In this study, macroporous composites of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) i.e. poly(GMA-co-EGDMA) and clay were prepared by radical suspension copolymerization. The composites with either raw (S(0)) or acid-modified clay (S(A)) were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric (TG) and textural analysis. The morphological, textural and thermal properties of the composite with raw clay (CP-S(0)) differed slightly from those of the copolymer (CP), with exception of the thermal stability expressed in the shifting of the initial degradation temperature from 125 degrees C for CP to 210 degrees C for CP-S(0). On the other hand, composite with modified clay (CP-S(A)) was a material with significantly changed morphology, porous structure parameters and a qualitatively different thermal behavior in comparison to CP and CP-S(0). CP-S(A) had mass residue, after heating at 6000 degrees C, three times higher than the amount of S(A) introduced into the reaction system. This indicates a different manner of incorporation of S(A), compared to S(0), into the composite. Both the obtained composites retained their macroporosity and might be used in all applications that involve macroporous copolymers and, due to the altered thermal properties, their application may be extended. (C) 2011 Elsevier B.V. All rights reserved.