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Abstract Herein, we report a selective photooxidation of commodity postconsumer polyolefins to produce polymers with in‐chain ketones. The reaction does not involve the use of catalyst, metals, or expensive oxidants, and selectively introduces ketone functional groups. Under mild and operationally simple conditions, yields up to 1.23 mol % of in‐chain ketones were achieved. Installation of in‐chain ketones resulted in materials with improved adhesion of the materials and miscibility of mixed plastics relative to the unfunctionalized plastics. The introduction of ketone groups into the polymer backbone allows these materials to react with diamines, forming dynamic covalent polyolefin networks. This strategy allows for the upcycling of mixed plastic waste into reprocessable materials with enhanced performance properties compared to polyolefin blends. Mechanistic studies support the involvement of photoexcited nitroaromatics in consecutive hydrogen and oxygen atom transfer reactions.
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Temporal Control over Two‐ and Three‐State Living Coordinative Chain Transfer Polymerization for Modulating the Molecular Weight Distribution Profile of Polyolefins
Abstract A highly versatile new strategy for manipulating the molecular weight profiles, including breadth, asymmetry (skewness) and modal nature (mono‐, bi‐, and multimodal), of a variety of different polyolefins is reported. It involves temporal control over two‐ and three‐state living coordinative chain transfer polymerization (LCCTP) of olefins in a programmable way. By changing the identity of the R′ groups of the chain transfer agent, ER′n, with time, different populations of chains within a bi‐ or multimodal polyolefin product can be selectively tagged with different end‐groups. By changing the nature of the main‐group metal of the CTA, programmed manipulation of the relative magnitudes of the dispersities of the different maxima that make up the final MWD profile can be achieved. This strategy can be implemented with existing LCCTP materials and conventional reactor methods to provide access to scalable and practical quantities of an unlimited array of new polyolefin materials.
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- Award ID(s):
- 1955730
- PAR ID:
- 10283728
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 60
- Issue:
- 36
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 19671-19678
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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