1996 Volume 45 Issue 4 Pages 321-326
A model allophanate compound was prepared by reacting primary and secondary alcohols with excess di-isocyanate at a high temperature. This was then treated with butylamine (BA) and 1-(3-aminopropyl)-1, 1, 3, 3, 3-pentamethyl disiloxane (APDS). The resultant products were analysed by comparing their 13C-NMR spectra with the corresponding urethane compounds. These model compounds possessing uretidione and isocyanurate groups, which had been derived from diphenyl methanediisocyanate, were also treated with the above two amines. The progression of their reactions was determined by means of IR spectroscopy. As a result of the above experiments, it was found that the isocyanurate linkages were destroyed when treated with BA but not when APDS was applied. The other model compounds reacted with both amines. It is anticipated that the presence of isocyanurate linkages in polyurethane networks can be distinguished from allophanate linkages, and their respective volumes determined using the amine decomposition technique outlined above.
