A series of poly(urethane)s (PUs) based on diphenyl-silane or -germane and oxyphenyl units were synthesized by polycondesation of 4-[4-[9-[4-(4-aminophenoxy)-3-methyl-phenyl]fluoren-9-yl]-2-methyl-phenoxy]aniline (3) and four bis(chloroformate)s (IIV). These monomers were prepared and characterized in previous works. The best conditions for the polymerization reactions were investigated by a kinetic study. Also, a selection of the best solvent for the reaction was developed. Polymers were characterized by IR and H-1, C-13, and Si-29-NMR spectroscopy and the results were in agreement with the proposed structures. Poly(urethane)s showed inherent viscosity values between 0.12 and 0.31 dL/g, indicative of low molecular weight species, probably of oligomeric nature. The glass transition temperature (T-g) values were observed in the 127-168 degrees C range by DSC analysis. Thermal decomposition temperature (TDT10%) values were above 300 degrees C. All PUs showed good transparency in the visible region (>80% at 350 nm) due to the incorporation of the bulky monomer (fluorene) and oxyether linkages. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012