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DOE OSTI · 3384933

PET waste- and bio-derived imine vitrimers for shape-memory, intrinsic flame-retardant, and recyclable carbon fiber composites

Danielson, Mary K. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee-Oak Ridge Innovation Institute (UT-ORII), Knoxville, TN (United States)] (ORCID:0000000285426777)·Cortes Guzman, Karen [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000287934687)·Choi, Jihye [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0009000691318189)·Phadatare, Akash [University of Tennessee, Knoxville, TN (United States)] (ORCID:0009000058564835)·Singh, Harmandeep [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0009000727361411)·Bowland, Christopher C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000212294312)·Kertesz, Vilmos [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000301865797)·Kumar, Vipin [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000295807098)·Gainaru, Catalin [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000182956433)·Saito, Tomonori [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0000000245367530)·Rahman, Md Anisur [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000271909751)
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Abstract

Developing circular multifunctional vitrimers and carbon fiber–reinforced polymers (CFRPs) that are simultaneously recyclable, mechanically robust, and intrinsically flame retardant remains a major challenge. Here, in this study, we report multifunctional vitrimers and their carbon fiber–reinforced vitrimer (CFRV) composites, where the vitrimer design integrates closed-loop recyclability, enhanced interfacial adhesion, and intrinsic flame retardancy within a single materials platform. The vitrimer matrix is synthesized from post-consumer polyethylene terephthalate (PET) waste and a vanillin-derived phosphorus-containing crosslinker, forming an imine-based network. The resulting vitrimer resin exhibits high tensile strength, thermal healability, repeated reprocessability, programmable shape memory, and rapid chemical depolymerization under mild conditions. Amine-functionalized carbon fibers significantly improve fiber–matrix interfacial bonding, yielding CFRVs with tensile strengths up to 789 MPa and complete recovery of structurally intact fibers after chemical recycling. The phosphorus-rich aromatic network further imparts intrinsic flame retardancy, enabling self-extinguishing behavior without external additives. This work advances a materials design paradigm for next-generation multifunctional, sustainable vitrimers and CFRVs, while simultaneously addressing the recycling challenges associated with both plastic and CFRP waste.

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Bio-derived crosslinkerCarbon fiber–reinforced polymersClosed-loop recyclabilityFiber–matrix interfaceFlame retardancyImine vitrimersPET wasteShape memory

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Danielson, Mary K. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee-Oak Ridge Innovation Institute (UT-ORII), Knoxville, TN (United States)] (ORCID:0000000285426777), Cortes Guzman, Karen [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000287934687), Choi, Jihye [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0009000691318189), Phadatare, Akash [University of Tennessee, Knoxville, TN (United States)] (ORCID:0009000058564835), Singh, Harmandeep [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0009000727361411), Bowland, Christopher C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000212294312), Kertesz, Vilmos [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000301865797), Kumar, Vipin [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000295807098), Gainaru, Catalin [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000182956433), Saito, Tomonori [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States). Bredesen Center for Interdisciplinary Research and Graduate Education] (ORCID:0000000245367530), Rahman, Md Anisur [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000271909751). 2026-10-01. PET waste- and bio-derived imine vitrimers for shape-memory, intrinsic flame-retardant, and recyclable carbon fiber composites. https://doi.org/10.1016/j.compositesb.2026.113934

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Carbon composites materialBio-derived crosslinker subjectCarbon fiber–reinforced polymers subjectClosed-loop recyclability subjectFiber–matrix interface subjectFlame retardancy subjectImine vitrimers subjectPET waste subject

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