Effect of plasticization by amines on the physical properties of an acidic styrene copolymer

Abstract

Abstract The dynamic mechanical properties of partly sulfonated (8.1 mole%) polystyrene were investigated at a frequency of ca. 1 Hz, following neutralization with various low molecular weight flexible and rigid amines. IR spectroscopic evidence suggested that the protonated amine units were possibly H‐bonded to the sulfonate anion. Neutralization with flexible amines was found to result in a decrease in the glass transition temperature T g by an amount proportional to the number of carbon atoms in the amine, while neutralization with rigid amines was found to result in an increase in T g . It was also observed that the amines were more miscible with the sulfonated material than with polystyrene. It was concluded that the changes in properties observed upon neutralization are similar to those expected from a graft.