THE STUDY OF ESTERQUAT ADSORPTION ON COTTON AND POLYESTER/COTTON FABRICS

Tanja PUŠIĆ Tihana DEKANIĆ Katia GRGIĆ Dražen ĆUTUK Suzana JUREŠIĆ Tea KAURIN

DSDMAC

EQ

+R CH

3

N

R CH3

Cl

R = C16 - C18

Table 1: Technical parameters of tested fabrics

Fabric Cotton Polyester/Cotton

Label C P/C

Composition [%] 100 50/50

Surface area [g/m2] 176 115

Density Warp [cm-1] 25 54

Weft [cm-1] 25 24

Micrograph, magnification 235.2x

Adsorption of esterquat (EQ) • EQ: STEPANTEX VK 90 Methyl bis

[ethyl (tallowate)]-2-hydroxyethyl ammonium methyl sulfat (Stephan, France)

• : 0.2 and 0.5 g/l • M: 5.0 g • BR: 1:20 • T : 20 °C • t : 30 minutes • Apparatus: Linitest apparatus,

Original Hanau • Drying: air conditions

Label Description

C Untreated cotton fabric (control)

P/C Untreated polyester cotton fabric (control)

BPB Treatment with Bromo Phenol Blue

EQ_0.2/EQ_0.5 Esterquat applied in the concentration of 0.2 and 0.5 g/l

C_EQ_0.2 Cotton fabric softened with 0.2 g/l esterquat

C_EQ_0.5 Cotton fabric softened with 0.5 g/l esterquat

P/C_EQ_0.2 Polyester cotton fabric softened with 0.2 g/l esterquat

P/C_EQ_0.5 Polyester cotton fabric softened with 0.5 g/l esterquat

Table 2: Labels and description of samples

METHODS

Rewetting properties of fabrics after treatment with esterquat were determined by vertical wicking method using Victoria blue 4R (C.I. Basic blue 7)

Softener deposition amount on tested samples was checked with Bromo Phenol Blue (BPB)

(C.I. Acid Blue)

The coloration of the samples treated with BPB was evaluated by spectral L*a*b* values, using DataColor Spectraflash SF 600 Plus CT.

Surface properties of the fabrics were characterized by zeta potential calculated from streaming potential. Fabrics were placed in the adjustable gap cell of an A. Paar GmbH instrument, SurPASS.

Adsorption/desorption of esterquat on cotton and polyester/cotton fabrics was also done in a SurPASS

•Adsorption/desorption of EQ on cotton and polyester/cotton fabrics

Streaming potential of the fabrics was measured varying: • pH of an electrolyte solution (1 mmol/l

KCl) through step titration

•SurPASS, A. Paar GmbH, Austria

SurPASS, A. Paar GmbH, Austria

Fabric

C P/C

Victoria blue 4R migration after 5 minutes [cm]

Treated with 0.2 g/l of esterquat

0.0 0.0

Treated with 0.5 g/l of esterquat

0.0 0.0

Untreated (control) 0.9 0.6

Table 3: Victoria blue 4R migration

Fabric WCIE TV Y

C 72.84 -1.32 83.06

C_EQ_0.2 71.80 -1.40 82.16

C_EQ_0.5 72.35 -1.48 82.52

P/C 68.80 -1.56 81.04

P/C_EQ_0.2 68.04 -1.68 80.42

P/C_EQ_0.5 68.62 -1.70 80.82

Table 4: Whiteness evaluation of the fabrics before and after the adsorption of esterquat

SurPASS, A. Paar GmbH, Austria

Fabric a* b* L*

C_U 0.30 2.21 93.03

C_U_BPB 0.06 1.11 91.79

C_EQ_0.2_BPB 2.26 -39.08 59.74

C_EQ_0.5_BPB 4.76 -42.31 56.09

Table 5: Spectral characteristics (L*a*b*) of cotton fabrics

Figure 1: Zeta potential of cotton and polyester/cotton fabrics varying by 0.001 mol/l KCl

Figure 2: Adsorption of esterquat onto cotton based fabrics in SurPASS

Sample Weight [g] V EQ [ml] n [10-3

mmol]*

PZC [10-5

mmol/ml/g] P/C 0.0452 0.9 0.1863 0.8228

C 0.0688 1.2 0.2484 0.7204

Table 3: Point of zero charge (PZC) of cotton and polyester/cotton samples - adsorption of esterquat

Figure 3: The study of esterquat adsorption and desorption in SurPASS

CONCLUSIONS: • Adsorption of EQ on cotton and

polyester/cotton fabrics is achieved through the process of exhaustion and special titration procedure in SurPASS analyser.

• It was found that cotton and polyester/cotton fabrics after softening with esterquat in concentrations 0.2 and 0.5 g/l:

• retained whiteness • lost re-wetting properties. • EQ deposits on cotton and polyester/cotton

fabric were proved by blue coloration (BPB).

• The results obtained have confirmed a

significant impact of fabric surface charge on the adsorption of esterquat on cotton and polyester/cotton fabrics.

• The appropriateness of electrokinetic measurements prior to the implementation of adsorption through exhaustion process is confirmed.

• Adsorption and desorption of esterquat in SurPASS can provide information not only from a scientific point of view but also from a practical one, which can improve the technological application and stability of esterquats in softening textiles.

The work has been supported by Croatian Science Foundation under the project ADVANCETEX 9967: Advanced textile materials by targeted surface modification.

Thanks for your attention