Copolymerization of 2-ethylhexylacrylate and styrene was performed in presence of benzoyl peroxide as initiator at varying concentrations of the comonomers in a microwave oven. Montmorillonite (MMT) clay was added with a view to prepare nanocomposites, which actually enhanced the water absorption capacity and pressure sensitive adhesive properties. The copolymer and its nanocomposite were characterized by Fourier Transform Infrared, 1H- and 13C-NMR, thermogravimetric-differential thermal analysis (TG-DTA), differential scanning calorimeter, scanning electron microscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The MMT layers were partially exfoliated/intercalated during the polymerization process as evident from the XRD and TEM observations. Their adhesive properties, water absorbancy, and biodegradability in different conditions were studied for their future applications. The monomer reactivity ratios were determined using Finemann-Ross and Kelen-Tudos method. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012