SYNTHESES AND SPECTROSCOPIC PH TITRATIONS OF NAPHTHOL-LABELED POLY(METHACRYLIC ACID)S

Poly(methacrylic acid) (PMA) and poly(acrylamide) (PAAm) with a small mole fraction of naphthol (NpOH) residues were prepared by polymerizat ion of methacrylic acid or acrylamide with three position isomers, met hacryloylaminonaphthol. The substiluent effect on the apparent pK valu es (pK(obsd)) determined by spectroscopic pH titrations in aqueous sol ution, was observed for the NpOH-Iabeled PAAm. The electrostatic surfa ce potential (psi) for PMA was calculated From the difference in the p K(obsd) values for the labeled PMA and PAAm. The obtained psi value de creased as the spacing between the OH moiety and the polymer main chai n increased. This clearly indicates that tile psi value is a sensitive function of the distance from the polyion surface.