Doctoral defence: Alina Ismagilova "Safety assessment of novel biobased polymers and compounds used in low carbon technologies"

On 4 September at 13:15 Alina Ismagilova will defend her doctoral thesis "Safety assessment of novel biobased polymers and compounds used in low carbon technologies" for obtaining the degree of Doctor of Philosophy (Environmental Engineering)

Supervisiors:
Associate Professor Lauri Vares, University of Tartu
Associate Professor Veljo Kisand, University of Tartu

Opponent:
Associate Professor Anita Jemec Kokalj, University of Ljubljana, Slovenia

Summary:
The worldwide rise in material and chemical usage—especially plastics—has raised significant concern over their long-term effects on the environment and human health. As a result, there is a growing interest in sustainable alternatives, leading to the development of innovative bio-based monomers and polymers from renewable resources. Although these options are intended to reduce reliance on fossil-derived plastics, their safety is not assured; some bio-based monomers, polymers, or their degradation products may still be toxic. This underscores the need for a thorough environmental evaluation of such alternatives.

This thesis investigates the environmental risks associated with bio-based materials, including isosorbide-based acrylates and methacrylates, PLA-derived acrylates, lignin-based methacrylates, and amines used in CO₂ capture and “switchable water” solvent systems. A series of aquatic ecotoxicological assays using bacteria (Alivibrio fischeri, Escherichia coli), vascular plants (Spirodela polyrhiza), and invertebrates (Thamnocephalus platyurus, Daphnia magna) revealed that some monomers, especially acrylates, exhibited moderate to high toxicity, while their corresponding polymers were mainly non-toxic. Cytotoxicity testing on human HeLa cells further indicated a significant reduction in toxicity upon polymerization. Ecotoxicological evaluation of amines used in CO₂ capturing technologies revealed that these compounds are relatively safe towards aqueous life, except for the more hydrophobic diamines, which should be carefully considered. Furthermore, biofilm analysis on various materials showed that bacterial colonization patterns depend on the type of material, with conventional plastics and coated paperboard supporting distinct microbial communities. These biofilms include taxa with known biodegradability, highlighting their ecological significance.

Overall, these findings emphasize that the chemical toxicity and microbial interactions of new bio-based materials need to be carefully assessed prior to their wider use. This comprehensive evaluation is essential to ensure that such materials not only lower carbon emissions but also safeguard environmental and human health.