Rheokinetic and infrared spectroscopic study of the process of formation of an oligoimide

Abstract The results of rheokinetic and IR spectroscopic study of the process of synthesis of an oligoimide based on 4,4′-diphenylmethane diisocyanate and the dianhydride of 3,3′,4,4′-benzophenone tetracarboxylic acid are compared. Rise in the degree of conversion in time is described by a second order kinetic equation. Increase in the viscosity of the reaction system is determined both by rise in the MW of the oligomer formed and by change in the relaxational state of the system. A generalized expression is proposed for the rise in viscosity of the reaction mass.