This literature discussion focuses upon the Science article by Coates and Waymouth reporting the synthesis of thermoplastic elastomeric polypropylene by an unbridged zirconocene. This article was the basis for the work done for my PhD thesis in the Waymouth group. The LO was written in May 2020 in honor of Bob Waymouth's 60th birthday. See the BITeS post announcing the LO here.
After completing this literature discussion, students will be able to:
- describe a thermoplastic elastomer
- describe the stereochemistry of polypropylene
- describe the relationship between catalyst structure and polypropylene stereochemistry
- apply covalent bond classification electron counting to a zirconocene
- interpret data from figures and tables
- describe the methods used by the authors to support the synthesis of isotactic-atactic stereoblock polypropylene
As usual, instructors may wish to mix-and-match questions to suit their learning goals and time constraints.
This article addresses a part of the ACS list of inorganic chemistry macromolecular, supramolecular and nanoscale (MSN) topics:
- Ziegler-Natta, metallocene catalysts for olefin polymerization - impact on industrial/materials development
This LO was implemented with a group of senior chemistry majors at USNA in Spring 2021 as part of a 1-credit seminar course that included activities reading the primary literature. All the students had already completed 1 semester of inorganic chemistry prior to the seminar course. Responses to a subset of the questions were collected via Google Form.
Students varied in their ability to answer the questions in the literature discussion. In particular, it was noticed that they did not recall the process for electron counting. This may also have been a result of having an abbreviated inorganic chemistry foundation-level course due to COVID in Spring 2020.
A recurring theme when looking at student answers to free response questions is that even in the spring semester of senior year students are often not able to generate answers that are expert-like in terms of using concepts and terminology from foundation-level courses.