Exploring heterogeneity in the properties of monolayer LDPE greenhouse films under natural ageing

This study investigates the dynamic interplay between chemical structural changes and mechanical alterations in stabilized and unstabilized LDPE films during the photodegradation process. By employing RAMAN spectroscopy and Depth Sensing Indentation (DSI) experiments, we delve into the depth profile of these transformations, shedding light on the heterogeneous nature of LDPE degradation. Our findings underscore the pivotal role of surface degradation, where oxygen diffusion and UV light attenuation trigger spatially varying degradation patterns, with degradation initiating at the exposed surface and diminishing in intensity towards the film's core. Notably, chemical reactions, particularly chain scission reactions, predominantly manifest on the film surfaces, indicative of potential secondary crystallization. Nanoindentation results further corroborate these observations, revealing a nuanced interplay between crystallinity distribution and mechanical properties across the film's thickness. By elucidating the depth profile of chemical and mechanical degradation, our study advances the understanding of LDPE photodegradation, offering valuable insights for optimizing LDPE films' performance and durability in real- world applications.

Audience Take Away Notes:

• Understanding the spatial distribution of chemical and mechanical changes in LDPE films during photoageing: The presentation will elucidate how photodegradation affects the LDPE film's surface and how these changes propagate through its thickness. This knowledge will provide insights into the spatial patterns of degradation within the material
• Application of Raman spectroscopy and depth sensing indentation (DSI) techniques: Attendees will gain knowledge about the practical application of advanced analyticaltechniques such as Raman spectroscopy and DSI for characterizing the chemical and mechanical properties of polymers. They will learn how these techniques can be employed to study the depth profile of degradation in LDPE films
• Potential for interdisciplinary research and teaching: The research findings presented can serve as a valuable resource for other faculty members interested in interdisciplinary research or teaching. The study integrates aspects of materials science, spectroscopy, and mechanical testing, offering opportunities for collaboration and curriculum development across disciplines
• Practical solutions for polymer design and engineering: The presentation will highlight how the insights gained from this research can contribute to the development of practical solutions for polymer design and engineering. By understanding the spatial distribution of degradation in LDPE films, designers and engineers can optimize material selection, enhance product performance, and extend product lifespan in outdoor applications