Static Secondary Ion Mass Spectrometry for Study of Surface Hydrolysis of Poly(felt-butyl methacrylate)

Recent research has demonstrated that static SIMS provides an important complement to ESCA for the analysis of polymer surfaces. There are cases where ESCA samples deep enough In amorphous polymers to yield compositional data equivalent to bulk values. In the present study static SIMS is used to analyze a system which could not be followed by routine ESCA experiments: the acid/base catalyzed hydrolysis of the tert-butyl ester function In poly(tert-butyl methacrylate). Exposure of solvent cast polymer films to aqueous solutions at various pHs shows that for mild acidic and basic conditions, hydrolysis occurs to a higher degree than for exposure to neutral solutions, which follows from the catalytic effect of the nonneutral conditions. At very high and low pHs degradation of the polymer occurred too rapidly to monitor. This study demonstrates the feasibility of using static SIMS to study chemical reactions on polymers, especially for cases in which ESCA Is not useful.