A polar ester-functionalized aliphatic polysulfone with an odd-number of linking carbon atoms possessing remarkable thermal stability, degrading at 100 degrees C above previously prepared polysulfones, was prepared in conjunction with the proposal of a novel concept for polar organic polymers. The synthesis involved polyaddition of vinyl sulfone and tert-butyl ethyl malonate in the presence of an amidine base and catalytic amount of water, followed by decarbo-tert-butoxylation. The polymers were characterized by infrared and nuclear magnetic resonance spectroscopies, elemental analysis, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. Characterization results compared well with model compounds. Poly-decarbo-tert-butoxylation was achieved by exposure to trifluoroacetic acid, followed by treatment with copper(I) oxide, affording a soluble polar polysulfone, which could be cast into homogeneous films.