Copolymerization and Copolymers of Crude Fischer–Tropsch Mixed α-Olefins with Vinyl Acetate

The Fischer–Tropsch (FT) synthesis is widely used to convert syngas into liquid hydrocarbons containing approximately 50% long-chain α-olefins of varying carbon numbers. In this study, the untreated FT heavy oil was directly copolymerized with vinyl acetate (VAc) via free radical polymerization without pretreatments, yielding FT heavy oil-VAc (HVA) copolymers. After polymerization, liquid–liquid phase separation occurred, with the lower polymer-enriched phase containing over 95% of the HVA copolymer products. The unreacted α-olefins of heavy oil in the supernatant can be used by supplementing VAc or directly recovered from the supernatant. The resulting copolymers are light-yellow viscous liquids with number-average molar mass (Mn) tunable from 3700 g/mol to 12,900 g/mol, and exhibit low glass transition temperatures (Tg) between −2 °C and 19 °C. The copolymers were explored as a macromolecular plasticizer for poly(vinyl chloride) (PVC), and the HVA20 (containing 20 mol % α-olefins) plasticized PVC films are highly transparent (up to 90% light transmittance). At 10 phr, HVA20 copolymer lowers PVC Tg by 10 °C and shows low migration in water, ethanol, and n-hexane (i.e., weight loss below 4%). Overall, this work converted FT products into a functional high-value polymeric material, offering a promising utilization route for all syngas-derived resources (coal, agricultural waste, and municipal solid waste).