Friedel-Crafts Reaction with Polyolefins as Alkylation Reagents and Poly(vinyl chloride) as Initiator

Chemical upcycling of waste plastic has attracted substantial attention. While current upcycling methods are typically successful in converting single-component plastic waste, conversion of mixed plastics resembling real-world plastic waste with a single catalytic system remains a challenge. In this manuscript, we report an upcycling method suitable for a range of polyolefins (including mixtures of PP, LDPE, HDPE, and PVC, the four most produced plastics), which selectively produces toluene, ethylbenzene, cumene, and propylbenzene in the presence of benzene. The generation of ethylbenzene and cumene as major upcycling products, currently produced from ethylene or propylene and benzene, effectively circumvents the thermodynamically unfavorable depolymerization of polyolefins, allowing polyolefins to function as olefin surrogates in organic transformations. The utilization of inexpensive AlCl₃ as a pre-catalyst, tolerance to additives, and mild reaction conditions render this method readily adapted by the current industry setup. Therefore, this upcycling method may have some significant impact on the mitigation of the waste plastic crisis.