SOLUTION AND RHEOLOGICAL PROPERTIES OF POLY(M-PHENYLENEISOPHTHALAMIDE) IN DIMETHYLACETAMIDE-LICL

An experimental study of the solution properties of poly(m‐phenyleneisophthalamide) (MPD‐I) in dimethylacetamide (DMA)/LiCl solutions is presented. Differential refractometry, light scattering photometry, dilute and concentrated solution viscometry, and normal stress experiments are reported and interpreted. This polymer in the concentration range investigated does not exhibit mesophase behavior in contrast to its para‐linked analog. Generally, it behaves as a flexible polymer molecule; however, its capacity to become a polyelectrolyte strongly influences its behavior in the presence of LiCl. MPD‐I is self‐associated when dissolved in pure DMA but dissociates in DMA/LiCl solvent systems. The Zimm plots of MPD‐I in DMA/LiCl solutions show distortion, probably due to polymer–salt interactions. Copyright © 1979 John Wiley & Sons, Inc.