Synthesis and characterization of oligomeric silsesquioxane with pendent carboxylic acid groups

An oligomeric silsesquioxane with pendent carboxylic acid groups and with supposedly ladder structure was prepared by preaminolysis process followed by the controlled hydrolysis of pendent ester groups. A variety of characterization techniques including 1H-NMR, 29Si-NMR, FTIR, vapour pressure osmosis, X-ray diffraction, and DSC demonstrated the structure of the final product. The resulting oligomer exhibits excellent film-formability thanks to the formation of hydrogen-bonded network between the pendent carboxylic acid groups even though its molecular weight is low, which predicts its direct usage as coatings for a variety of purposes.