Annually produced at a rate of 170 million tons per year, polyolefin manufacturing has changed the quality of life and planet Earth forever. Isotactic polypropylene comprises 25% of all polyolefins manufactured and is applied in countless products globally. Polypropylene and all industrially produced polyolefins are linear molecules containing chain-ends. Employing a highly active homogeneous tungsten catalyst for the ring expansion polymerization of alkynes, atactic cyclic polypropylene can now be synthesized. Characterization and confirmation of a cyclic topology comes from size exclusion chromatography, dynamic light scattering, viscometry, and rheology. Importantly, the cyclic topology of polypropylene leads to dramatic differences in the physical properties of the polymer including a &gt; 20 °C increase in its glass transition temperature (Tg) compared to the linear version. Additional polyolefins such as the bulk scale synthesis of cyclic poly-1-pentene, and the synthesis of a highly transparent cyclic version of the commodity polyolefin TPXTM, poly(4-methylpentene), will be discussed.

Catalytic synthesis and characterization of cyclic polyolefins including cyclic polypropylene

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.