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Abstract Rancid animal fats unsuitable for human or animal food production represent low‐value and abundant, yet underexploited organic chemical precursors. The current work describes a strategy to synthesize high sulfur‐content materials (HSMs) that directly utilizes a blend of partially hydrolyzed chicken fat and plant oils as the organic comonomers, following up on analogous reactions using brown grease in place of chicken fat. The reaction of sulfur and chicken fat with either canola or sunflower oil yielded crosslinked polymer composites CFSxor GFSx, respectively (x = wt% sulfur, varied from 85%–90%). The composites exhibited compressive strengths of 24.7–31.7 MPa, and flexural strengths of 4.1–5.7 MPa, exceeding the value of established construction materials like ordinary Portland cement (compressive strength ≥17 MPa required for residential building, flexural strength 2–5 MPa). The composites also exhibited thermal stability up to 215–224 °C. The simple single‐step protocol described herein represents a way to upcycle an affordable and previously unexploited animal fat resource to form structural composites via the atom economical inverse vulcanization mechanism.
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This content will become publicly available on April 1, 2026
Upcycled Composite Derived from Polyacrylonitrile and Elemental Sulfur: Thermomechanical Properties and Microstructural Insight
Herein, a method to upcycle polyacrylonitrile (PAN) into high-sulfur-content materials (HSMs) by reacting 10 wt. % PAN with 90 wt. % elemental sulfur at 220 °C is reported. The resulting composites (PANS90) form glassy solids that display compressive, flexural, and tensile strengths comparable to or exceeding some common construction materials, including C62 brick. Comparison to other plastic-derived HSMs indicates that PANS90 exhibits mechanical properties including compressional strength (11.4 MPa), flexural strength (3.6 MPa) and tensile strength (2.5 MPa) within a similar or slightly improved range. Mechanistic investigations using small-molecule analogs (e.g., adiponitrile) suggest that thiophene ring formation and radical-driven sulfur–carbon bond formation are key reaction pathways, contributing to the composite’s crosslinked microstructure. Preliminary life cycle assessments estimate a global warming potential for PANS90 (0.33 kg CO2e/kg) that is about three times lower than that of Ordinary Portland Cement, underscoring its reduced environmental footprint. Overall, this sulfur-based upcycling strategy addresses two pressing waste-management concerns—surplus sulfur from petroleum refining and unrecycled PAN—while furnishing robust composites suitable for applications ranging from lightweight construction materials to specialty polymer systems.
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- Award ID(s):
- 2203669
- PAR ID:
- 10650097
- Publisher / Repository:
- mdpi
- Date Published:
- Journal Name:
- Sustainability
- Volume:
- 17
- Issue:
- 8
- ISSN:
- 2071-1050
- Page Range / eLocation ID:
- 3702
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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