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Telechelic polymers, polymers with two reactive end-groups, are sought after for their role in synthesizing macromolecules with complex structures such as multiblock copolymers and graft polymers. Many strategies for the synthesis of telechelic polymers from vinyl monomers using controlled radical polymerizations and anionic polymerizations exist. However, polyolefins—which account for the major fraction of polymer production—are not easily synthesized with two reactive end-groups. This difficulty is related to the sensitivity of olefin polymerization catalysts and their propensity for intramolecular chain transfer reactions. As a result, the most common strategies to access telechelic polyethylene and polypropylene (the two major polyolefins) do not rely on the insertion polymerization of ethylene nor propylene but rather on the polymerization of dienes or cyclic olefins. Nonetheless, recent advances in insertion polymerization and post-polymerization functionalization have resulted in the emergence of novel synthetic methods to access telechelic polyolefins. We here present a comprehensive review of all of these strategies to synthesize telechelic polyolefins.
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Amphiphilic Triblock Copolymers Containing Polypropylene as the Middle Block
Abstract The synthesis of stereoregular telechelic polypropylene (PP) and their use to access triblock amphiphilic copolymers with the PP block located in the center is described. The strategy consists of selectively copolymerizing propylene and a di‐functional co‐monomer (1,3‐diisopropenylbenzene) to yield a α,ω‐substituted polypropylene. Initiation of the copolymerization favors insertion of DIB over propylene; propagation steps favor insertion of propylene. Termination via a chain‐transfer reaction yields the terminal unsaturation of the polymer. The telechelic polypropylene is then converted into α,ω‐hydroxyl‐terminated polypropylene and used as a macroinitiator for the synthesis of triblock copolymers. Water‐soluble amphiphilic triblock polymers are also synthesized. The use of catalytic reactions simultaneously provides the stereocontrol of the polypropylene and high productivity (multiple chains of block copolymer per metal center).
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- Award ID(s):
- 1706911
- PAR ID:
- 10235903
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 51
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 22983-22988
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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