CAS: New Catalytic Processes for Polyolefin Sustainability and Waste Utilization

CAS：聚烯烃可持续性和废物利用的新催化工艺

• 批准号: 1955730
• 负责人: Lawrence Sita
• 金额: $ 49万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1955730&HistoricalAwards=false
• 关键词: CAS; New; Catalytic; Processes; Polyolefin

With this award, the Chemical Catalysis Program of the Division of Chemistry is supporting the research of Professor Lawrence R. Sita of the Department of Chemistry and Biochemistry at the University of Maryland. Professor Sita and his research team are developing new catalytic systems for polymerization that convert abundant and inexpensive feedstock chemicals into new polyolefin materials with defined and controllable molecular structure. The polymers prepared with this new catalyst system are designed to be added to existing polyolefin waste to improve conversion to second- or multi-use polymeric products of increased commercial value. Society’s dependence on plastics comes with a significant penalty of more than 400 million pounds of plastic waste that is introduced into the environment each year. The Sita research group is focused on finding solutions to this problem and designing new polyolefin materials that can serve as replacements for plastics with more severe environmental impacts than polyolefins. This project is providing education and training for a diverse group of undergraduate and graduate students, as the next generation of scientists and leaders for sustainable science policy. Outreach activities include a one-ton plastic recycling challenge to engage elementary and high school students in a broader understanding of the problems society faces with plastic waste. New inventions, technologies, and products that are being developed through this project have potentially significant long term impacts on polymer science and technology. Professor Sita and his research group are developing configurationally-stable, enantio-enriched transition-metal complexes that function as well-defined catalysts for the enantio- and stereoselective living coordinative chain transfer polymerization (LCCTP), co-polymerization, and cyclopolymerization of olefins and non-conjugated dienes. These new catalyzed processes are providing novel classes of highly stereoregular polyolefins with technologically-relevant physical properties. A variety of spectroscopic methods and isotopically-labeled complexes and monomers are being used to understand the mechanism of enantio- and stereoselective LCCTP to further optimize these systems. Stereoselective LCCTP is guiding the design and production of new classes of well-defined polyolefin block copolymers that undergo microphase-separation in the condensed state and that can be used as plastic waste blend compatibilizers and property modifiers.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，化学系的化学催化计划是支持教授劳伦斯R。马里兰州大学化学和生物化学系的Sita说。Sita教授和他的研究团队正在开发新的聚合催化体系，将丰富而廉价的原料化学品转化为具有确定和可控分子结构的新聚烯烃材料。用这种新的催化剂体系制备的聚合物被设计成添加到现有的聚烯烃废料中，以提高向具有增加的商业价值的二次或多次使用的聚合物产品的转化率。社会对塑料的依赖带来了每年超过4亿磅塑料废物被引入环境的重大惩罚。Sita研究小组致力于寻找解决这一问题的方法，并设计新的聚烯烃材料，以替代对环境影响比聚烯烃更严重的塑料。该项目为不同的本科生和研究生群体提供教育和培训，作为下一代科学家和可持续科学政策的领导者。外联活动包括一吨塑料回收挑战，让小学和高中学生更广泛地了解社会面临的塑料废物问题。 通过该项目开发的新发明、技术和产品对聚合物科学和技术具有潜在的重大长期影响。 Sita教授和他的研究小组正在开发构型稳定、对映体富集的过渡金属配合物，这些配合物可作为烯烃和非共轭二烯的对映体和立体选择性活性配位链转移聚合（LCCTP）、共聚和环化聚合的明确催化剂。这些新的催化工艺提供了具有技术相关物理性能的新型高度有规立构聚烯烃。各种光谱方法和同位素标记的复合物和单体被用来了解对映体和立体选择性LCCTP的机制，以进一步优化这些系统。立构选择性LCCTP是指导设计和生产的新型明确的聚烯烃嵌段共聚物，在凝聚状态下进行微相分离，并可用作塑料废物共混物相容剂和性能改性剂。该奖项反映了NSF的法定使命，并已被认为是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。

项目成果

Investigation of relative stabilities of CPAM zirconium cycloalkylmethyl vs isomeric ω-alkenyl complexes: Crystal structures of the cyclobutylmethyl and cyclopentylmethyl complexes

CPAM 环烷基甲基锆与异构α-烯基配合物的相对稳定性研究：环丁基甲基和环戊基甲基配合物的晶体结构

• DOI: 10.1016/j.poly.2022.116100
• 发表时间: 2022
• 期刊: Polyhedron
• 影响因子: 2.6
• 作者: Epshteyn, Albert;Zhang, Yonghui;Fettinger, James C.;Sita, Lawrence R.
• 通讯作者: Sita, Lawrence R.

Optical Purity as a Programmable Variable for Controlling Polyolefin Tacticity in Living Coordinative Chain Transfer Polymerization: Application to the Stereomodulated LCCTP of α,ω-Nonconjugated Dienes

光学纯度作为控制活性配位链转移聚合中聚烯烃立构性的可编程变量：在 α,β-非共轭二烯立体调制 LCCTP 中的应用

• DOI: 10.1021/acscatal.1c00633
• 发表时间: 2021
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Wallace, Mark A.;Wentz, Charlotte M.;Sita, Lawrence R.
• 通讯作者: Sita, Lawrence R.

Highly Versatile Strategy for the Production of Telechelic Polyolefins

遥爪聚烯烃生产的高度通用策略

• DOI: 10.1021/acsmacrolett.2c00108
• 发表时间: 2022
• 期刊: ACS Macro Letters
• 影响因子: 7.015
• 作者: Burkey, Aaron A.;Fischbach, Danyon M.;Wentz, Charlotte M.;Beers, Kathryn L.;Sita, Lawrence R.
• 通讯作者: Sita, Lawrence R.

Migratory Insertion into a Hafnium–Phenyl Bond and a Ligand-Assisted Mechanism for Reversible Chain Transfer in the Living Coordinative Polymerization of Olefins

烯烃活性配位聚合中铪苯基键的迁移插入和配体辅助的可逆链转移机制

• DOI: 10.1021/acs.organomet.2c00364
• 发表时间: 2022
• 期刊: Organometallics
• 影响因子: 2.8
• 作者: Kuzminski, Brendan R.;Fischbach, Danyon M.;Yap, Glenn P.;Sita, Lawrence R.
• 通讯作者: Sita, Lawrence R.