Thin polyethylene (LDPE) films with controlled crystalline morphology for studying plastic weathering and microplastic generation

• Published in: Polymer degradation and stability Vol. 195; p. 109791
• Main Authors: Julienne, Fanon, Lagarde, Fabienne, Bardeau, Jean-François, Delorme, Nicolas
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.01.2022; Elsevier BV; Elsevier
• Subjects: Accelerated tests; Aging; Chemical Physics; Crack initiation; Cracks; Crystal structure; Crystallinity; Crystallization; Dip coatings; Dip-coating; Engineering Sciences; Fragmentation; General Physics; Immersion coating; Low density polyethylenes; Materials; Microplastic; Morphology; Oxidation; Photodegradation; Physics; Plastics; Polyethylene; Polyethylene films; Polymer films; Polymers; Spherulites; Thick films; Thickness; Thin films; Weathering; Polyethylene; Dip-coating; Aging; Weathering; Polymer films; Microplastic; Fragmentation; Polyéthylène; Revêtement par trempage; Érosion; Microplastique; Films polymères; Vieillissement
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2021.109791

•LDPE films with controlled crystalline morphology were successfully prepared by dip coating method.•Accelerate weathering experiment were performed to study the influence of the spherulite dimension on the aging process.•An increase of the erosion process for films presenting the largest spherulites dimension is observed.•Crack initiation is favored for the film presenting the largest spherulites dimension.•Erosion and crack propagation were found to be independent of the measured carbonyl index. Plastic pollution has become one of the most visible environmental issue. Studying the aging and the fragmentation mechanism of polymers therefore raises environmental and health issues. Since it is particularly difficult to monitor all these processes in the real environment, laboratory studies are still necessary to obtain more accurate data and to identify the pathways leading to the outcome of plastic debris in the environment. In this paper we present a new method to prepare micrometer thick LDPE films with different thicknesses and controlled crystalline morphologies (i.e. spherulite size) using dip-coating process. LDPE films presenting different spherulite dimensions were submitted to an accelerated weathering test which indicates that spherulite size has only a weak influence on the rate of photo-oxidation. However, films presenting large spherulites morphologies seem to be more sensitive to surface erosion and crack initiation. We believe that the method developed in this paper can be used to study with more control and more rapidly (i.e. thin film and accelerated weathering) the influence of crystalline morphology on a wide range of semi-crystalline polymers in different aging conditions and thus help to better understand the fragment production of plastics in the environment.