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Author:Lahti, Jussi
Title:Grafting lauryl acrylate onto cellulose by the action of UV laser
Lauryyliakrylaatin oksastus selluloosaan UV-laserin avulla
Publication type:Master's thesis
Publication year:2011
Pages:68 + [5]      Language:   eng
Department/School:Puunjalostustekniikan laitos
Main subject:Puunjalostuksen kemia   (Puu-19)
Supervisor:Vuorinen, Tapani
Instructor:Kontturi, Eero
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
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Location:P1 Ark Aalto  2249   | Archive
Keywords:cellulose
UV laser
grafting
lauryl acrylate
selluloosa
UV-laser
oksastus
lauryyliakrylaatti
Abstract (eng): A novel method, which would enable the production of accurate hydrophobic pattern onto the surface of cellulose substrate, was developed.
The method is based on the grafting of highly hydrophobic lauryl acrylate (LA) onto the cellulose by the action of ultraviolet (UV) laser.

At first, the effect of 244 nm UV laser radiation on cellulose in the presence of air and nitrogen was studied.
UV resonance Raman (UVRR) spectroscopic measurements of the irradiated samples showed that cellulose degraded through photo oxidation under air whereas photo- and thermal degradation through dehydration occurred under nitrogen.
Intensity ratio of the bands at 1098 and 1639 cm-1 (I1098/I1639) calculated from the UVRR spectra revealed that cellulose degraded linearly as a function of time when 1 mW UV laser was used.
In the case of 5 mW and 10 mW UV laser, most of the degradation of cellulose occurred at the initial stage of the irradiation.
The degradation became stronger and faster with increasing laser power.

The developed UV grafting method includes three main steps: pipetting of LA /acetone solution onto Whatman paper, irradiation of the sample with the 244 nm UV laser, and washing of the sample with acetone and methyl isobutyl ketone (MIBK).
Two washing sequences were tested at the final step.
The first washing sequence included dissolution in MIBK alone whereas the second washing sequence included also mechanical treatment in ultrasonic bath.

X-ray photoelectron spectroscopic (XPS) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic measurements of the prepared samples showed that LA had reacted on the surface of cellulose due to UV laser irradiation.
Homopolymerization of LA and grafting of LA onto cellulose were the possible reactions.
However, it was not possible to prove that LA grafting onto cellulose had actually happened.
Minor dehydration of cellulose may have also occurred.
When the LA concentration was high, LA homopolymer layer was formed onto the surface of cellulose due to UV laser irradiation.
The second washing sequence was much more efficient in removing this layer than the first washing sequence.
Abstract (fin): Diplomityössä alettiin kehittää uutta menetelmää, jonka avulla voitaisiin valmistaa tarkkoja hydrofobisia kuvioita selluloosapinnalle.
Menetelmä perustuu erittäin hydrofobisen lauryyliakrylaatin (LA) oksastukseen selluloosaan ultraviolettilaserin (UV) avulla.

Aluksi tutkittiin 244 nm:n UV-lasersäteilyn vaikutusta selluloosaan ilmassa ja typessä.
Säteilytettyjen näytteiden UV-resonanssi-Raman-spektroskopiset (UVRR) mittaukset osoittivat, että selluloosa hajosi valohapettumisen kautta ilmassa.
Typessä selluloosa puolestaan valo- ja lämpöhajosi dehydraation kautta.
UVRR-spektrien kohdissa 1098 cm-1 ja 1639 cm-1 sijaitsevista juovista lasketut intensiteettisuhteet (I1098/I1639) osoittivat, että 1 mW:n UV-lasersäteilyn seurauksena selluloosa hajosi lineaarisesti ajan funktiona.
Suurin osa selluloosan hajoamisesta tapahtui säteilytyksen alkuvaiheessa, kun 5 mW:n ja 10 mW:n säteilytehoa käytettiin.
Selluloosan hajoaminen voimistui ja nopeutui lasertehon kasvaessa.

Kehitetty UV-oksastusmenetelmä sisältää kolme vaihetta: LA/asetoniliuoksen pipetointi Whatman-paperille, näytteen säteilytys 244 nm:n UV-laserilla ja näytteen pesu asetonilla sekä metyyli-isobutyyliketonilla (MIBK).
Kahta pesusarjaa kokeiltiin viimeisessä vaiheessa.
Ensimmäinen pesusarja sisälsi pelkästään liuotuksen MIBK:lla, kun taas toinen pesusarja sisälsi myös mekaanisen käsittelyn ultraäänihauteessa.

Valmistettujen näytteiden röntgenelektronispektroskopia (XPS) ja vaimennettu kokonaisheijastus-Fourier-muunnosinfrapunaspektroskopia (ATR-FTIR) osoittivat, että LA oli reagoinut selluloosan pinnalla UV-lasersäteilytyksen vaikutuksesta.
Mahdolliset reaktiot olivat LA:n homopolymeraatio ja LA:n oksastus selluloosaan.
Saatujen tulosten perusteella ei voitu kuitenkaan todistaa, että LA:n oksastus selluloosaan oli todella tapahtunut.
Vähäistä selluloosan dehydraatiota saattoi myös tapahtua.
Kun LA:n konsentraatio oli suuri, LA-homopolymeerikerros muodostui selluloosan pinnalle UV-lasersäteilytyksen vaikutuksesta.
Toinen pesusarja oli paljon tehokkaampi tämän kerroksen poistossa kuin ensimmäinen pesusarja.
ED:2011-02-16
INSSI record number: 41529
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