CAREER: Development of Catalytic, Sulfur-Free Chain Transfer Agents to Improve Mechanical and Material Performance of Crosslinked Photopolymers

职业：开发催化无硫链转移剂以改善交联光聚合物的机械和材料性能

• 批准号: 2240141
• 负责人: Brady Worrell
• 金额: $ 69.32万
• 依托单位: University of Denver
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2240141&HistoricalAwards=false
• 关键词: CAREER; Development; Catalytic; Sulfur; Free

With funding from the Chemical Catalysis (CAT) and Macromolecular, Supramolecular, and Nanochemistry (MSN) Programs of the Division of Chemistry (CHE), and the Polymer Program of Division of Materials Research (DMR), Brady Worrell of the University of Denver will develop a catalytic, sulfur-free chain transfer agent (CTA) for efficiently creating photopolymers. An important subset of plastics is photopolymer, or crosslinked materials created with light. Photopolymers make up the polymer component of materials commonly used in 3D printing, dentistry, and biomaterials, however, only a limited window of mechanical properties can easily be accessed from available chemical feedstocks. In the work proposed here, Dr. Worrell and his team will create catalysts that have the potential to significantly alter the mechanical properties of photopolymers while keeping 99% of the chemical composition the same. Dr. Worrell will also establish and run the Summer High school Internships: New Experimentalists at University of Denver (SHINE @ DU) program, which aims to offer local, under-represented high school students real-world research experiences hosted in the Department of Chemistry & Biochemistry. An undergraduate led online journal detailing scalable, simple, and inexpensive preparations of organic polymers is to be established as part of this CAREER award effort.The materials generated by photopolymerization are inherently highly crosslinked and suffer from significant shrinkage stress, are often brittle, and have a limited range of material properties. Various classes of chain transfer agents (CTAs) have been investigated and developed to reduce the crosslinking density of photopolymers. Although CTAs are successful in manipulating the mechanical properties of photopolymers, they are required in high loadings (up to 20 wt% of total formulation) and frequently contain sulfur which is malodorous and can create unstable formulations. Dr. Worrell and his research team are developing a catalytic, sulfur-free CTA that can be added in ppm quantities to existing commercial monomer feedstocks to create photopolymers similar to those prepared using traditional CTAs, but at 10,000x lower loadings. Several analogs of the macrocyclic cobalt(II) catalyst will be explored to improve resin solubility and various ligands will be screened in a high-throughput fashion in the search for potent catalyst:ligand combinations. These catalytic CTAs will be tested in commercial 3D printing resins and liquid crystal elastomers to narrow and reduce the glass transition temperature, reduce storage modulus, and alter other pertinent mechanical properties.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.

借助化学催化（CAT）和大分子，超分子和纳米化学（MSN）化学系（CHE）的纳米化学（MSN），丹佛大学的Brady Worrell材料研究部（DMR）的聚合物计划开发催化无硫链转移剂（CTA），以有效地产生光聚合物。塑料的一个重要子集是光聚合物或用光产生的交联材料。光聚合物构成了3D打印，牙科和生物材料通常使用的材料的聚合物成分，但是，只能从可用的化学原料中轻松获取机械性能的有限窗口。在这里提出的工作中，沃雷尔博士和他的团队将创建催化剂，这些催化剂有可能显着改变光聚合物的机械性能，同时保持99％的化学成分相同。 Worrell博士还将在丹佛大学（Shine @ DU）计划中建立和经营夏季高中实习：新实验家，该计划旨在为当地，代表性不足的高中学生提供现实世界中的现实研究经验。 ＆生物化学。本科生LED在线期刊详细介绍了有机聚合物的可扩展，简单和廉价的有机聚合物制剂，作为这项职业奖项的一部分。光聚合产生的材料本质上是高度交联的，并且遭受了严重的收缩压力，通常是脆弱的，通常是脆弱的，并且已经易碎有限的材料特性范围。已经研究并开发了各种类别的链转移剂（CTA），以降低光聚合物的交联密度。尽管CTA在操纵光聚合物的机械性能方面取得了成功，但在高负载（最高总配方占20 wt％）中需要它们，并且经常含有硫酸盐，该硫可能是出现的，可能会产生不稳定的配方。 Worrell博士和他的研究团队正在开发一种无硫的CTA，可以将PPM数量添加到现有的商业单体原料中，以创建类似于使用传统CTA的产品类似的光聚合物，但下载量较低10,000倍。 将探索大环钴（II）催化剂的几种类似物，以提高树脂溶解度，并将以高通量方式筛选各种配体以寻找有效的催化剂：配体组合。这些催化的CTA将在商业3D打印树脂和液晶弹性体中进行测试，以缩小和降低玻璃过渡温度，减少存储模量并改变其他相关机械性能。该奖项反映了NSF的法定任务，并被视为值得通过评估的支持。利用基金会的知识分子和更广泛的影响审查标准。

项目成果

Catalytic, Sulfur-Free Chain Transfer Agents That Alter the Mechanical Properties of Cross-Linked Photopolymers

可改变交联光聚合物机械性能的催化无硫链转移剂

• DOI: 10.1021/jacs.3c03811
• 发表时间: 2023
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Bagnall, Nicholas R.;Jones, Meredith H.;Jernigan, G. Cole;Routt, Chase;Dar, Lisa C.;Worrell, Brady T.
• 通讯作者: Worrell, Brady T.