Evaluation of the Ecotoxicity of New Polyurethane Composites on Target Organisms for Aquatic and Atmospheric Environments.

This study examined the potential toxic effects of newly synthesized biocomposite polyurethanes (PURs), incorporating functionalized cellulose fibers extracted from the Mediterranean shrub Spartium junceum L., on two biomonitor organisms: the freshwater crustacean Daphnia magna and the epiphytic lichen Pseudevernia furfuracea. PUR composites were produced using either aromatic (MDI) or aliphatic (TMDI) diisocyanates, with or without cellulose fibers, and characterized chemically and morphologically. Toxicity tests revealed that leachates from aliphatic PURs without cellulose fibers exhibited slight to moderate acute toxicity to D. magna, likely due to unreacted amines and amides, whereas cellulose addition mitigated this effect. In lichens, aliphatic PURs induced oxidative stress and pigment alterations, with organotin catalysts implicated in pigment reduction; cellulose-containing composites generally showed reduced ecotoxicological impacts. The findings suggest that incorporating cellulose fibers in PUR formulations can decrease environmental toxicity, highlighting the importance of ecotoxicological assessment in developing sustainable polymer composites.