Solvent evaporation from Novolak solution was characterized by TGA and occurs in two distinct stages of solvent loss: an evaporation limiting stage (solvent determined) and a diffusion limfting stage (polymer determined) and is used to understand solvent retention mechanism during spin coating. Retained solvent content in Novolak films, as determined by gas chromatography and Fl-IA Spectrometry, is found to reduce the apparent Ig and increase the bulk dissolution rate of the novolak. Solvent distribution in the film, monftored as a function of depth by a reflectance FI-IR technique, is used to develop a Novolak dissolution model which characterizes both surface induction and bulk dissolution behaviour. 610
The dependence of the dissolution rates of phenolic resins on the base concentration of the developer can be described by a dimensionless equation based on a membrane model of novolak dissolution [J. P. Huang, T. K. Kwei, and A. Reiser, Macromolecules 22, 4106 (1989) and R. A. Arcus, Proc. SPIE 631, 124, (1986)]. The resin is characterized by a dissolution threshold c0, which is a limiting base concentration below which dissolution no longer occurs, by a scaling exponent n and by a membrane permeability Pr which refers to a developer of base concentration c = 2c0. Under these reference conditions all resins are in a corresponding state and dissolve with the same dimensionless rate of R/Pr = 0.5. The inhibition effect in an inhibitor/resin pair is represented by a plot of log(Ri/R0) against the inhibitor concentration in the resin matrix, where Ri is the rate of dissolution of the inhibited, R0 the rate of dissolution of the pure resin. The slope of this plot is independent of the inhibitor concentration over a reasonable concentration range and may be termed the inhibition factor and used as a measure of the inherent inhibition capability of the inhibitor in the resin. It is termed the inhibition factor. It is suggested that inhibition factors be compared in conditions where the pure resins dissolve at the same rate. In this study we have chosen a rate of 15 μm/min as the standard condition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.