Laser‐Driven Superfast‐Heating and Quenching Approach to Selectively Upcycle Waste Polyolefin into Long‐Chain Terminal Alkenes and Functionalization

Abstract Polyolefin waste represents a vast, underexplored resource for chemical production, yet achieving high‐selectivity upcycling into valuable products remains a significant challenge. Here, a controlled depolymerization strategy—laser flash pyrolysis (LFP)—is reported to efficiently convert waste polyolefins into long‐chain terminal alkenes (LT‐alkenes) with exceptional selectivity. Leveraging superfast heating (≈10⁵ °C s −1 ) and quenching (≈6000 °C s −1 ) rates, LFP breaks through thermodynamic equilibrium constraints, directing primary C─C bond scission while suppressing secondary reactions via rapid fragment extraction. This catalyst‐free approach enables selective production of long‐chain terminal alkenes, even from highly contaminated feedstocks. The resultant long‐chain terminal alkenes can serve as versatile precursors for downstream functionalization, such as amphiphilic copolymer synthesis, expanding their utility across applications. By relying solely on sustainable electricity, this proof‐of‐concept demonstrates LFP's potential to recycle polyolefin waste streams into high‐value organic intermediates with industrial scalability and environmental sustainability.