The aim of the work is to prepare the halogenated methacrylate-based polymer nano-aluminum oxide (Al₂O₃) composites and to study the effect of incorporated nano-Al₂O₃ on morphological and thermal studies. A functional 2,4,6-tribromophenyl methacrylate-co-glycidyl methacrylate copolymer microspheres (poly(TBPMA-co-GMA); pTG) by emulsion solvent evaporation techniques, whereas (2,4,6-tribromophenyl methacrylate-co-glycidyl methacrylate)-Al₂O₃ nanocomposites (pTG-Al₂O₃ nanocomposites) were prepared by solution mixing techniques. The pTG and its Al₂O₃ nanocomposites were structurally characterized by Fourier transform infrared (FTIR) spectroscopy. Thermal studies of pTG and its Al₂O₃ nanocomposites were carried out by thermogravimetric analysis and differential scanning calorimetry . The molecular weight of the pTG was determined by gel permeation chromatography. The size distribution and morphology of the pTG and its Al₂O₃ nanocomposites were determined by scanning electron microscopy (SEM). The FTIR results reveal that there is no significant interaction between the polymer matrix and Al₂O₃ nanoparticle. The significant increase in the initial decomposition temperature and glass transition temperature of pTG-Al₂O₃ nanocomposites compared to its polymer was due to the incorporation of nano-Al₂O₃ in the polymer matrix. The SEM observation provides the information about the morphological changes that arise in polymer matrix due to the incorporation of nano-Al₂O₃.