Dynamics of Surface-Adsorbed Polyacrylates.

摘要

The dynamics of poly(isopropyl acrylate) and poly(ethyl acrylate) have been studied by solid-state deuterium NMR. The polymers were specifically labelled in the methine polition and consequently the spectra are influenced directly by the backbone motion of the polymers. We have compared the deuterium NMR lineshapes of the two polymers in bulk. For poly(ethyl acrylate) we find that near and below Tg, a one component rigid spectrum is obtained. About 20 C above Tg, a two component spectrum is found with the intensity of the more mobile component increasing with temperature. By Tg + 50 the more mobile component dominates the spectrum. Comparison of the surface-bound and bulk poly(isopropyl acrylate) suggests that the surface bound materials are more constrained. Keywords: Molecular motion; Surfaces; Interfacial dynamics; Deuterium NMR; Adsorption. (jes)