Hymatomelanic acids as polyelectrolytes. I. Viscometric and osmometric studies

The polyelectrolyte character of four natural and ten synthetic hymatomelanic acids, synthesized from possible monomers both in the presence and absence of catalysts, was established by means of viscosity measurements. Intrinsic viscosities were evaluated for the purpose of comparison. The number-average molecular weights of some typical natural and synthetic hymatomelanic acids were determined from osmotic pressure measurements. Using the Flory-Fox relationship in an approximate manner, the root-mean-square average end-to-end separations were also evaluated.