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Abstract A three‐stage route to chemically upcycle post‐consumer poly(ethylene terephthalate) (PET) to produce high compressive strength composites is reported. This procedure involves initial glycolysis with diethylene glycol to produce a mixture (GPET) comprising oligomers of 2–7 terephthalate units followed by trans/esterification of GPET with fatty acid chains supplied by brown grease, an agricultural by‐product of animal fat of relatively low nutritional or fuel value. This process yields PGB comprising a mixture of mono‐terephthalate ester derivatives. The olefin units provided by unsaturated fatty acid chains in brown grease were crosslinked by an inverse vulcanization reaction with elemental sulfur to give composites GBSx(x = wt% S, varied from 80%–90%). The compressive strengths of GBS80(27.5 ± 2.6 MPa) and GBS90(19.2 ± 0.8 MPa) exceed the compressive strength required of ordinary Portland cement (17 MPa) for its use in residential building foundations. The current route represents a way to repurpose waste plastic, energy sector by‐product sulfur, and agricultural by‐product brown grease to give high strength composites with mechanical properties suggesting their possible use to replace less sustainably sourced legacy structural materials.
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Evaluation of Animal Fats and Vegetable Oils as Comonomers in Polymer Composite Synthesis: Effects of Plant/Animal Sources and Comonomer Composition on Composite Properties
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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- Award ID(s):
- 2203669
- PAR ID:
- 10463654
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Macromolecular Chemistry and Physics
- Volume:
- 224
- Issue:
- 22
- ISSN:
- 1022-1352
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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