Abstract
Physical properties, such as thermal and dielectric characteristics, of some aromatic polyimides which contain methylene units have been investigated. The results indicated that the polymers were highly thermostable with decomposition temperature over 450°C and low dielectric constants. The thermogravimetrical values processed by differential method Freeman-Caroll showed that the activation energies and reaction orders are lower in air than in nitrogen. Keywords: methylene units, polyimides, thermal characterization, activation energy, dielectric constants