Struktura i svojstva celuloze

undergraduate thesis

• Title (english): Structure and properties of cellulose
• Author: Ivana Jazbišek
• Mentor: Mirela Leskovac (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Committee member: Emi Govorčin Bajsić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Celuloza je jedan od najbrojnijih ugljikovih spojeva koji se nalaze u prirodi. Nastaje biosintezom radi čega se svrstava u prirodne polimere. Celuloza je biokompatibilan i obnovljiv polimer stoga se smatra alternativom nerazgradivim polimerima na bazi fosilnih goriva. Celuloza se kao prirodni polimer koristi za različite primjene od adheziva, kozmetike pa sve do lijekova. U ovom radu dan je pregled dosadašnjih spoznaja o strukturi i svojstvima celuloze. Istražena su svojstva nekoliko različitih celuloznih materijala: celugel, celofan, hidroksipropil celulozu (HPC), natrij-karboksimetil celuloza (Na-CMC) i pamuk. Strukturna analiza provedena je primjenom FTIR-ATR spektroskopije, a toplinska svojstva određena su primjenom termogravimetrijske analize i diferencijalne pretražne kalorimetrije (DSC). FTIR analizom utvrđena je celulozna struktura i visoka hidrofilnost uzoraka HPC, celugela, Na-CMC i pamuka na osnovi vibracija koje se pripisuju adsorbiranoj vodi. Odsutnost navedenih vrpci kod celofana ukazuje na njegovu hidrofobnu površinu. Termogravimetrijskom analizom utvrđena je najmanja toplinska stabilnost celugela i visoka stabilnost celofana. Bolja toplinska stabilnost celofana rezultat je modifikacije površine celofana odgovarajućim polimerom. Visoki udio ostatka nakon razgradnje kod HPC i celugel uzoraka ukazuje na prisutnost anorganske komponente. DSC analiza pokazala je znatne razlike u strukturi istraživanih celuloznih materijala. Kod uzoraka celugela, HPC, Na-CMC i pamuka potvrđena je visoka hidrofilnost površine koja je posljedica specifične strukture celuloze. U uzorku celofana utvrđena je dodatna komponenta kojom je celofan tretiran, a prema podatcima vjerojatno se radi o polipropilenu.

Abstract (english)

Cellulose is one of the most common carbon compounds in nature. It is generated by biosynthesis and classified into natural polymer. Regarding to biocompatibility and renewability, it is considered as an alternative to nonbiodegradable polymer based on the fossil fuels. As the natural polymer it has a variety of usage fields such as adhesive, cosmetics, drugs etc. This paper contains review of previous acknowledges about structure and composition of cellulose. Therefore, it contains an analysis of a few different materials: cellugel, cellophane, hydroxypropyl cellulose (HPC), sodium carboxymethyl cellulose (Na-CMC) and cotton. Structure analysis has been performed through FTIR-ATR spectroscopy and thermal properties have been investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). FTIR analysis established the structure of cellulose and high hydrophilicity of HPC, cellugel, sodium carboxymethyl cellulose (Na-CMC) and cotton samples based on adsorbed water vibrations. The lack of bands corresponding to adsorbed water in cellophane sample indicates a hydrophobic surface. Thermogravimetric analysis (TGA) determined the smallest thermal stability of cellugel and high stability of cellophane. Improvement in thermal stability of cellophane is the result of modification of cellophane surface with suitable polymer. High level of residue after the thermal degradation in HPC and cellugel correspond to presence of inorganic components. DSC analysis showed the substantial differences in the structure of observed cellulose materials. In cellugel, HPC and Na-CMC samples a high level of hydrophilicity surface was determined regarding to the specific structure. In the cellophane sample, an additional component by which cellophane was treated is found, most probably polypropylene.

• Keywords: celuloza; celugel; celofan; hidroksipropil celulozu (HPC); natrij-karboksimetil celuloza (Na-CMC); pamuk; FTIR; TGA; DSC
• Keywords (english): cellulose; cellugel; cellophane; hydroxypropyl cellulose (HPC); sodium carboxymethyl cellulose (Na-CMC); cotton; FTIR; TGA; DSC
• Language: croatian
• URN:NBN: urn:nbn:hr:149:493360
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-05-23 13:08:45