were introduced, while protecting the reaction from the light. After all of the isocyanate groups were converted, as determined by FT-IR by the absence of the band at 2262 cm -1 , the flask was removed from the oil bath and cooled down to room temperature. The product was then precipitated into four-fold excess of ice-cold methanol three times and any residual solvent was evaporated under reduced pressure at 50 °C. The obtained product was a transparent, highly viscous, sticky, yellowish liquid. The same procedure was repeated for all catalysts, for both 2 and 4 mol% concentrations. The series of macromonomers synthesized with different catalysts are abbreviated as follows: PrDBTDL, PrBiNDE, PrBiHex, PrZnAc.