Hoseini, M., Stead, J. and Bond, T. orcid.org/0000-0002-5546-0210 (2023) Ranking the accelerated weathering of plastic polymers. Environmental Science: Processes & Impacts, 25 (12). pp. 2081-2091. ISSN 2050-7887
Abstract
The timespans over which different plastics degrade in the environment are poorly understood. This study aimed to rank the degradation speed of five widespread plastic polymers–low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polylactic acid (PLA) and polyethylene terephthalate (PET)–in terms of their physicochemical properties. Five of the six samples were plastic films with identical dimensions, which allowed the influence of morphology to be excluded, with a polyethylene carrier bag (PEB) tested for comparison. An accelerated weathering chamber was used to photochemically degrade samples over 41 days, with degradation monitored via mass loss and changes to carbonyl index, crystallinity and contact angle. The mass loss ranking was PP ≫ LDPE > PEB > PS > PLA > PET. Estimates of the time needed for complete degradation ranged from 0.27 years for PP to 1179 years for PET. Therefore, mass loss in PP proceeded more rapidly than the other polymers, which was unexpected based on previous literature and is plausibly explained by the presence of an unlisted additive which accelerated degradation. Increases in carbonyl index proceeded more rapidly in PP and LDPE than the other polymers tested. However, changes in contact angle and crystallinity did not correspond to the mass loss ranking. Therefore, monitoring the carbonyl index during accelerated weathering trials can indicate which polymers will fragment more quickly. However, alternative approaches are needed to simulate conditions where photooxidation reactions are negligible, such as the ocean floor.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2023 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Chemical and Biological Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 30 Oct 2023 15:52 |
Last Modified: | 25 Oct 2024 15:14 |
Status: | Published |
Publisher: | Royal Society of Chemistry (RSC) |
Refereed: | Yes |
Identification Number: | 10.1039/d3em00295k |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:204721 |