Time dependence of the aggregation of star-shaped poly(2-isopropyl-2-oxazolines) in aqueous solutions

Abstract

The paper concerns the analysis of time teq required to equilibrium state achievement in aqueous solutions of star-shaped poly(2-isopropyl-2-oxazolines) (PiPrOx) after changing temperature. The discussed data were obtained for PiPrOx differing in arm number and length. For all samples, high teq values, half an hour at least, were obtained because of rather high intramolecular density. The dependence teq on temperature displayed maximum near the phase separation beginning due to the aggregate growth and redistribution of scattering particles. The maximum times teq increased symbatically with arm number and length. The higher energy of the hydrogen bond formed by deuterium isotope leads to the growth of the teq values as compared to solutions in H2O.