The effect of mercerisation on the electrokinetic potential of cotton

Pušić, Tanja; Grancarić, Anamarija; Soljačić, Ivo; Ribitsch, Volker

doi:10.1111/j.1478-4408.1999.tb00308.x

Cited by 31 publications

(32 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…During this process, the material swells and the polysaccharide chains are rearranged; the amount of less ordered material in the fiber rises, while the crystalline part contracts. These changes result in higher adsorption, given that mercerization increases the specific surface area of the fiber, making the hydroxyl groups of cellulose macromolecules more accessible [8,17] considered quite important for reactions occurring in heterogeneous medium, as for instance in the present work. The degree of polymerization (DP) for untreated sisal was 760 and for mercerized sisal 670, indicating that the mercerization process possibly degraded the cellulose chains breaking some of the glycosidic bonds.…”

Section: Cellulose Characterizationmentioning

confidence: 78%

Sisal cellulose acetates obtained from heterogeneous reactions

Paula¹,

Lacerda²,

Frollini³

2008

Express Polym. Lett.

View full text Add to dashboard Cite

In the present work, cellulose obtained from sisal, which is a source of rapid growth, was used. Cellulose acetates were produced in heterogeneous medium, using acetic anhydride as esterifying agent and iodine as catalyst, to check if the procedure described in the literature for commercial cellulose also is adequate to sisal cellulose. The results indicated that iodine is an excellent catalyst to obtain sisal cellulose acetates, but the reaction is so fast as described in the literature when, instead of sisal, lower average molar weight cellulose (microcrystalline) is used. The crystallinity index (Ic) of sisal cellulose acetates diminished compared to sisal cellulose, but there was no direct correlation between their degree of substitution (DS) and Ic. Probably acetyl groups were introduced more homogeneously along the short chains of microcrystalline cellulose, when compared to sisal cellulose, and then for microcrystalline cellulose acetates the Ic decreases as DS increases. Using the linear correlation that was found between degree of substitution (DS) and time reaction is possible to control the DS of sisal cellulose acetates, considering a large interval of degrees of substitution (0.3–2.8)

show abstract

Section: Cellulose Characterizationmentioning

confidence: 78%

Sisal cellulose acetates obtained from heterogeneous reactions

Paula¹,

Lacerda²,

Frollini³

2008

Express Polym. Lett.

View full text Add to dashboard Cite

show abstract

“…Figure 2 shows DTG curves of the linters cellulose, mercerized linters cellulose, and cellulose adsorption, as mercerization increases the specific surface area of the fiber, making the hydroxyl groups of the cellulose chains more accessible to solvents [11,39] . In the present work, these changes enabled the dissolution of linters cellulose in DMAc/LiCl, the solvent system used for the acetylation reaction.…”

Section: Thermal Decomposition Of Linters Cellulose and Acetatesmentioning

confidence: 99%

Thermal decomposition of mercerized linter cellulose and its acetates obtained from a homogeneous reaction

Morgado

Frollini

2011

Polímeros

View full text Add to dashboard Cite

Abstract:Cellulose acetates with different degrees of substitution (DS, from 0.6 to 1.9) were prepared from previously mercerized linter cellulose, in a homogeneous medium, using N,N-dimethylacetamide/lithium chloride as a solvent system. The influence of different degrees of substitution on the properties of cellulose acetates was investigated using thermogravimetric analyses (TGA). Quantitative methods were applied to the thermogravimetric curves in order to determine the apparent activation energy (Ea) related to the thermal decomposition of untreated and mercerized celluloses and cellulose acetates. Ea values were calculated using Broido's method and considering dynamic conditions. Ea values of 158 and 187 kJ mol -1 were obtained for untreated and mercerized cellulose, respectively. A previous study showed that C6OH is the most reactive site for acetylation, probably due to the steric hindrance of C2 and C3. The C6OH takes part in the first step of cellulose decomposition, leading to the formation of levoglucosan and, when it is changed to C6OCOCH 3 , the results indicate that the mechanism of thermal decomposition changes to one with a lower Ea. A linear correlation between Ea and the DS of the acetates prepared in the present work was identified. Keywords: Linter cellulose, cellulose acetates, thermal decomposition. Decomposição Térmica de Celulose de Linter Mercerizado e seus Acetatos Obtidos a partir de Reação HomogêneaResumo: Acetatos de celulose com graus de substituição, GS, variando entre 0,6 e 1,9, foram preparados previamente a partir de celulose de linter mercerizado, em meio homogêneo, usando N,N-dimetilacetamida/cloreto de lítio como sistema de solvente. A influência de diferentes graus de substituição nas propriedades dos acetatos de celulose foi investigada usando a análise termogravimétrica (TGA). Métodos quantitativos foram aplicados nas curvas termogravimétricas obtidas a fim de determinar a energia de ativação aparente (Ea) relacionado à decomposição térmica de celulose não-tratada e mercerizada e acetatos de celulose. Valores de Ea foram calculados usando o método de Broido e considerando condições dinâmicas. Valores de Ea de 158 e 187 kJ mol -1 foram obtidos para a celulose não-tratada e mercerizada, respectivamente. Em trabalho anterior verificou-se que o C6OH é o sítio mais reativo na acetilação, provavelmente devido ao impedimento estérico de C2 e C3. O C6OH participa da primeira etapa de decomposição da celulose, levando à formação de levoglucosana e, quando se tem a substituição para C6OCOCH 3 , o resultado indica que o mecanismo de decomposição térmica muda para um com Ea menor. Uma correlação linear entre Ea e o GS dos acetatos preparados no presente trabalho foi identificada. Palavras-chave: Celulose de linter, acetatos de celulose, decomposição térmica.

show abstract

“…Zeta ( ) potential is not a constant value for textiles, but gives information about the nature and dissociation of functional groups, hydrophilicity or hydrophobicity of the fibre surface, as well as ions or water sorption. This potential plays an important role in the electrical characterisation of textiles in wet processing [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…A significant influence on the sorption properties of fi bres is the amount of accessible groups (i.e. hydroxy, carboxy, sulphate and amino groups) and the portion of amorphous regions where the adsorption processes take place [2][3][4][5][6][7][8][9][10]16,17].…”

Section: Introductionmentioning

confidence: 99%

Electrokinetic properties of textile fabrics

Grancarić

Tarbuk

Pušić

2005

Coloration Technology

129

View full text Add to dashboard Cite

This paper reports electrokinetic phenomena concerning the properties of textile fabrics that are crucial for dyeing and finishing processes. These interface phenomena influence the adsorption of surfactants, optical brighteners, dyes and finishing agents due to interaction forces between the fibre surface and solution. Zeta potential, isoelectric point, point of zero charge and the amount of surface charge of standard adjacent fabrics (cotton, wool, viscose rayon, polyamide, polyester and acrylic) have been determined. Electrokinetic potential was measured by a method involving streaming potential/current using an electrokinetic analyser. The specific amount of surface charge was calculated by a back‐titration method.

show abstract

The effect of mercerisation on the electrokinetic potential of cotton

Cited by 31 publications

References 9 publications

Sisal cellulose acetates obtained from heterogeneous reactions

Sisal cellulose acetates obtained from heterogeneous reactions

Thermal decomposition of mercerized linter cellulose and its acetates obtained from a homogeneous reaction

Electrokinetic properties of textile fabrics

Contact Info

Product

Resources

About