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Stały URI dla kolekcjihttp://hdl.handle.net/11652/4411

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Filtry

20223

Ustawienia

Autorsearch.filters.applied.operator.equals: search.filters.author.Draczyński, Zbigniew

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Teraz wyświetlane 1 - 3 z 3
  • Pozycja
    Preliminary studies on the preparation and properties of chitosan nonwovens modified with acid vapors
    (Wydawnictwo Politechniki Łódzkiej, 2022) Sikorski, Dominik; Bauer, Marta; Frączyk, Justyna; Draczyński, Zbigniew
    The aim of the study was to develop methods for modifying chitosan nonwovens in the gas phase (application of acid vapors). Organic and inorganic acids were used in the research. The time of treating chitosan nonwovens with acid vapors ranged from 10 to 120 min. The conducted research has shown that it is possible to modify chitosan nonwovens with the use of acid vapors (organic and inorganic). It was found that the action of acid vapors does not have a destructive effect on chitosan fibers (SEM tests), which means that the developed method can be applied to various forms of chitosan materials, while the modification is carried out on the finished form. Microbiological tests were used to investigate the activity and growth of the microorganisms, which were related to the acids in the modified nonwovens. Only materials modified with acetic acid and hydrochloric acid were found to have bacteriostatic properties against S. aureus and E. coli (gramnegative and gram-positive bacteria). It was also found that chitosan formate significantly reduced the number of colonies of S. aureus.
  • Pozycja
    Synthesis of mix chitin esters
    (Wydawnictwo Politechniki Łódzkiej, 2022) Bednarowicz, Anna; Tarzyńska, Nina; Patlewicz, Marta; Draczyński, Zbigniew
    The aim of this study was the synthesis of chitin esters, which at a later stage could be used to produce antibacterial textiles. The esterification of chitin was carried out using butyric anhydride, succinic anhydride and methanesulfonic acid as a catalyst. The produced products were analysed by FTIR and NMR techniques and the dynamic apparent viscosity of the spinning solutions was examined. The products containing butyl and succinic anhydride in molar ratios 95/5 and 85/15 showed the best properties.
  • Pozycja
    Accelerated hydrolysis of PLA fibers at low temperature
    (Wydawnictwo Politechniki Łódzkiej, 2022) Tarbuk, Anita; Čorak, Ivana; Đorđević, Dragan; Draczyński, Zbigniew
    The polylactide (PLA) is the most common biodegradable material. However, its biodegradation requires hydrolysis of PLA to oligomers or monomers before microbes can act. Hydrolytic degradation of PLA depends on temperature, time and relative humidity. It takes months and years until complete biodegradation. If a catalyst is introduced, i.e. alkali or alcohol, it can be done in weeks. In this article, the alkaline hydrolysis was performed at low temperatures 40-60°C without and with the addition of cationic compound as an accelerator for the purpose of saving energy and time for complete PLA degradation. It has been shown that complete degradation can be achieved in only 10 min at 40°C.