David R. Fagerburg

Investigation of the reaction of some unsaturated dicarboxylic acid anhydrides with cyclic carbonates

Abstract This work reports attempts to extend to unsaturated anhydrides the rapid reaction of dicarboxylic acid anhydrides with ethylene carbonate to form polymer directly. The reaction of unsaturated diacid anhydrides with two cyclic carbonates, ethylene and propylene carbonate, leads to gelled products whenever the anhydride is capable of Michael addition, while an anhydride without such unsaturation gave linear polymer in- stead. The GC/MS results, along with efforts to trap radical reactions, support Michael addition as an explanation of gelation in these systems.

Reaction Kinetics of the Model Reaction of Benzoic Acid with Ethylene Carbonate

Abstract As a model for several polymer-related reactions, we have reexamined the reaction kinetics of benzoic acid with ethylene carbonate in which various quaternary ammonium salts were used as catalysts. The salt anion appeared to have little or no effect on the rate of reaction. At a 1:1 mole ratio of acid to carbonate, the reaction was zero-order to about 95% reaction. With tetraethyl-ammonium hydroxide catalyst at 0.4 mol% (based on carbonate moles), the activation energy was 20.8 kcal/mol with a preexponential factor of In A = 17.1 (activation entropy of -26 cal/deg). The activation energy for decomposition of the carbonate alone was 33.0 kcal/mol with a preexponential factor of In A = 27.3. This rules out previously suggested mechanisms that essentially involved decomposition of the carbonate prior to esterification. The proposed mechanism for the reaction involves the attack of the quaternary salt carboxylate on the methylene carbon of the carbonate. The attack causes ring opening and is followed...