Resistance of polylactic acid/nanofibrillated cellulose composite to scratching

The aim of the study was to prepare a bionanocomposite based on polylactic acid (PLA) with the addition of nanofibrillated cellulose (NFC) as a reinforcement component. For the production of the composite we used unmodified and acetylated NFC (A_NFC). Freeze-dried NFC was acetylated in a heterogeneous system with acetic anhydride in dimethylformamide (DMF) in the presence of pyridine as a catalyst. The success of the acetylation was determined by FT-IR spectroscopy. PLA films were prepared with the addition of 2.5%, 5% and 10% of unmodified and acetylated NFC. The focus of this research was the impact of the NFC additive on the transparency and on the resistance of the bionanocomposite to scratching. The transparency of the bionanocomposite film was measured using UV-Vis spectrophotometry, and the resistance of the films to scratching was evaluated with a scratch test. The optimal amount of NFC and A_NFC added to the polymer PLA to achieve better resistance of the bionanocomposite to scratching was determined. The best resistance of the prepared bionanocomposite to scratching was achieved by the addition of a 2.5% A_NFC to the PLA polymer, which also has minimal reduced transparency with respect to the PLA film. With the highest addition of A_NFC to the PLA polymer, bionanocomposite films with minimal reduction of transparency were obtained

Resistance of polylactic acid/nanofibrillated cellulose composite to scratching

Cilj študije je bil priprava bionanokompozita na osnovi polimlečne kisline (PLA) z dodatkom nanofibrilirane celuloze (NFC) kot ojačitvene komponente. Za izdelavo kompozita smo uporabili nemodificirano in acetilirano NFC (A_NFC). NFC, posušeno z zamrzovanjem, smo acetilirali v heterogenem sistemu z acetanhidridom v dimetilformamidu (DMF) ob prisotnosti piridina kot katalizatorja. Uspešnost acetiliranja smo ugotavljali z infrardečo (FT-IR) spektroskopijo. Pripravili smo PLA filme z 2,5 %, 5 % in 10 % dodatkom nemodificirane oziroma acetilirane NFC. Osredotočili smo se na proučevanje vpliva dodatka NFC na prosojnost bionanokompozita in na njegovo odpornost proti razenju. Prosojnost bionanokompozitnega filma smo merili z UV-Vis spektrofotometrijo, odpornost površine filmov proti razenju pa smo ovrednotili z vzmetnim svinčnikom. Določili smo optimalno količino dodane NFC in A_NFC polimeru PLA za doseganje boljše odpornosti proti razenju. Ugotovili smo, da z dodatkom 2,5 % A_NFC dosežemo najboljšo odpornost pripravljenega bionanokompozita proti razenju, ki ima tudi minimalno zmanjšano prosojnost glede na PLA film. Celo z najvišjim dodatkom A_NFC k PLA polimeru smo dobili bionanokompozitne folije z minimalnim zmanjšanjem prosojnostiThe aim of the study was to prepare a bionanocomposite based on polylactic acid (PLA) with the addition of nanofibrillated cellulose (NFC) as a reinforcement component. For the production of the composite we used unmodified and acetylated NFC (A_NFC). Freeze-dried NFC was acetylated in a heterogeneous system with acetic anhydride in dimethylformamide (DMF) in the presence of pyridine as a catalyst. The success of the acetylation was determined by FT-IR spectroscopy. PLA films were prepared with the addition of 2.5%, 5% and 10% of unmodified and acetylated NFC. The focus of this research was the impact of the NFC additive on the transparency and on the resistance of the bionanocomposite to scratching. The transparency of the bionanocomposite film was measured using UV-Vis spectrophotometry, and the resistance of the films to scratching was evaluated with a scratch test. The optimal amount of NFC and A_NFC added to the polymer PLA to achieve better resistance of the bionanocomposite to scratching was determined. The best resistance of the prepared bionanocomposite to scratching was achieved by the addition of a 2.5% A_NFC to the PLA polymer, which also has minimal reduced transparency with respect to the PLA film. With the highest addition of A_NFC to the PLA polymer, bionanocomposite films with minimal reduction of transparency were obtained

Zaključna razstava študentk 4. letnika likovne pedagogike : Predmeta Risanje in Slikanje, mentor Zdenko Huzjan

Vabljeni na ogled Zaključne razstave študentk 4. letnika Likovne pedagogike Mentor: Prof. Zdenko Huzjan RAZSTAVLJAJO: Tamara Bregar Monika Feuče Veronika Gnidovec Tea Hegeduš Petra Javornik Katarina Juvan Ana Kavčnik Hana Kropivšek Julija Leben Živa Lencl Lara Loboda Tina Nagode Barbara Osolnik Mojca Pirih Nika Rosman Urša Zalar Darja Zupan Razstava bo na ogled od 11. 6. do 29.6.2015, od pon. do pet. med 8. in 18. uro, v sob. med 8. in 14. uro