercises for middle and high-school students through various educational programs at UNC. In polymer chemistry, free radical-centered polymerizations are almost synonymous to the chain-growth mechanism. As one of the most important controlled free-radical polymerizations, Reversible-Addition Fragmentation chain Transfer (RAFT) polymerization has been widely adopted due to its simplicity and versatility of controlling the degree of polymerization (DP) of free radical polymers, enabled by the addition of chain transfer agents (CTAs) known as the RAFT agents. However, inherent to the chain-growth nature of conventional RAFT, the backbone of such polymers usually consists of only inert carbon atoms, while desired functionality is introduced through the pendent groups. This contrasts to step-growth polymerization that typically offers multifunctional heteroatom backbones, which can easily allow the introduction of functionalities into the backbone. The You group recently discovered a unique approach to achieve RAFT step-growth polymerization. Building upon significant results, this project aims to further explore this exciting new polymerization, with two objectives: (1) to establish the general principle and mechanism of RAFT step-growth polymerization and expand the expand the chemistry with other RAFT agents and monomer family; and (2) to understand the impact of reaction conditions on the RAFT step-growth polymerization. If successful, this project will construct important steps to achieve the long-term goal of establishing a new polymerization methodology, RAFT step-growth polymerization, for broader use to enable synthesis of new materials that were previously unachievable.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.