CAREER: Precise Synthesis of Polymers with Tunable Properties Through Stereocontrolled Olefin Metathesis

在化学学部大分子、超分子和纳米化学项目的支持下，德克萨斯农工大学的Quentin Michaudel正在开发一种催化方法，这种方法将使聚合物在几个大分子家族中具有特定的主链立体化学。立体化学是化学的一个分支，研究分子中原子的三维空间排列及其操纵。本研究将首先进行系统的研究，设计基于钌的高效金属催化剂并优化反应条件。开发的合成路线将用于制备各种立体规则聚合物，包括工业上相关的聚酯和聚碳酸酯。最后，聚合物的立体规则性与它们的热性能和机械性能以及可降解性有关。教育计划将通过扩大接受化学教育的机会来补充和扩大研究工作。将为患有自闭症谱系障碍的学生提供实验机会。研究小组亦会透过与本地支援自闭症儿童及其家庭的团体外展活动，培养公众的认识和包容性。这些活动将包括参观德克萨斯农工大学的化学系和以聚合物科学为重点的演示。通过与Aggie ACHIEVE（高等包容性教育和职业经验的学术课程）项目的合作，将使残疾学生接触科学。本项目将侧重于利用开环复分解聚合（ROMP）和无环二烯复分解（ADMET）进行立体控制聚合。各种单体将在依赖于立体选择性钌催化剂和外部刺激（光、温度和外源试剂）组合的过程中进行研究，以产生具有可变但可预测的主链烯烃顺反比的大分子。刺激将提供一个外部杠杆，通过激活重复单元、催化剂或链端来调节烯烃主链的整体立体化学。概述的工艺有可能对许多聚合物家族的3D结构提供高水平的控制，并允许系统地研究烯烃立体化学对合成软材料的热、机械和光学/电子性质的影响。该奖项反映了美国国家科学基金会的法定使命，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。

With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Quentin Michaudel of Texas A&M University is developing catalytic methods that will provide access to polymers with specific main-chain stereochemistry across several families of macromolecules. Stereochemistry is a branch of chemistry that is concerned with the study of 3D spatial arrangements of atoms in a molecule and the manipulation thereof. In this research, systematic studies will first be conducted to design efficient metal catalysts based on ruthenium and optimize reaction conditions. The developed synthetic routes will then be utilized to prepare a variety of stereoregular polymers, including industrially relevant polyesters and polycarbonates. Finally, the stereoregularity of polymers is to be correlated with their thermal and mechanical properties, as well as their degradability. The education plan will complement and amplify research efforts by broadening access to chemical education. Laboratory opportunities will be built for students with autism spectrum disorder. The research team will also foster awareness and inclusiveness through outreach with local support groups supporting autistic children and their families. The activities will include visits to the chemistry department at Texas A&M University and demonstrations focused on polymer science. Additional outreach will expose students with disabilities to science through collaboration with the Aggie ACHIEVE (academic courses in higher inclusive education and vocational experiences) program developed at the university. This project will focus on the development of stereocontrolled polymerizations utilizing ring-opening metathesis polymerization (ROMP) and acyclic diene metathesis (ADMET). A variety of monomers will be investigated in processes relying on a combination of stereoselective ruthenium catalysts and external stimuli (light, temperature, and exogenous reagents) to yield macromolecules with variable, yet predictable, cis:trans ratios of olefins in the main chain. The stimuli will provide an external lever with which to modulate the overall stereochemistry of the olefinic backbone through activation of either the repeating units, the catalyst, or the chain end. The outlined processes have the potential to provide a high level of control over the 3D architecture of many families of polymers and should permit systematic studies of the influence of alkene stereochemistry upon the thermal, mechanical, and optical/electronic properties of the synthesized soft materials.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.