SYNTHESIS AND PROPERTIES OF POLYAMPHOLYTES PREPARED IN MICROEMULSIONS

A series of polyampholytes of sodium 2-acrylamido-2-methylpropanesulfonate (NaAMPS) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MADQUAT) has been synthesized by polymerization in microemulsions. The reaction products are stable inverse latexes consisting of high molecular weight copolymers entrapped in water droplets of small size (d almost-equal-to 80 nm) and dispersed in an isoparaffinic oil. The optimization of the formulation was by a selection procedure based on the hydrophile-lipophile balance of the emulsfiers and solubility parameters of the different components. Both ionomers play an important role in the formulation owing to their amphiphilic and electrolyte characters. Reactivity parameter studies yield r(A) and r(M) values of 0.81 and 1.97 for NaAMPS and MADQUAT, respectively. The properties of polyampholytes in pure water and in salt solutions were investigated by turbidimetry and viscometry experiments. The results are compared with the recently developed theory of Higgs and Joanny (J. Chem. Phys. 94, 1543 (1991)).