Morphological Characterization of Blends of Metal-Sulfonated Poly(styrene) and a Methylated Poly(amide) by Solid State NMR

Published

January 1, 2000

Author(s)

David L. VanderHart, Y Feng, Charles C. Han, Robert A. Weiss

Abstract

Various blends of atactic, low-MW ({approximately} 4000), metal-sulfonated poly(styrene) (MSPS) and a higher-MW ({approximately} 25,000) poly(amide) (PA) were studied by solid-state ¹³C and proton NMR techniques which include multiple-pulse irradiation, cross-polarization, and magic angle spinning. This study is a preliminary investigation of the morphology of these MSPS(n)/PA blends (n = 2.3, 7.0 or 11.9 mole % sulfonate) as functions of blend composition and sulfonation level. Unsulfonated PS and PA are incompatible and phase separate. Decoration with sulfonate groups promotes mixing of the blend components owing to strong, polar metal-sulfonate/amide interactions. Metal ions used were divalent Zn (diamagnetic) and Cu (paramagnetic), the latter ions having a significant influence on the protons. The PA, N,N'-dimethylethylene sebacamide, was N-methylated to weaken intermolecular interactions within the PA and to promote mixing. Pure PA is semicrystalline and intimate mixing prevents PA crystallization. ¹³C CPMAS spectra were used to assay PA crystallinity. The stability of the blend morphology in the presence of water was also studied since water is expected to modify or compete with the polar interactions of the blend. Many of the experiments performed relied, for their interpretation, on the phenomenon of proton spin diffusion.

Citation

Macromolecules

Volume

33(6)

Pub Type

Journals

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Keywords

blend, crystallinity, morphology, NMR, poly(amide), poly(styrene), solid state, spin diffusion

Citation

VanderHart, D. , Feng, Y. , Han, C. and Weiss, R. (2000), Morphological Characterization of Blends of Metal-Sulfonated Poly(styrene) and a Methylated Poly(amide) by Solid State NMR, Macromolecules, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851499 (Accessed April 25, 2024)