Phenyl methacrylate and p-tolyl methacrylate were synthesized by starting directly from methacrylic acid and the corresponding phenols. Polymer-analogous esterification on poly [ethylene-co-(acrylic acid)] (PEAA) was performed with phenol, p-methoxyphenol, and 2,4,6-trimethylphenol. The synthesized compounds were characterized by FT-IR and H-1 NMR measurements. The esterification reactions were performed under solvent-free conditions using an acid catalyst under microwave irradiation and in an oil-bath, for comparison. It was shown that MW irradiation effectively promotes the esterification especially on the polymeric system. Differential scanning calorimetry was employed to study the thermal behavior of modified and unmodified PEAA. One pot reaction and reaction time within minutes are the main advantages of the MW method.