CAS: Diastereoselective Polymerization Catalysis for Stereo-Sequenced Polymers with Biodegradability and Chemical Circularity

CAS：具有生物降解性和化学循环性的立体序列聚合物的非对映选择性聚合催化

• 批准号: 1955482
• 负责人: Eugene Chen
• 金额: $ 49万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1955482&HistoricalAwards=false
• 关键词: CAS; Diastereoselective; Polymerization; Catalysis; Stereo

With this award, the Chemical Catalysis Program of the NSF Division of Chemistry is supporting the research of Professor Eugene Chen in the Department of Chemistry at Colorado State University. Professor Chen is designing catalyst systems for the synthesis of advanced polymeric materials that are biodegradable and chemically circular (can be deconstructed back into their component parts). The central goal of this program is to develop polymerization catalysts that can directly convert mixtures of monomer diastereomers (molecules that have the same bond connections but different three-dimensional structure) into new high-performance biodegradable materials with defined three-dimensional structure. Deconstruction of the polymers into fragments that can be joined back together into monomers is also being studied. This work is developing new catalytic processes for the atom- and energy-efficient synthesis of polymeric materials. The proposed research encompasses diverse areas of the chemical sciences, materials engineering, and sustainability, thereby providing an excellent opportunity for the training and teaching of students, including underrepresented and undergraduate students. This project also addresses the critical need to improve polymer recyclability and Professor Chen is emphasizing the importance of this sustainability issue in workshops, lectures, and presentations. New catalysts that can polymerize diastereomeric mixtures of monomers at any rac/meso ratio into stereo-sequenced polymers have the potential to transform the synthesis of high-performance crystalline materials. Diastereoselective polymerization not only avoids the material loss and added energy costs associated with diastereomeric pre-separation and purification required by traditional stereoselective polymerization methods, but also utilizes all of the diastereomers in a mixture to modulate material properties. This study is advancing diastereoselective polymerization catalysis to achieve direct polymerization of diastereomeric monomer mixtures into isotactic/syndiotactic stereo-sequenced biodegradable crystalline polymers. The approach involves designing diastereomer-selective and earth-abundant catalysts as well as examining catalyst structure–selectivity relationships via a combined experimental and theoretical approach. Furthermore, catalysis-enabled chemical circularity of the synthesized polymers is being developed to transform these materials back to their monomers, thus closing the loop of their life cycles. This program uses a rational catalyst/monomer design approach to advance polymeric materials and methodologies by emphasizing fundamental concepts related to ditacticity and diastereoselectivity. These studies serve as an excellent training ground for aspiring undergraduate, graduate, and postdoctoral chemists of diverse backgrounds.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.

有了这个奖项，NSF化学部的化学催化计划正在支持科罗拉多州立大学化学系的尤金Chen教授的研究。陈教授正在设计用于合成先进聚合物材料的催化剂系统，这些材料是可生物降解的和化学循环的（可以被解构成它们的组成部分）。该计划的中心目标是开发聚合催化剂，可以直接将单体非对映异构体（具有相同键连接但不同三维结构的分子）的混合物转化为具有明确三维结构的新型高性能生物降解材料。将聚合物分解成可以重新连接成单体的片段也在研究中。这项工作正在开发新的催化工艺，用于原子和能量效率高的聚合物材料合成。拟议的研究涵盖化学科学，材料工程和可持续发展的各个领域，从而为学生的培训和教学提供了极好的机会，包括代表性不足的学生和本科生。该项目还解决了提高聚合物可回收性的迫切需要，陈教授在研讨会，讲座和演讲中强调了这一可持续性问题的重要性。新的催化剂可以将任何外消旋/内消旋比例的单体的非对映异构体混合物转化为立体有序聚合物，具有改变高性能结晶材料合成的潜力。非对映选择性聚合不仅避免了与传统立体选择性聚合方法所需的非对映异构体预分离和纯化相关的材料损失和增加的能量成本，而且还利用混合物中的所有非对映异构体来调节材料性质。本研究是推进非对映选择性聚合催化，实现直接聚合的非对映异构体的单体混合物成全同立构/间同立构立体序列的可生物降解的结晶聚合物。该方法包括设计非对映体选择性和地球丰富的催化剂，以及通过实验和理论相结合的方法研究催化剂结构选择性的关系。此外，正在开发合成聚合物的催化化学循环，以将这些材料转化回其单体，从而关闭其生命周期的循环。该计划使用合理的催化剂/单体设计方法，通过强调与双规度和非对映选择性相关的基本概念来推进聚合物材料和方法。这些研究为不同背景的有抱负的本科生、研究生和博士后化学家提供了一个很好的培训基地。该奖项反映了NSF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。

项目成果

Sustainable nanofiltration membranes based on biosourced fully recyclable polyesters and green solvents

• DOI: 10.1016/j.memlet.2022.100016
• 发表时间: 2022-05-01
• 期刊: JOURNAL OF MEMBRANE SCIENCE LETTERS
• 作者: Hardian, Rifan;Cywar, Robin M.;Szekely, Gyorgy
• 通讯作者: Szekely, Gyorgy

Chemically circular, mechanically tough, and melt-processable polyhydroxyalkanoates

化学循环、机械坚韧且可熔融加工的聚羟基链烷酸酯

• DOI: 10.1126/science.adg4520
• 发表时间: 2023
• 期刊: Science
• 影响因子: 56.9
• 作者: Zhou, Li;Zhang, Zhen;Shi, Changxia;Scoti, Miriam;Barange, Deepak K.;Gowda, Ravikumar R.;Chen, Eugene Y.-X.
• 通讯作者: Chen, Eugene Y.-X.

Alternating Isotactic Polyhydroxyalkanoates via Site- and Stereoselective Polymerization of Unsymmetrical Diolides

通过不对称二烯化合物的位点和立体选择性聚合制备交替全同立构聚羟基脂肪酸酯

• DOI: 10.1021/jacs.2c08791
• 发表时间: 2022
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Zhang, Zhen;Shi, Changxia;Scoti, Miriam;Tang, Xiaoyan;Chen, Eugene Y.-X.
• 通讯作者: Chen, Eugene Y.-X.

Crystalline aliphatic polyesters from eight‐membered cyclic (di)esters

• DOI: 10.1002/pol.20220418
• 发表时间: 2022-10
• 期刊: Journal of Polymer Science
• 影响因子: 3.4
• 作者: X. Tang;Changxia Shi;Zhen Zhang;E. Chen

Synthetic Biodegradable Polyhydroxyalkanoates (PHAs): Recent Advances and Future Challenges

• DOI: 10.1016/j.progpolymsci.2022.101608
• 发表时间: 2022-09
• 期刊: Progress in Polymer Science
• 影响因子: 27.1
• 作者: Andrea H. Westlie;Ethan C. Quinn;Celine R. Parker;E. Chen