diplomsko delo
Tjaša Šmidovnik (Author), Primož Oven (Reviewer), Ida Poljanšek (Mentor), Viljem Vek (Co-mentor)

Abstract

Cilj diplomske naloge je bila priprava kompozita na osnovi polimlečne kisline, nanofibrilirane celuloze ter ekstrakta lesa rdečega bora (Pinus sylvestris L.). Najprej smo naredili Soxhletovo ekstrakcijo z različnimi topili (cikloheksan, aceton, etanol), ter tako pridobili moker ekstrakt, katerega smo nato rotavapirali, da smo dobili suhi ekstrakt grče rdečega bora. Naredili smo kemijsko analizo ekstraktov (z gravimetrično metodo, s tekočinsko kromatografijo visoke ločjivosti (HPLC) ter z UV – Vis spektrofotometrijo). Posušeno nanofibriliranocelulozo, pridobljeno s sušenjem z zmrzovanjem, smo zmešali s kloroformom ter homogenizirali. Na koncu smo pripravili 10 % raztopino polimlečne kisline. Komponente smo mešali v različnih razmerjihin s tem dobili želene kompozite. Po 40 dneh smo naredili test odpornosti proti razenju. Rezultati mehanskih lastnosti filmov pokažejo, da dodatek nanofibrilirane celuloze poslabša mehanske lastnosti osnovnega polimera PLA. Ekstrakt lesa bora v kombinaciji z nanofibrilirano celulozo v določenih primerih izboljša lastnosti filma, v določenih primerih pa ne pripomore k boljši odpornosti proti razenju. Najboljšo odpornost proti razenju je imel kompozit, narejen iz PLA z dodatkom ekstrakta, najslabšo pa kompozit narejen iz PLA z dodatkom 2 % posušene nanofibrilitane celuloze obdelane z reagentom TEMPO in ekstrakta, kateri je bil zelo krhek.

Keywords

nanofibrilirana celuloza;polimlečna kislina;ekstrakt bora;kompozit;HPLC;UV-Vis;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [T. Šmidovnik]
UDC: 630*813.2
COBISS: 2814601 Link will open in a new window
Views: 870
Downloads: 365
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Other data

Secondary language: English
Secondary title: Composite based on nanofibrillated cellulose, polylactic acid and extractives of Pinus sylvestris
Secondary abstract: The aim of this thesis was to prepare a polylactic acid, nanofibrillated cellulose and Pinus sylvestris extract based composite. First, we performed the Soxhlet extraction with different solvents (cyclohexane, acetone, ethanol) to obtain a wet extract, which we then rotavaped to produce a dry extract of Scots pine knot wood. We performed chemical analysis of extract (gravimetric method, high performance liquid chromatography (HPLC), UV – Vis spectrophotometry). We then lyophilised the nanofibrillated cellulose, mixed it with chloroform and homogenized the mixture. Lastly, we prepared the polylactic acid. We mixed the components to obtain the desired composites. We performed a scratch test after 40 days. We expected the nanofibrillated cellulose to improve the mechanical properties and the extractives to impair them, which has not proved to be entirely correct. The addition of nanofibrillated cellulose worsened the mechanical properties oh the PLA polymer. Extract combined with nanofibrillated cellulose improved the properties of film in some cases, while it did not produce a better resilience against scratching in others. The most resilient was the PLA and extract based composite, while the one made of PLA, extract and 2 % freeze dried nanofibrillated cellulose proved to be the least resilient.
Secondary keywords: nanofibrillated cellulose;polylactic acid;extract of Pinus sylvestris;composite;HPLC;UV-ViS;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za lesarstvo
Pages: XI, 39 f., [4] f. pril.
ID: 10910359