Upcycled Composite Derived from Polyacrylonitrile and Elemental Sulfur: Thermomechanical Properties and Microstructural Insight

Shalini K. Wijeyatunga and Rhett C. Smith ()
Additional contact information
Shalini K. Wijeyatunga: Department of Chemistry, Clemson University, Clemson, SC 29634, USA
Rhett C. Smith: Department of Chemistry, Clemson University, Clemson, SC 29634, USA

Sustainability, 2025, vol. 17, issue 8, 1-18

Abstract: 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 ( PANS 90 ) 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 PANS 90 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 PANS 90 (0.33 kg CO 2 e/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.

Keywords: high-sulfur-content materials; inverse vulcanization; polyacrylonitrile; sulfur utilization; upcycling; thiocracking; composites (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/17/8/3702/pdf (application/pdf)
https://www.mdpi.com/2071-1050/17/8/3702/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:17:y:2025:i:8:p:3702-:d:1638089

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().