LASER-EXCITED RAMAN STUDIES OF CONFORMATIONAL TRANSITION OF SYNDIOTACTIC POLYMETHACRYLIC ACID IN WATER

The Raman spectra of syndiotactic polymethacrylic acid were investigated in the solid state, and in water solution as a function of neutralization. The Raman and infrared spectra of the solid polyacid indicate a helical conformation with a pitch of 3:1 or greater. The Raman spectra at various degrees of neutralization indicate progressive changes in C-COOH motions in a neutralization range from 0.1 to 0.4, superimposed on the expected changes occuring as a function of ionization. The changes from 0.1 to 0.4 neutralization can be explained in terms of the breakup of hydrophobic methyl-methyl interactions, but unlike the denaturization of globular proteins this transition is progressive, not cooperative. © 1969, American Chemical Society. All rights reserved.