20.500.12556/RUL-158695 Optimizacija pridobivanja nanofibrilirane celuloze iz lesne biomase magistrska naloga Optimization of producing nanofibrillated cellulose from woody biomass M. Sc. thesis Preučevali smo pogoje pridobivanja nanofibrilirane celuloze (NFC) iz bruševine podjetja Karton Količevo. Ugotovili smo, da je za izolacijo NFC nujno potrebna kemična obdelava izvorne surovine. Kemični postopki, ki smo jih uporabili, so bili ekstrakcija po Soxhletu, delignifikacija z reagentom NaClO, odstranjevanje hemiceluloz s KOH ali NaOH in oksidacija z reagentom TEMPO. Rezultati so pokazali, da je za doseganje večje čistote materiala bolje, če se postopek delignifikacije ponovi za postopkom odstranjevanja hemiceluloz. Hkrati se zmanjša tudi čas mehanskih postopkov za nastanek gelaste oblike NFC. Na čistoto ugodno vpliva tudi daljši čas delignifikacije. Opazili smo tudi vpliv oksidacije z reagentom TEMPO, saj ta skrajša čas, potreben za nastanek gelaste oblike. Rezultati FT-IR analize so potrdili, da so bili postopki odstranjevanja, lignina in hemiceluloz uspešni. Reološki testi so pokazali naraščanje elastičnega (G`) in viskoznega (G``) strižnega modula z večanjem frekvence obremenjevanja, kar pomeni, da se gelasta disperzija obnaša psevdoplastično. Parametre nastanka NFC smo poiskušali optimizirati z vidika količine porabljenih kemikalij pri kemični predelavi. Morfologija končnega produkta je nekoliko drugačna kot morfologija industrijske NFC, zato sklepamo, da je naš produkt nekoliko slabše kvalitete The production conditions of nanofibrillated cellulose (NFC) from wood pulp (Karton Količevo) were examined. We concluded that it is crucial to use chemical modification in the production of NFC. The chemical modification procedures used were: Soxhlet extraction, delignification using NaClO, removal of hemicelluloses using KOH or NaOH and TEMPO mediated oxidation. The results showed that higher purity could be achieved by repeating delignification process after the process of hemicellulose removal. The time needed for mechanical modification and formation of NFC gel was reduced by performing this process. Longer delignification process time favourably affects the purity of end product. The observed effect of TEMPO mediated oxidation was the reduction of the time needed for formation of NFC gel. The results of FT-IR confirmed that both delignification process and process of hemicellulose removal were successful. Rheological tests showed an increase in elastic (G`) and viscous (G``) shear modulus with increased frequency of stress, which means that gelatin dispersion behaves pseudoplastically. An effort towards optimization of amount of needed chemical materials was made as well. The morfology of the end product is somewhat different from that of industrially produced NFC, indicating lower quality of our product lesna biomasa nanofibrilirana celuloza optimizacija postopkov kemična modifikacija mehanska obdelava woody biomass nanofibrillated cellulose optimization of procesess chemical modification mechanical treatment true false false J. Bertoncelj Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-06-19 11:53:40 2024-06-19 11:53:42 2024-07-03 03:40:57 0000-00-00 00:00:00 2015 0 Ljubljana 2015 Ljubljana XIV, 91 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*813 2457737 MAG_Bertoncelj_Jani_2015.pdf MAG_Bertoncelj_Jani_2015.pdf 1 619074C4AD1815105469ED999B887C4E af21c2dd5da7c82376fba8181bc2e1c51b83baff906fb17079642cb5a711fd5e d03d02ce-2e21-11ef-aa1b-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=186407 Biotehniška fakulteta 0 0 0