Investigation of the Usage Characteristics of Environmentally Friendly Water-Repellent Chemicals on Cotton Fabrics
Journal Archive
doi: 10.1595/205651323X16684366635676
Investigation of the Usage Characteristics of Environmentally Friendly Water-Repellent Chemicals on Cotton Fabrics
Improving sustainability of surface coatings
Article Synopsis
Fabrics with water-repellent properties are widely valued in the textile industry. It is known that fluorocarbon compounds, which are widely used for this purpose, are harmful to the environment. Therefore, within the scope of this study, a water-repellent chemical that does not contain fluorocarbon compounds was used to treat 100% cotton fabrics and compared with fluorocarbon compounds. The results show that the environmentally friendly chemical is at least as effective as the fluorocarbon compounds. According to the spray test, water repellency at ISO 5 level was obtained. In addition, the fabrics’ usage properties were assessed and high water vapour permeability, air permeability and low bending stiffness (280 mg cm) were obtained. This has yielded important results in terms of sustainability and the potential for eliminating the use of fluorocarbons for this application.
1. Introduction
Wetting a fibrous material affects both the performance of the final product obtained from the material and the production processes that the material will go through until it becomes the final product. Wetting can be defined as the condition that occurs when a solid surface comes into contact with a liquid. Wettability is defined as the potential for a solid surface to interact with a liquid. According to Harnett and Metha, wettability is defined as the behaviour of fabric, yarn or fibre in contact with a liquid. It also describes the interaction of the liquid with the substrates of the fabric before it is absorbed into the fabric (1, 2).
In order for a liquid to enter a fibrous structure, it must first wet the surface of the fibrous structure. Then, this liquid will be transported towards the interfibre spaces by means of capillary forces and the absorption process will take place. The interaction of the liquid molecules in a liquid mass on the surface of the fibrous material is in a state of equilibrium. However, the fibrous material applies an equal tensile force to this liquid mass from every point, and in this case, the balance is disturbed. As a result, free energy is released on the liquid surface. This released energy is called ‘free surface energy’ and tends to keep the surface area of the liquid to a minimum, preventing it from spreading to the solid surface and thus keeping it in balance. For a liquid to completely wet a solid surface, the surface energy of the solid surface must exceed the free surface energy of the liquid (1, 3–5).
An important parameter for wettability is the contact angle. The shape of the liquid placed on a solid surface without dispersion remains constant and the contact angle, θ, can be measured. High contact angle values indicate poor wettability, low angles indicate good wettability (6).
Expectations from textile surfaces are increasing and textile materials are gaining different usage properties according to expectations. Water and dirt repellency is one of these expectations. Demand for waterproof but breathable products with features such as water, oil and dirt repellency is increasing (6–8). Water-repellent and waterproofing applications have been combined in a single product and fabric and textile products with water repellency, breathability and adequate performance have been produced (6, 8, 9). In the 1990s, the hydrophobic properties of plant leaves such as lotus were explained by examination of their microstructures, which provide excellent water repellency. Since then, with the increasing possibilities in chemical technology, artificial hydrophobic surfaces have been developed and applied in various fields (10, 11).
The basis of the water-repellent process is to create a water-repellent membrane on the fabric surface with chemical substances that have a long-chain water-repellent group. In short, the principle of water repellency is to increase the surface tension of the fabric against water. As a water-repellent membrane is created only on the surface of the fabric, the internal structure and pore structure of the fabric are not adversely affected in any way. This is the most characteristic feature of water repellency in such applications. Since the pores of the fabric are not closed, skin respiration and sweat transfer in clothing are not adversely affected. In fact, fabrics with water-repellent treatment are drier and more air permeable than untreated fabrics, since the water vapour coming out of the body will completely move away without condensation. Again, the fact that the effect remains on the surface in the water-repellent process can best be explained by the difference between the amount of water that the fabric absorbs into its structure and the amount of water (swelling value) that it can hold in its structure (8, 11–19).
Fluorocarbons are the most widely and effectively used chemicals in the textile industry to impart water repellency to fabrics. Since the barrier formed by fluorocarbon is very strong, it effectively repels even oil and chemicals. Fluorocarbon-based water repellents are often used in the technical textile industry for protective workwear for manufacturing plants and against severe inclement weather. But this is not their only application. Because fluorocarbons are very durable, they are also appreciated by consumers. Therefore, it is clear that the problem with fluorocarbons is not their performance efficiency. The main problem is their byproducts: perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Both are persistent, bioaccumulative and toxic chemicals. Currently, no water- and oil-repellent chemical manufacturer in the world can produce fluorocarbons without PFOS and PFOA. This means that fluorocarbon-based water repellents will always be bad news for the environment (20–25).
C8 fluorocarbons used in recent studies have been converted to C6. Since the chains of C6 fluorocarbons are shorter, the rate of occurrence of the mentioned byproducts is much lower (26). However, from an environmental point of view, this is not enough. Due to recent pressure from environmental organisations and global brands, and the dangers posed by the byproducts of C6 fluorocarbons and impurities that may be present, the industry has turned to alternative water-repellent chemistry: fluorine-free water repellents. For this reason, examining the effectiveness of fluorocarbon-free chemicals in adding water repellency has gained importance in terms of environmental awareness and sustainability (27–34). While fluorinated compounds offer high performance in imparting water-repellent properties to textile surfaces, non-fluorine water repellents offer an economical and ecological alternative to these compounds.
However, there are difficulties in obtaining high contact angles with conventional methods. On these important disadvantages, many researchers have started to search for new methods that can replace conventionally used systems in the textile industry. Adding hydrophobic properties to the surface by using the sol-gel method has been presented as an alternative method. In order to obtain micro- and nano-structured water- and oil-repellent surfaces, other methods such as electrospinning, chemical vapour deposition and layer-by-layer coating are used as well as the sol-gel method (35–46). A new generation of dendrimer-based water-, oil- and dirt-repellent chemicals have been identified as offering superior properties (47).
In this study, a water-repellent chemical that does not contain fluorocarbons was compared with different fluorocarbon compounds used in the sector. The chemicals used were applied to 100% cotton fabrics by the pad-dry-cure method. Images of the treated chemicals on the surface were visualised by scanning electron microscopy (SEM). As a result of the transfer processes, the water repellency properties of the fabrics were evaluated by spray test and contact angle measurements. In order to evaluate the usage properties of the fabrics, bending stiffness and water vapour permeability analyses were carried out.
2. Material and Method
2.1 Material
In this research, desized, plain weave cotton fabric (specific weight 130 g m–2) was used. C6-fluorocarbon polymer and C8-fluorocarbon polymer were used as conventional water-repellent chemicals and were supplied by Rudolf Duraner, Turkey. To compare the effectiveness of a water-repellent chemical that does not contain fluorocarbons, a dendrimer based non-fluorinated water-repellent finishing agent was supplied by Rudolf Duraner. Dendrimer technology was used and the chemical does not contain fluorocarbons, alkylphenol ethoxylates (APEO) or other organic halogenated compounds. Acetic acid was of laboratory-reagent grade to adjust the pH. The structures of the water-repellent chemicals are shown in Figure 1.
Fig. 1.
Chemical structures of water-repellent chemicals: (a) C6-fluorocarbon polymer; (b) C8-fluorocarbon polymer; (c) dendrimer based non-fluorinated polymer (48)
2.2 Application Method
The three different water-repellent chemicals were applied to cotton fabrics in three different concentrations (50 g l–1, 75 g l–1 and 100 g l–1). Primarily, products were dissolved in water and the pH of the solution was adjusted to pH 5.0–5.5 by acetic acid. Then, the fabric was squeezed between rollers to 85% wet pick-up. Fabrics were dried in a circulating air oven at 100°C. To achieve long lasting effect, the fabric was exposed to a fixation process for 2 min at 160°C in a laboratory stenter. Fabric codes are stated in Table I. The final dry add-on was 20 wt%.
Table I
Fabric Codes of Water-Repellent Chemicals Transferred
2.3 Scanning Electron Microscopy Analysis
The morphologic properties of the fabrics following application of the water-repellent chemicals were evaluated using SEM (QuantaTM 250 FEG, FEI, USA). Samples were gold-coated (15 mA, 2 min) to assure electrical conductivity. The measurements were taken at 2 kV accelerating voltage. The images were taken at 500× magnifcation.
2.4 Contact Angle Analysis
The contact angle is expressed as the angle formed by a liquid drop with a solid surface as an indicator of the degree of wettability (surface tension and contact angle measurement). Contact angle measurements were made to examine the behaviour of the samples against wetting. Measurements were made at 25°C using a Theta Lite (Biolin Scientific, Sweden) model contact angle device. With the help of the device camera, an image of a water droplet of volume approximately 5 μl dripped onto the surface was recorded for 10 s. Experiments were carried out in five repetitions.
2.5 Spray Test Method
Spray test was done according to the ISO 4920:2012 standard (49). By looking at the standard sample photographs, grades are given according to the wetting effect of the drops on the surface. Before testing, the samples were conditioned for 24 h at 20±2°C and 65±2% relative humidity. The treated fabrics (18 cm × 18 cm) were placed taut on the collar. 250 ml of water placed in a funnel with a certain diameter and number of dripping holes is poured onto the slightly stretched sample surface with a 45° inclination from a height of 150 mm over 25–30 s, and an evaluation is made by comparing it with the photographs (depending on the adhesion of the drops to the surface). Non-wet fabric is rated ISO 5, fully wet fabric 0 (49). The evaluation images of the spray test are shown in Figure 2.
Fig. 2.
Photographs of spray test evaluation (49). Permission to reproduce extracts from British Standards is granted by BSI, UK
2.6 Bending Rigidity
Bending length of samples (in cm) was measured according to TS 1409 (50). It was carried out on a Shirley stiffness tester (SDL Atlas Textile Testing Solutions, UK). In TS 1409, the sample is held at one end and is released from the other end under its own weight. When the tip of the fabric sample reaches a slope of 41.5° below the horizontal, the overhanging length is measured and this length gives twice the bending length (51–53). In addition, bending rigidity in the warp and weft directions were calculated considering the bending lengths and fabric weight. Equation (i) is used to calculate the bending stiffness:
Here, G is bending rigidity in mg cm; W is fabric weight in g m–2; L represents the bending length in cm. Experiments were carried out in five repetitions.
2.7 Water Vapour Permeability
In order to examine the breathability of the fabrics, their water vapour permeability was tested. For this purpose, M261 model water vapour permeability tester (SDL Atlas, USA) was used in accordance with BS 7209 standard (54). Experiments were carried out in five repetitions.
2.8 Air Permeability
The air permeability values of the samples were determined by measuring the amount of air passing through 20 cm2 of fabric surface in millimetres per second with a pressure difference of 100 Pa in the air permeability device, according to ISO 9237:1995 (55). Results are expressed in millimetres per second. This test was repeated from ten different parts of the fabric and the average was taken.
3. Results and Discussion
In this study, water-repellent chemicals were successfully treated by pad-dry-cure method in three different concentrations. SEM analysis of water-repellent chemical treated fabrics are given in Table I. 500× magnification images are given in Figure 3.
Fig. 3.
SEM images of water-repellent chemical treated fabrics: (a) untreated fabric; (b) C6-50; (c) C6-75; (d) C6-100; (e) C8-50; (f) C8-75; (g) C8-100; (h) non-fluorinated-50; (i) non-fluorinated-75; (j) non-fluorinated-100
When the SEM images for cotton fabrics are examined, it can be seen that the fibres of the untreated fabric have a smoother surface. The chemicals can be observed on the surface of the treated fabrics. As the concentrations of the treated chemicals on the surface increase, their presence on the fibres can be more clearly seen. In particular, the non-fluorinated-100 chemical is clearly visible on the surface of the treated fabric. It can be seen that the chemicals are successfully adhered to the fabric.
The contact angle measurements of the fabrics with the water-repellent chemical used in the study are shown in Figure 4. The contact angle is expressed as the angle formed by a liquid drop with the solid surface as an indicator of the degree of wettability. It is known that the structure becomes more hydrophobic as the contact angle increases. It can be seen that the contact angle increases as the concentration ratio increases for all three chemicals and these values are 80.25±3°, 84.80±3° and 87.92±4° for C6, C8 and non-fluorinated, respectively, in the 100 g l–1 concentration. When the chemicals are compared, it can be seen that the highest contact angle value is observed with the non-fluorinated chemical. This shows that more environmentally friendly chemicals can be used instead of fluorocarbons as water-repellent chemicals.
Fig. 4.
Contact angle images of water-repellent chemical treated fabrics: (a) untreated fabric; (b) C6-50; (c) C6-75; (d) C6-100; (e) C8-50; (f) C8-75; (g) C8-100; (h) non-fluorinated-50; (i) non-fluorinated-75; (j) non-fluorinated-100
The spray rate test is a test to determine the water repellency of materials using a ‘shower test’. Spray test results of fabrics are shown in Table II. These results and visual evaluations show that the fabrics with 100 g l–1 concentration of chemical have the highest water repellency at ISO 5. These results agree with the contact angle measurements. ISO 3 value was obtained for the C6 chemical at 50 g l–1 and 75 g l–1 concentrations. The more environmentally friendly non-fluorinated chemical was shown to provide excellent water-repellent properties to cotton fabric. This shows that this chemical can be used as a replacement for fluorocarbon compounds.
Table II
Spray Test Results of Fabrics
Bending rigidity analysis is used to examine the performance and comfort properties of fabrics. Results are given in Table III. Flexural strength is the resistance of a fabric to bending. Fabrics with high flexural strength are stiff and drape decreases as flexural strength increases. The bending strength of a fabric depends on the structure of the yarns, the fibre structure, the fabric weave and the applied finishing processes. Rigid fabrics require more length to be able to bend sufficiently. Therefore, high bending length values mean that the fabric is stiff. In other words, fabrics with a high bending length do not show much drape. The bending length of the fabric and accordingly the bending stiffness increase as these chemicals restrict the movement of the yarns relative to each other due to the chemical transfer to the fabric (51, 52). In the present study, there was no significant difference between the untreated fabric and the treated fabrics. This shows that the treated chemicals do not have a negative effect on the handling of the fabrics for their usage properties.
Table III
Bending Length and Bending Rigidity Results of Fabrics
Water vapour permeability and air permeability analysis was carried out to examine the comfort properties of the fabrics obtained. The results are tabulated in Table IV. The water vapour permeability of a material plays an important part in evaluating the physiological wearing comfort of clothing systems and determining the performance characteristics of textile materials. The highest water vapour permeability was seen for the untreated cotton fabric with permeability value 997.91 g m–2 24 h–1. The fabrics treated with water-repellent chemicals by the pad-dry-cure method gave similar results to the untreated fabric. Although the value decreases as the concentration of chemicals increases, the decrease is small and is not expected to affect the comfort properties. The results of the air permeability analysis show that the water-repellent finish reduces the air permeability of the fabric. The air permeability value decreases as the concentration of the transferred chemical increases. However, the values obtained are not at a level to affect the performance properties of cotton fabrics.
Table IV
Water Vapour Permeability Results of Fabrics
4. Conclusion
Within the scope of this study, an environmentally friendly chemical has been used as an alternative to conventional widely used water-repellent finishing chemicals containing fluorocarbons. 100% cotton fabrics were treated using the pad-dry-cure method at three different concentrations and compared with two different chemicals containing fluorocarbons. SEM analysis showed that the water-repellent finishing chemicals were successfully adhered onto the fabrics. Contact angle and spray test analyses were carried out to evaluate the water repellency properties. The contact angle values (approximately 88°) and the water repellency values (ISO 5) increased as the chemical concentration increased. The non-fluorinated water-repellent chemical, which does not contain fluorocarbons, gave better or similar water repellency values compared to the conventional chemicals. Water vapour permeability, air permeability and bending stiffness tests were carried out to examine the usage properties of fabrics. It was determined that the usage characteristics of the fabrics with chemical transfer remained similar to the untreated fabric. In the light of all these results, it is seen that the dendrimer-based non-fluorinated chemical, which does not contain fluorocarbons, can be used as an alternative to fluorocarbon compounds. This will provide great ecological and sustainability benefit.
References
- 1.
A. Patnaik, R. S. Rengasamy, V. K. Kothari and A. Ghosh, Text. Prog., 2006, 38, (1), 1 LINK https://doi.org/10.1533/jotp.2006.38.1.1
- 2.
P. R. Harnett and P. N. Mehta, Text. Res. J., 1984, 54, (7), 471 LINK https://doi.org/10.1177/004051758405400710
- 3.
B. Miller, ‘The Wetting of Fibers’, in “Surface Characteristics of Fibers and Textiles”, ed. M. J. Schick, Ch. 11, Part II, Marcel Dekker Inc, New York, USA, 1977, p. 417 LINK https://www.taylorfrancis.com/chapters/edit/10.1201/9780203737811-1/wetting-fibers-bernard-miller?context=ubx&refId=916ea167-ded1-4695-bb95-b535986d3a1f
- 4.
B. Miller and R. A. Young, Text. Res. J., 1975, 45, (5), 359 LINK https://doi.org/10.1177/004051757504500501
- 5.
B. P. Saville, ‘Comfort’, in “Physical Testing of Textiles”, Ch. 8, Woodhead Publishing Ltd, Cambridge, UK, 1999, pp. 209–243 LINK https://doi.org/10.1533/9781845690151.209
- 6.
C. Loghin, L. Ciobanu, D. Ionesi, E. Loghin, and I. Cristian, ‘Part One: Principles of Waterproofing and Water Repellency in Textiles: Introduction to Waterproof and Water Repellent Textiles’, in “Waterproof and Water Repellent Textiles and Clothing”, ed. J. T. Williams, The Textile Institute Book Series, Ch. 1, Elsevier Ltd, Duxford, UK, 2018, pp. 3–24 LINK https://doi.org/10.1016/B978-0-08-101212-3.00001-0
- 7.
K. Lacasse and W. Baumann, “Textile Chemicals: Environmental Data and Facts”, Springer-Verlag, Berlin, Germany, 2004, 1180 pp LINK https://doi.org/10.1007/978-3-642-18898-5
- 8.
G. Ozcan, Text. Res. J., 2007, 77, (4), 265 LINK https://doi.org/10.1177/0040517507080619
- 9.
A. Aksoy and S. Kaplan, Tekst. Teknol. Elektron. Derg., 2011, 5, (2), 51
- 10.
G. R. Lomax, Textiles, 1991, 20, (4), 12
- 11.
H. K. Rouette, “Encyclopedia of Textile Finishing”, Springer-Verlag, Berlin, Germany, 2001, pp. 235–242
- 12.
G. Oğultürk, ‘Dokuma Kumaşlarda Su İticilik Ve Buruşmazlık Özelliklerinin Tek Adımda İyileştirilmesi’, Masters Thesis, Institute of Science, İstanbul Technical University, İstanbul, Turkey, June, 2008, 106 pp LINK http://hdl.handle.net/11527/4584
- 13.
M. H. Shim, J. Kim and C. H. Park, Text. Res. J., 2014, 84, (12), 1268 LINK https://doi.org/10.1177/0040517513495945
- 14.
B. Simončič, S. Hadžić, J. Vasiljević, L. Černe, B. Tomšič, I. Jerman, B. Orel and J. Medved, Cellulose, 2014, 21, (1), 595 LINK https://doi.org/10.1007/s10570-013-0103-4
- 15.
T. L. Vigo, “Textile Processing and Properties: Preparation, Dyeing, Finishing and Performance”, Textile Science and Technology, Vol. 11, Elsevier Science BV, Amsterdam, The Netherlands, 1994, 479 pp
- 16.
Y. E. Yüksel and Y. Korkmaz, Int. J. Clothing Sci. Technol., 2019, 31, (5), 693 LINK https://doi.org/10.1108/IJCST-09-2018-0119
- 17.
H. T. K. Trinh and M. H. Bùi, VNUHCM J. Eng. Technol., 2021, 4, (1), 697 LINK https://doi.org/10.32508/stdjet.v4i1.788
- 18.
M. Kowalski, R. Salerno-Kochan, I. Kamińska and M. Cieślak, Materials, 2022, 15, (11), 3825 LINK https://doi.org/10.3390/ma15113825
- 19.
H. A. Schuyten, J. D. Reid, J. W. Weaver and J. G. Frick, Text. Res. J., 1948, 18, (8), 490 LINK https://doi.org/10.1177/004051754801800806
- 20.
N. Ertürk, ‘A Study about the Performance Criteria of Different Fluorocarbon Resins’, Master Thesis, Graduate School of Natural and Applied Sciences, Ege University, İzmir, Turkey, 2010
- 21.
G. Duschek, Melliand Int., 2001, 7, (8), 148
- 22.
U. Sayed, and P. Dabhi, ‘Finishing of Textiles with Fluorocarbons’, in “Waterproof and Water Repellent Textiles and Clothing”, ed. J. Williams, The Textile Institute Book Series, Ch. 6, Elsevier Ltd, Cambridge, UK, 2018, pp. 139–152 LINK https://doi.org/10.1016/B978-0-08-101212-3.00006-X
- 23.
A. Khatton, M. N. Islam, M. Hossen, J. Sarker, H. A. Sikder and A. M. S. Chowdhury, Saudi J. Eng. Technol., 2022, 7, (3), 128 LINK https://doi.org/10.36348/sjet.2022.v07i03.002
- 24.
R. Grottenmüller, Melliand Türk., 1999, 1, 50
- 25.
N. A. Ivanova and A. K. Zaretskaya, Appl. Surf. Sci., 2010, 257, (5), 1800 LINK https://doi.org/10.1016/j.apsusc.2010.09.021
- 26.
M. Mohsin, N. Sarwar, S. Ahmad, A. Rasheed, F. Ahmad, A. Afzal and S. Zafar, J. Cleaner Prod., 2016, 112, (4), 3525 LINK https://doi.org/10.1016/j.jclepro.2015.10.045
- 27.
M. Mohsin, A. Farooq, N. Abbas, U. Noreen, N. Sarwar and A. Khan, J. Nat. Fibers, 2016, 13, (3), 261 LINK https://doi.org/10.1080/15440478.2015.1005329
- 28.
K. P. Chowdhury, S. Chowdhury, M. A. Hosain, A. Al Mamun, Sk. N. Alahi and Md. S. Rahman, Int. J. Curr. Eng. Technol., 2018, 8, (2), 393 LINK https://doi.org/10.14741/ijcet/v.8.2.34
- 29.
R. Sharif, M. Mohsin, N. Ramzan, S. Sardar, S. W. Ahmad and W. Ahtisham, J. Nat. Fibers, 2022, 19, (13), 5637 LINK https://doi.org/10.1080/15440478.2021.1889429
- 30.
R. Sharif, M. Mohsin, S. Sardar, N. Ramzan and Z. A. Raza, J. Nat. Fibers, 2022, 19, (16), 12473 LINK https://doi.org/10.1080/15440478.2022.2072995
- 31.
Y. Wang, V. Baheti, M. Z. Khan, M. Viková, K. Yang, T. Yang and J. Militký, J. Text. Inst., 2022, 113, (10), 2238 LINK https://doi.org/10.1080/00405000.2021.1975905
- 32.
Y. Jiang, Y. Weng, C. Wang, Z. Zhang, P. Jing, C. Xu and J. Du, J. Text. Inst., 2022, latest articles LINK https://doi.org/10.1080/00405000.2022.2093079
- 33.
R. Sharif, M. Mohsin, N. Ramzan, S. W. Ahmad and H. G. Qutab, J. Nat. Fibers, 2022, 19, (5), 1632 LINK https://doi.org/10.1080/15440478.2020.1787918
- 34.
R. Sharif, M. Mohsin, N. Ramzan, S. Sardar and W. Anam, J. Nat. Fibers, 2022, 19, (16), 14077 LINK https://doi.org/10.1080/15440478.2022.2116141
- 35.
L. Černe and B. Simončič, Text. Res. J., 2004, 74, (5), 426 LINK https://doi.org/10.1177/004051750407400509
- 36.
G. Lewandowski, E. Meissner and E. Milchert, J. Hazard. Mater., 2006, 136, (3), 385 LINK https://doi.org/10.1016/j.jhazmat.2006.04.017
- 37.
W. Tang, Y. Huang, F.-L. Qing, J. Appl. Polym. Sci., 2011, 119, (1), 84 LINK https://doi.org/10.1002/app.32605
- 38.
G. Y. Bae, B. G. Min, Y. G. Jeong, S. C. Lee, J. H. Jang and G. H. Koo, J. Colloid Interface Sci., 2009, 337, (1), 170 LINK https://doi.org/10.1016/j.jcis.2009.04.066
- 39.
S. Gowri, L. Almeida, T. Amorim, N. Carneiro, A. P. Souto and M. F. Esteves, Textile Res. J., 2010, 80, (13), 1290 LINK https://doi.org/10.1177/0040517509357652
- 40.
M. Z. Khan, V. Baheti, J. Militky, A. Ali and M. Vikova, Carbohydr. Polym., 2018, 202, 571 LINK https://doi.org/10.1016/j.carbpol.2018.08.145
- 41.
M. Z. Khan, J. Militky, M. Petru, B. Tomková, A. Ali, E. Tören and S. Perveen, Eur. Polym. J., 2022, 178, 111481 LINK https://doi.org/10.1016/j.eurpolymj.2022.111481
- 42.
M. Z. Khan, J. Militky, V. Baheti, M. Fijalkowski, J. Wiener, L. Voleský and K. Adach, Cellulose, 2020, 27, (17), 10519 LINK https://doi.org/10.1007/s10570-020-03495-x
- 43.
M. Z. Khan, V. Baheti, J. Militky, J. Wiener and A. Ali, J. Ind. Text., 2020, 50, (4), 543 LINK https://doi.org/10.1177/1528083719836938
- 44.
S. Riaz, M. Ashraf, M. T. Hussain, A. Younus, M. Raza and A. Nosheen, Fibers Polym., 2021, 22, (1), 109 LINK https://doi.org/10.1007/s12221-021-9245-4
- 45.
M. Z. Khan, V. Baheti, M. Ashraf, T. Hussain, A. Ali, A. Javid and A. Rehman, Fibers Polym., 2018, 19, (8), 1647 LINK https://doi.org/10.1007/s12221-018-7935-3
- 46.
M. Z. Khan, J. Militky, V. Baheti, J. Wiener and M. Vik, J. Text. Inst., 2021, 112, (10), 1639 LINK https://doi.org/10.1080/00405000.2020.1834235
- 47.
S. Ghosh, S. Yadav, N. Vasanthan and G. Sekosan, J. Appl. Polym. Sci., 2010, 115, (2), 716 LINK https://doi.org/10.1002/app.31127
- 48.
O. Namırtı and R. Atav, Pamukkale Üniv. Müh. Bilim. Derg., 2011, 17, (2), 109 LINK http://pajes.pau.edu.tr/jvi.aspx?pdir=pajes&plng=tur&un=PAJES-52504&look4=
- 49.
‘Textile Fabrics – Determination of Resistance to Surface Wetting (Spray Test)’, ISO 4920:2012, International Organization for Standardization, Geneva, Switzerland, 2012, 7 pp LINK https://www.iso.org/standard/50706.html
- 50.
‘Stiffness Determination of Woven Textiles’, TS 1409, Turkish Standards Institute, Ankara, Turkey, 1973, 5 pp LINK https://intweb.tse.org.tr/Standard/Standard/Standard.aspx?081118051115108051104119110104055047105102120088111043113104073083069085108099112057105109065097
- 51.
G. E. Cusick, J. Text. Inst. Trans., 1965, 56, (11), T 596 LINK https://doi.org/10.1080/19447026508662319
- 52.
N. Erdumlu, Tekst. Konf., 2015, 25, (1), 47 LINK https://dergipark.org.tr/en/download/article-file/218277
- 53.
N. Özdil, A. T. Özgüney, G. S. Mengüç and S. Sertsöz, Tekst. Konf., 2014, 24, (2), 169 LINK https://dergipark.org.tr/en/download/article-file/218226
- 54.
‘Specification for Water Vapour Permeable Apparel Fabrics’, BS 7209:1990, British Standards Institution, London, UK, 1990 LINK https://knowledge.bsigroup.com/products/specification-for-water-vapour-permeable-apparel-fabrics/standard
- 55.
‘Textiles — Determination of the Permeability of Fabrics to Air’, ISO 9237:1995, International Organization for Standardization, Geneva, Switzerland, 1995, 5 pp LINK https://www.iso.org/standard/16869.html