Microparticles composed of (meth)acrylic acid, potassium (meth)acrylate, and trifunctional pentaerythritol were prepared using a thermally initiated free radical precipitation polymerization in ethyl acetate. The particle synthesis method was investigated, and the structure and morphology of the microparticles was evaluated using Fourier transform infrared spectroscopy and scanning electron microscopy. Results indicate that the physicochemical properties of the microparticles are dependent on the crosslinking ratio and type of carboxylic acid monomer employed in the polymerizations. The glass transition temperature behavior is significantly affected by the monomer type and the amount of crosslinking agent employed. The swelling dynamics of the microparticles are also pH, monomer, and crosslinking ratio dependent.