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Abstract Poly(methyl methacrylate) (PMMA) is an important commodity polymer having a wide range of applications. Currently, only about 10% of PMMA is recycled. Herein, a simple two‐stage process for the chemical upcycling of PMMA is discussed. In this method PMMA is modified by transesterification with a bio‐derived, olefin‐bearing terpenoid, geraniol. In the second stage, olefin‐derivatized PMMA is reacted with sulfur to form a network composite by an inverse vulcanization mechanism. Inverse vulcanization of PGMA with elemental sulfur (90 wt.%) yielded the durable compositePGMA‐S. This composite was characterized by NMR spectrometry, IR spectroscopy, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry. Composite water uptake, compressional strength analysis, flexural strength analysis, tensile strength analysis, and thermal recyclability are presented with comparison to current commercial structural materials.PGMA‐Sexhibits a similar compressive strength (17.5 MPa) to that of Portland cement.PGMA‐Sdemonstrates an impressive flexural strength of 4.76 MPa which exceeds the flexural strength (>3 MPa) of many commercial ordinary Portland cements. This study provides a way to upcycle waste PMMA through combination with a naturally‐occurring olefin and industrial waste sulfur to yield composites having mechanical properties competitive with ecologically detrimental legacy building materials.
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Single‐stage chemical recycling of plastic waste to yield durable composites via a tandem transesterification‐thiocracking process
Abstract Environmental contamination by plastic waste is a growing threat to the environment and human health. Unfortunately, most post‐consumer plastics are still disposed of in landfills, even plastics that could be easily recycled via simple chemical processes. This disconnect between technology and implementation is partly due to the economic barrier posed by multi‐step processes that convert plastic waste into commodity goods. There is an urgent need for green methods to convert plastic waste directly into marketable commodities via simple processes. Herein we report a simple, single‐stage process to chemically recycle poly(ethylene terephthalate) (PET) to yield composites having thermal and mechanical properties that are competitive with commercial structural materials like Portland cement. In this protocol, a mixture of PET and geraniol are heated with elemental sulfur. In this process, transesterification between geraniol and PET with concomitant thiocracking of the PET backbone leads to the formation of a highly‐crosslinked sulfur–PET–geraniol (SPG) network composite. The composite exhibited compressive strength (23.1 MPa) greater than that required for Portland cement to be used in building foundations. This new, single‐stage chemical recycling strategy thus employs a bio‐olefin and waste sulfur to convert PET waste into a durable composite that could serve as a sustainable alternative to traditional cements.
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- Award ID(s):
- 2203669
- PAR ID:
- 10410496
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 61
- Issue:
- 9
- ISSN:
- 2642-4150
- Page Range / eLocation ID:
- p. 787-793
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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