F. Mikes et al., FLUORESCENCE STUDY OF THE KINETICS OF ALKALI COUNTERION TRANSFER FROMA CARBOXYLIC IONOMER TO A POLYMER CARRYING SULFONIC-ACID SUBSTITUENTS, Macromolecules, 27(22), 1994, pp. 6577-6580
Copolymers of butyl methacrylate (BMA) with 3-(methacryloylamino)-2-na
phthoic acid (MANA) were neutralized with lithium methoxide, sodium me
thoxide, and cesium hydroxide. The counterion transfer from these copo
lymers to a BMA copolymer with [(2-(acryloylamino)prop-2-yl]methanesul
fonic acid (APMS) was monitored by the fluorescence change in a stoppe
d-flow apparatus in which solutions with equivalent concentrations of
MANA and APMS residues were mixed. The half-life of this transport was
17 times smaller in dioxane than in toluene and increased with a decr
easing size of the counterion. The apparent rate constant increased wi
th the progress of the ion transfer, which was interpreted as due tb a
decreasing ion-pair dimerization. The half-life of the process decrea
sed much more rapidly with an increasing concentration of the interact
ing copolymers than expected for second-order kinetics. Addition of po
ly(butyl methacrylate) had no significant effect on the rate of counte
rion transfer from BMA/MANA to the BMA/APMS copolymer.