Temperature dependence of viscosities and potentiometric titration behavior of aqueous poly(acrylic acid) and poly(methacrylic acid) solutions

Abstract

The viscosities of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA) have beenmeasured in aqueous 0.25 M NaCl solutions at 5, 15, 25, 35, and 45ŶC as a function of various degrees of neutralization. The potentiometric titration data for these polycarboxylic acidsin water at 5, 25, and 45ŶC are also reported. Both results indicate that the compact conformation of PMA at low degree of dissociation is more stabilized at lower temperatures. The origin of the hydrophobic interaction has been discussed and it has been suggested that any changeof water structure around hydrophobic groups is not required to account for the pH-induced conformational transition of PMA. © 1993, The Society of Polymer Science, Japan. All rights reserved.