Kinetics of polyether polyols–diisocyanate reactions

摘要

AbstractThe reaction rates for the uncatalyzed as well as the dibutyltin dilaurate‐catalyzed reactions between polyether polyols and tolylene diisocyanate (80/20 mixture of 2,4 and 2,6 isomers) are reported. Titration and infrared absorption methods were used for the determination of the residual isocyanate content, to follow the progress of the reactions. At equivalent reactant concentrations, the rate constants were found to be essentially independent of the chain length and the functionality of the polyether polyols studied. The reaction rates of polyether polyols containing terminal primary hydroxyl groups (e.g., Pluronic polyols) were greater than those of polyols with secondary hydroxyl groups and were greatly accelerated in the presence of the tin catalys