Multipurpose Nonwoven Viscose/Polypropylene Fabrics: Effect of Fabric Characteristics on Sorption and Dielectric Properties Koviljka A. Asanovic , 1 Dragana D. Cerovic, 2,3 Mirjana M. Kostic, 1 Slavica B. Maletic, 3 Ana D. Kramar 1 1 Department of Textile Engineering, Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, 11000, Serbia 2 The College of Textile Design, Technology and Management, Belgrade, 11000, Serbia 3 Faculty of Physics, University of Belgrade, Belgrade, 11000, Serbia Correspondence to: K. A. Asanovic (E-mail: koka@tmf.bg.ac.rs) Received 24 November 2017; accepted 28 March 2018; published online 00 Month 2018 DOI: 10.1002/polb.24611 ABSTRACT: In this work, sorption and dielectric properties of viscose/polypropylene multipurpose nonwoven fabrics were examined. The analysis of sorption behavior showed that the changes of the water absorptive capacity, the height of capil- lary rise and water retention value are in a function of viscose fiber content, total porosity, the pore size and used web bond- ing process. It is observed that dielectric properties at frequen- cies from 30 Hz to 140 kHz, for samples exposed to different relative air humidity and wet samples, are dependent on vis- cose fiber content, web bonding process, frequency of electric field and bulk free water content. The effective dielectric permeability of wet samples rapidly decreases with an increase in frequency up to 3 kHz while spectra of the AC specific elec- trical conductivity showed a plateau above 13 kHz. It is also observed that the dielectric properties of wet samples increase by several orders of magnitude compared to dry samples. V C 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 00, 000–000 KEYWORDS: AC specific electrical conductivity; effective dielec- tric permeability; multipurpose nonwoven fabrics; sorption properties; viscose/polypropylene INTRODUCTION Nonwoven fabrics are used in a wide range of consumer and industrial products with diverse properties, including wipes and different cleaning products, absorbent hygiene and personal care products, apparel, home furnish- ings, healthcare and surgical fabrics, construction, filtration, engineering, etc. 1 Advantages of cleaning products made of nonwovens in regard to the other textiles were essentially based on the following: high water absorption, water reten- tion, and dirt retention capacity, high cleaning performance coupled with a low fabrics weight, good hygienic characteris- tics, good self-cleaning properties, enhanced absorbency due to capillary forces and the large free inner volume. In addi- tion of this, product characteristics are settable within broad limits, thanks to a selection of suitable process parameters: choice of fiber and bonding agent, fabric weight, bonding technique, etc. 1 For multipurpose nonwoven fabric cleaning cloth, an important end-usage property is a low propensity to generate a static electricity, that is, good electro-physical properties. During the cleaning, the charge generated on the surface of cleaning cloth has a desirable effect because the material attracts and holds soils (dust, pollen, allergens) entrapped in the matrix of the nonwoven fabrics. 2 On the other hand, static electrical charges built up on the surface during the cleaning can have a negative effect because charge can be suddenly discharged in form of the spark and cause: an unpleasant shock of weak intensity on skin, the risk of fire or explosion in hazardous environments, or dam- age of sensitive electronic circuits and components. 3 There- fore, it is important to properly evaluate electro-physical properties of mentioned nonwoven products. Electro-physical properties of textile material are depending on several factors, both internal (related to the material itself) such as fiber type, structure of the fabric, moisture content of material, as well as external factors such are tem- perature, air humidity, etc. 4 As it is known, sorption properties of material are one of the most important properties which influence processing and end use of material. Sorption properties of textile materials and thus nonwoven fabrics can be examined using various methods for determining water absorptive capacity, 5 water retention value, 6,7 wetting time, 8,9 vertical wicking rate, 10,11 and other methods. From the literature is evident that the molecular structure (chemical structure, degree of polymeri- sation, molecular mass) and supramolecular structure (degree of crystallinity, molecular orientation, amorphous V C 2018 Wiley Periodicals, Inc. JOURNAL OF POLYMER SCIENCE, PART B: POLYMER PHYSICS 2018, 00, 000–000 1 JOURNAL OF POLYMER SCIENCE WWW.POLYMERPHYSICS.ORG FULL PAPER