The synthesis and characterization of diethyl oxomalonate-, glycerol-, and nitroglycerin-functionalized polystyrene (DPS, GPS, and NGPS) from polystyrene (PS) by the chemical-modification route were explored. DPS was synthesized by the Friedel-Crafts acylation of PS with diethyl oxomalonate in the presence of SnCl4 by a batchwise-addition process. Proton NMR studies indicate that the acylation was essentially quantitative. IR spectroscopy was additionally used to confirm the transformation. The reduction of DPS was carried out using various reduction agents and reaction conditions. The sodium hydride reduction in tetrahydrofuran resulted in a quantitative conversion to GPS as estimated by H-1 NMR spectroscopy. Treatment of GPS with a nitrating mixture of nitric and sulfuric acids results in the formation of NGPS. All the polymers were characterized using gel permeation chromatography, IR, UV, H-1 spectroscopic techniques, pyrolysis-mass spectrometry, and thermogravimetric analysis. This is the first investigation on the syntheses of DPS, GPS, and NGPS. (C) 2001 John Wiley & Sons, Inc.