Hydrolysis kinetics of a sol-gel equilibrium yielding ladder-like polysilsesquioxanes

Abstract

An investigation into the hydrolysis kinetics of an aqueous base-catalyzed sol-gel reaction yielding ladder-like polysilsesquioxanes was studied using NMR. Under various variables of monomer concentration, water concentration, solvent type, and monomer type, the various effects on molecular weight and degree of condensation were elucidated. Moreover, the various rate orders and rate constants were calculated and compared with previous reports of the hydrolysis of organosilane precursors. Through this study we were able to ascertain the optimal conditions of hydrolysis-polycondensation for obtaining highly condensed, high molecular weight ladder like polysilsesquioxanes. (C) 2016 Elsevier B.V. All rights reserved.