The effect of microwave plasma on lightweight cotton fabric was investigated. N-2-plasma, O-2-plasma, and Ar-plasma were obtained using a microwave generator at 2.45 GHz under vacuum. The universal attenuated total reflectance-Fourier transform infrared (UATR-FTIR) instrument was used to monitor the changes created after N-2-, O-2-, and Ar-plasma treatments. The exposure of cotton fabrics to the plasma for 240 s with a microwave power of 500 W was sufficient to create active carbonyl groups, as shown by the presence of a peak around 1725 cm in the FTIR spectra of the treated cotton fabrics. Ar-plasma was found to generate more active groups than N-2- and O-2-Plasmas. The active centers created within the cellulose chains were used to initiate copolymerization reactions with vinyl monomers to impart hydrophobic character to lightweight cotton fabric. The efficiency of the grafting process and the presence of grafted monomers on fabric surface were confirmed using UATR-FTIR. Testing of treated fabric revealed that excellent water repellency was obtained. (C) 2004 Wiley Periodicals, Inc.