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Author:Määttänen, Mikko Hermanni
Title:Selluloosan nanokiteiden valmistus kaasumaisella suolahapolla ja nanokiteiden hydrofobointi
Using gas-phase hydrochloric acid to produce CNCs of commercial hardwood pulp and hydrophobizing of CNCs
Publication type:Master's thesis
Publication year:2011
Pages:88 + [16]      Language:   fin
Department/School:Puunjalostustekniikan laitos
Main subject:Puunjalostuksen kemia   (Puu-19)
Supervisor:Laine, Janne
Instructor:Kontturi, Eero ; Meriluoto, Anne
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
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Location:P1 Ark Aalto  2227   | Archive
Keywords:cellulose
hydrolysis
gas-phase hydrogen chloride
hydrochloric acid
leveling off degree of polymerization
cellulose nanocrystals
selluloosa
hydrolyysi
selluloosan depolymeroituminen
kaasumainen vetykloridi
suolahappo
selluloosan nanokide
Abstract (eng): The aim of the study was to try to hydrolyse cellulose from various sources with gas-phase hydrogen chloride (HCl) and to manufacture cellulose nanocrystals (CNC).
This novel method has been proved to yield CNCs with cotton based filter paper which primarily consists of cellulose.
The cellulose samples were hydrolysed at their levelling off degree of polymerisation (LODP) -level which is a unique feature for each cellulose source.
The viscosity of the cellulose sample is formed by the remaining cellulose nanocrystals and it is determined by viscometer.
The cellulose samples consist of, besides cellulose, also hemicellulose and residual lignin.
In addition, two of the samples had been oxidized by TEMPO-treatment and one sample was partly carboxymethylated.
The purpose of these samples was to study how the hydrolysis proceeds with modified cellulose.

The mass of the cellulose samples decreases as water soluble carbohydrates are formed during the sample's degradation and as the samples are rinsed and flushed with water.
With filter paper, the mass loss is about 1 % of the total weight as it is with the birch pulp 20% when m-35% HCl is used.
The rather small weight loss of the filter paper is due to the hydrolysed amorphous parts of the cellulose and xylan while with the birch sample it is mainly due to degradation of xylan.
The hemicellulose content of the birch sample in the study is about 23% which corresponds well with the weight loss.
The birch pulp CNCs were studied with AFM.

The other aim of this study was to chemically modify CNCs of filter paper and birch pulp samples.
The samples were hydrofobized by esterifying an acetic acid onto to the crystallite structures.
Abstract (fin): Työn tavoitteena oli hydrolysoida erilaisia selluloosanäytteitä niiden LODP-tasolle kaasumaisella vetykloridilla, joka muodostaa näytteen veden kanssa suolahappoa.
Menetelmän toimivuutta testattiin mittaamalla sellunäytteestä ja liuottimesta muodostuvan liuoksen viskositeettia.
Menetelmän on todettu hydrolysoivan puuvillaperäisen suodatinpaperin sille ominaiselle LODP-tasolle, joka muodostuu hydrolyysissa jäljelle jäävistä selluloosan nanokiteistä (CNC).
Kokeellisessa osassa näytteiden ja liuottimen muodostaman liuoksen viskositeettia seurattiin hydrolyysin aikana useissa suolahappokonsentraatioissa.
Näytteet hydrolysoitiin niille ominaiselle LODP-tasolle ja jäljelle jääneitä selluloosan nanokiteitä kuvattiin atomivoima-mikroskoopilla.

Happohydrolyysin aikana näytteen massa laskee, kun vesiliukoisia hiilihydraatteja muodostuu ja poistuu näytteestä vesihuuhtelun jälkeen.
Käytettäessä 35 % -suolahapon muodostamaa kaasuilmakehää, suodatinpaperin massahäviö on 24h hydrolyysin ja sitä seuraavan huuhtelun jälkeen alle 1 % kun se koivusellulla on noin 20 %.
Suodatinpaperin melko vähäinen painonmuutos johtuu amorfisten alueiden hajoamisesta, kun se koivusellulla muodostuu pääosin hydrolysoituneesta ksylaanista sekä vähäisissä määrin selluloosan amorfisten alueiden hydrolyysista.

Työn toisena tavoitteena oli kemiallisesti muokata LODP-tasolleen hydrolysoituja suodatinpaperi- ja koivusellunäytteitä.
Näytteiden sisältämien nanokiteiden rakenteeseen yritettiin esteröidä etikkahappoa soveltamalla bakteeriperäiselle selluloosalle tehtyä vastaavaa käsittelyä.
ED:2012-09-06
INSSI record number: 45219
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