Self Diffusion in PMMA Solutions
In this paper the authors describe how Pulsed-Field Gradient, Spin-Echo Nuclear Magnetic Resonance (PFGSE method) can be used to measure the molecular weight of polydisperse polymer samples. The PFGSE NMR method has already been used to measure the self-diffusion coefficients of polymer molecules in solution for a variety of systems. The results of these studies illustrate the usefulness of the technique. In some of these previous experiments the effects of polydispersity of the polymer or additives were noted; however, to the best of the authors' knowledge this is the first time that the PFGSE experiment has been used to measure molecular weights of polydisperse polymers. Poly(methyl methacrylate) is the polymer chosen for this study. It lends itself to the NMR diffusion experiment because the proton spectrum has a narrow resolved peak from the methoxy resonance. The authors report the diffusion behavior and scaling law for 5 wt% solutions of PMMA in acetontrile-d3 at 40 degree C. This data is then used to extract molecular weight data for polydisperse systems of PMMA.
F. D. Blum and T. L. Maver, "Self Diffusion in PMMA Solutions," Royal Australian Chemical Institute, Jan 1985.
Article - Conference proceedings
© 1985 Royal Australian Chemical Institute, All rights reserved.