Abstract

Effect of catalysis on deblocking and cure reactions of phenol-blocked aliphatic diisocyanate adducts and pre-polymers were
investigated using CO2 evolution method and cure time studies, respectively. Completion of cure reaction of blocked aliphatic
diisocyanates and Terathane 2000 was confirmed by ATR spectroscopy. Tertiary amines and organotin compounds were used
as catalysts for the deblocking and cure reactions, and the organotin catalyst demonstrated better catalytic activity. However,
due to the synergistic effect, a combination of tertiary amine and organotin catalysts demonstrated superior catalytic activity
than individual ones. The influence of catalyst concentration on the cure reaction was also investigated. The lowest deblocking
temperature of 35°C was achieved in the case of unsubstituted phenol-blocked aliphatic diisocyanate pre-polymer in solution
state using a mixture of DBTDL and DABCO, and the cure time was found to be 25 min as it is an important factor for thermal
cure process need to be carried out at mild conditions.