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Funkcionalizacija viskoze s hitozanom v kombinaciji z 1,2,3,4 butantetrakarboksilno kislino (BTCA)
Jasna Tompa, 2011, master's thesis

Abstract: Viskozna vlakna spadajo v skupino regeneriranih celuloznih vlaken in predstavljajo zanimiv nosilni substrat za potrebe proti-mikrobnih obdelav. Ena izmed najbolj obetajočih proti-mikrobno delujočih spojin sodobnega časa je hitozan. V tej raziskavi smo viskozo za dosego njene proti-mikrobne učinkovitosti obdelali z hitozanom v kombinaciji z 1,2,3,4 butantetrakarboksilno kislino BTCA, ki predstavlja dober nadomestek za formaldehidne reagente, namenjene obdelavi za izboljšanje mečkavosti materialov iz celuloze. Poudarek raziskovalnega dela je bil usmerjen tudi v izvor temperature obdelave, saj smo predpostavili, da bi sušenje s pomočjo mikrovalov lahko ugodno vplivalo na bolj učinkovito zamreženje viskoze. Učinkovitost zamreženja viskoze smo ovrednotili z različnimi analiznimi metodami. S FT-IR spektroskopijo smo potrdili nastanek estrnih povezav med hidroksilnimi skupinami viskoze in karboksilnimi skupinami BTCA. Učinkovitost zamreženja se odraža tudi na spremembi mehanskih lastnosti, zato smo z merjenjem kota poravnave ter pretržne sile in raztezka proučili morebitno poslabšanje mehanskih lastnosti viskoze po zamreženju. Glede na mehanizem zamreženja je pomemben tudi delež dostopnih karboksilnih skupin BTCA, ki so po zamreženju prisotne v materialu. Zato smo za določanje le teh uporabili klasično indirektno metodo metilensko modro. Kot najpomembnejši kriterij naloge, v smislu protimikrobne učinkovitosti, smo izbrali delež dostopnih aminskih skupin. Tega smo ovrednotili s spektrofotometrično metodo C.I. Acid Orange VII in mikrobiološkim testiranjem. Rezultate smo nato primerjali z rezultati, dobljenimi na osnovi klasičnega načina obdelave po tako imenovanem postopku suhega zamreženja. Na ta način smo ocenili uspešnost obdelav, izpeljanem po enem in drugem postopku.
Keywords: Zamreženje, hitozan, 1, 2, 3, 4 – butantetrakarboksilna kislina (BTCA), viskoza, FT-IR spektroskopija, pretržna sila, pretržni raztezek, kot razgubanja, metilensko modro, Acid Orange VII.
Published: 12.10.2011; Views: 2340; Downloads: 132
.pdf Full text (2,19 MB)

3.
Grafting of cotton with [beta]-cyclodextrin via poly(carboxylic acid)
Bojana Vončina, Alenka Majcen Le Marechal, 2005, original scientific article

Abstract: Cyclodextrins are cyclic oligosaccharides. Cyclodextrin molecules can form inclusion complexes with a large number of organic molecules. The properties of cyclodextrins enable them to be used in a variety of different textile applications. Cyclodextrins can act as auxiliaries in washing and dyeing processes, and they can also be fixed onto different fiber surfaces. Because of the complexing abilities of cyclodextrins, textiles with new functional properties can be prepared. Poly(carboxylic acid)s such as 1,2,3,4-butane tetracarboxylic acid (BTCA) are well-known non-formaldehyde crosslinking reagents. BTCA has four carboxylic acid groups, which can react with hydroxyl groups of cellulose and form stable ester bonds. We crosslinked -cyclodextrin molecules on hydroxyl groups of cellulose via BTCA.
Keywords: textile fibres, chemical modification, beta cyclodextrines, butane tetracarboxylic acid, BTCA, FTIR, host-guest systems, formaldehyde-free crosslinking reagents
Published: 01.06.2012; Views: 1279; Downloads: 33
URL Link to full text

4.
Grafting of ethylcellulose microcapsules onto cotton fibres
Roxana Badulescu, Vera Vivod, Darja Jaušovec, Bojana Vončina, 2008, original scientific article

Abstract: In this paper a treatment of cotton with ethylcellulose (EC) microcapsules wasinvestigated. EC microcapsules containing Rosemary oil were obtained by phase separation method. The surface and morphology of microcapsules were characterized by scanning electron microscopy (SEM). Microcapsules with a regular spherical shape in the 10-90 m size range were prepared and grafted onto cotton using the crosslinking reagent 1,2,3,4-butanetetracarboxylic acid (BTCA) in the presence of catalysts. The influence of the two catalysts, cyanamide (CA) and N,N'-dicyclohexylcarbodiimide (DCC) on curing efficiency (grafting) was investigated. SEM and Fourier transform infrared spectroscopy (FT-IR) were used to study the formation of ester bonds between BTCA and hydroxyl groups of cotton and/or hydroxyl groups of EC. When DCC was used as acatalyst, the esterification took place slowly at room temperature. In the case of CA, the cotton was cured at 110 °C for several minutes. After 2 min curing, the microcapsules, which kept their original shape, were bonded to thecotton fibers. Increasing the curing time altered the microcapsule shell. Grafting and crosslinking reactions of the thermofixed EC microcapsules onto cotton were proposed.
Keywords: textiles, chemical modification, cotton fibres, ethylcellulose, microcapsules, BTCA, SEM, FT-IR, grafting
Published: 01.06.2012; Views: 1124; Downloads: 25
URL Link to full text

5.
Viscose functionalisation with a combination of chitosan/BTCA using microwaves
Olivera Šauperl, Julija Volmajer Valh, 2013, original scientific article

Abstract: Improved hygiene and health care standards have a great impact on the development of hygiene and health care products. For this purpose, viscose is a very popular substrate. One of the most promising anti-microbial compounds of modern times is chitosan. The anti-microbial action of this polysaccharide depends on the amino group amount, which is crucial for ensuring the effectiveness of anti-microbial treated material. In textile finishing, 1,2,3,4-buthanetetracarboxylic acid (BTCA) is usually used as a non-formaldehyde crease-resistant reagent. But, on the other hand, the negatively charged carboxyl groups of BTCA can be explored as additional binding sites for positively-charged protonated amino groups of chitosan. When using microwaves, polar materials (e.g. chitosan) orient and reorient themselves according to the direction of the electro-magnetic field, which means that chitosan chain-bending may have taken place during the drying with microwaves. This could result in a higher specific surface of the chitosan and, consequently, in a higher proportion of available amino groups. It is concluded that the combination chitosan/BTCA supported by microwaves drying represents an ideal combination to increase the proportion of available amino groups.
Keywords: viskoza, protimikrobna zaščita, viscose, chitosan/BTCA, microwawes, Acid Orange VII, methylene blue, antimicrobial activity
Published: 10.07.2015; Views: 661; Downloads: 15
URL Link to full text

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