Functionalized Polypropylenes: A Copolymerization and Postmodification Platform
Alexander Evans, Oliver Casale, Louis J. Morris, Zoë R. Turner, Dermot O’Hare
Abstract
High Resolution Image Download MS PowerPoint Slide Functional polypropylenes (FPs) are regarded as versatile building blocks for next-generation materials; however, their development has been stymied due to current synthetic limitations. Here, we report a diverse range of functionalized polypropylenes prepared via a two-step copolymerization−postmodification strategy. Solution-phase copolymerization of propylene and 11-bromo-1-undecene using C 2, C 1, and C s -symmetric catalysts-afforded poly(propylene)- co -(11-bromo-1-undecene), with tunable comonomer incorporation levels, up to 15.5 mol %, with a range of tacticities ( iso-, syndio-, and atactic ) and a wide molecular weight span (4−212 kg mol −1 ). The latent electrophilic reactivity of the pendent bromide has been utilized in one of three general synthetic routes, enabling the incorporation of an array of polar substituents through the formation of a series of covalent connections (C−O, C−N, C−S, C−P, and C−C). The resulting FPs display distinctly altered bulk and surface properties, compared to polypropylene: improved thermal stability and adhesion to metal, altered wettability, and latent reactivity. This strategy allows access to FPs with both high molecular weight and chosen tacticity, taking advantage of well-developed metallocene catalysts and classical organic substitution chemistry.