Functionalized\nPolypropylenes: A Copolymerization\nand Postmodification Platform

Functional polypropylenes (FPs) are regarded as versatile\nbuilding\nblocks for next-generation materials; however, their development has\nbeen stymied due to current synthetic limitations. Here, we report\na diverse range of functionalized polypropylenes prepared via a two-step\ncopolymerization−postmodification strategy. Solution-phase\ncopolymerization of propylene and 11-bromo-1-undecene using <i>C</i><sub>2</sub>, <i>C</i><sub>1</sub>, and <i>C</i><sub><i>s</i></sub>-symmetric catalysts-afforded\npoly(propylene)-<i>co</i>-(11-bromo-1-undecene), with tunable\ncomonomer incorporation levels, up to 15.5 mol %, with a range of\ntacticities (<i>iso-</i>, <i>syndio-</i>, and <i>atactic</i>) and a wide molecular weight span (4−212\nkg mol<sup>−1</sup>). The latent electrophilic reactivity of\nthe pendent bromide has been utilized in one of three general synthetic\nroutes, enabling the incorporation of an array of polar substituents\nthrough the formation of a series of covalent connections (C−O,\nC−N, C−S, C−P, and C−C). The resulting\nFPs display distinctly altered bulk and surface properties, compared\nto polypropylene: improved thermal stability and adhesion to metal,\naltered wettability, and latent reactivity. This strategy allows access\nto FPs with both high molecular weight and chosen tacticity, taking\nadvantage of well-developed metallocene catalysts and classical organic\nsubstitution chemistry.