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Background. In recent years disposable 'biodegradable bags' have substituted a large number of conventional polymer bags. Most commercially available bags are made of cheap thermoplastic materials (polyethylene, polypropylene), which have good mechanical properties, but are non-biodegradable. In order to improve the biodegradability of bags synthetic polymers are usually mixed with natural polymers, such as starch or pro-oxidants. However, the essential question whether biodegradable bags are really eco-friendly and can be decomposed by microorganisms in the environment has not been answered yet. The aim of the study was to determine the biodegradability of commercially available disposable bags. Material and methods. Three different plastic bags (polyethylene, polyethylene oxy-biodegradable, polyethylene biodegradable with addition of starch) and one paper bag were used in the study. Biodegradation of the bags was studied for 12 months in the soil environment (both with or without addition of the microbial agent). The efficiency of material biodegradation was assessed periodically using three different methods: CO2 evolution test, mechanical properties analysis and biofilm formation analysis. Results. The results suggest that only paper bags are completely biodegradable in the soil environment, as could be seen by their high mineralisation, deterioration of mechanical properties and formation of a bacterial biofilm on cellulose fibres. Polyethylene bags with the addition of starch were biodegradable, but to a lesser extent. Other bags were resistant to microbial degradation in soil. The addition of the microbial agent did not influence biodegradability of the bags under study. Conclusions. The so-called 'biodegradable' plastic bags under study could not be bioavailable to autochthonous microorganisms inhabiting soil. Although they are described as 'biodegradable' on their labels, they may not be as eco-friendly as their manufacturers declare. Therefore, it is important to develop new, biodegradable polymer materials that can be used for production of commercially available bags. [ABSTRACT FROM AUTHOR]

In the framework of this study a synthesis methodology and characterization of long alkyl herbicidal ionic liquids (HILs) based on four commonly used herbicides (2,4-D, MCPA, MCPP, and dicamba) are presented. New HILs were obtained with high efficiency (>95%) using an acid-base reaction between herbicidal acids and hexadecyltrimethylammonium, octadecyltrimethylammonium, and behenyltrimethylammonium hydroxides in alcoholic medium. Among all synthesized salts, only three compounds comprising the MCPP anion were liquids at room temperature. Subsequently, the influence of both the alkyl chain length and the anion structure on their physicochemical properties (thermal decomposition profiles, solubility in 10 representative solvents, surface activity, density, viscosity, and refractive index) was determined. All HILs exhibited high thermal stability as well as surface activity; however, their solubility notably depended on both the length of the carbon chain and the structure of the anion. The herbicidal efficacy of the obtained salts was tested in greenhouse and field experiments. Greenhouse testing performed on common lambsquarters (Chenopodium album L.) and flixweed (Descurainia sophia L.) as test plants indicated that HILs were characterized by similar or higher efficacy compared to commercial herbicides. The results of field trials confirmed the high activity of HILs, particularly those containing phenoxyacids as anions (MCPA, 2,4-D, and MCPP).