KINETICS OF AMINE-CYCLIC ANHYDRIDE REACTIONS IN MODERATELY POLAR SOLUTIONS

The validity of extrapolating the reactivity of low molar mass compounds in solution to the polymer-analogous chemistry between polymer-bound functionality is investigated for the reaction of primary amines with cyclic anhydrides in the moderately polar solvents, anisole and tetraethyleneglycol dimethylether. The kinetics of amic-acid formation and imidization of polymeric and small molecule mixtures measured by Fourier-Transform Infrared Spectroscopy at near-ambient and elevated temperatures are compared. A significant decrease in both reaction rates is observed upon changing the primary amine from aliphatic to benzylic, benzylic to 1,2-diphenylethylamine, and 1,2-diphenylethylamine to polystyrene-bound 1,2-diphenylethylamine. Reasons for the influence of polymer-bound chemical functionality on the reaction rates for these amines are discussed. The imidization step is found to be rate limiting in the reaction of phthalic anhydride with benzylamine at the functional group concentrations reported (0.14M or less). (C) 1995 John Wiley and Sons, Inc.