The kinetics of the heterogeneous hydrolysis of poly(vinyl formate) and of poly(vinyl formate‐co‐stearate)

Abstract

AbstractThe rate of hydrolysis of formate and stearate segments from poly(vinyl formate) and from poly(vinyl formate‐co‐stearate) suspended in dilute aqueous hydrochloric acid was studied. Evidence was presented to show that the hydrolysis follows pseudo‐first‐order kinetics. The Arrhenius constants and the entropies and free energies of activation for the hydrolysis of formate and stearate groups from copolymers containing 0, 3, 5, and 10 mole‐% vinyl stearate were calculated from the partially reduced reaction rate constants at three temperatures. For the hydrolysis of formate segments, ΔS‡ is markedly affected by the stearate content, whereas the variation in ΔF‡ is small. Variations in vinyl formate content have smaller effects on the thermodynamic constants of the activated complex for the hydrolysis of the stearate segments. At approximately 95°C., some anomalous kinetic behavior was observed.