The nanocomposites from conjugated linseed oil, acrylic acid, and divinylbenzene are synthesized using modified montmorillonite clay and characterized for thermal properties. The wide angle X‐ray diffraction results clearly show the distortion of the platy nanolayers of the nanofiller in the polymer matrix as the peak due to the clay disappears in the nanocomposite samples. The dynamic mechanical analysis results show the enhanced storage modulus and transition temperature compared with the pristine polymer. At the glass transition temperature, the storage modulus of nanocomposites is in the range of 17–79 MPa, whereas the pristine polymer shows a storage modulus of 2.1 MPa. The melting peak temperature ranges from 230 to 260°C, which is further confirmed by thermogravimetric analysis (TGA) results. The samples are stable up to 200°C and show a two‐stage degradation. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers