Adsorption behavior of water soluble polymers with lower critical solution temperature

Abstract

The adsorption behavior of hydroxylpropyl cellulose (HPC), ethyl hydroxylethyl cellulose (EHEC) and poly-vinylalcohol (PVA) polymers, which have a lower critical solution temperature (LCST), have been studied in comparison with the behavior of hydroxylethyl cellulose (HEC) with no LCST. The saturated amount of adsorption (As) for the polymers with LCST depended significantly on the adsorption temperature and theAs, e. g., for HPC obtained at the LCST, the amount was 1.5 times as large as the value at room temperature. The highAs values obtained at the LCST were maintained over a long period at room temperature, and the dense adsorption layer formed on the latex particles at the LCST showed a strong protective action against flocculation. Furthermore, the effect of the surface nature of the adsorbent on the polymer adsorption at the LCST has been investigated using six kinds of synthetic latices with different surface natures. It was found that the hydrophobic interaction between the polymer and the adsorbent plays an important role in inducing the adsorption, and the trend of increasing the hydrophilic character of the latex surface prevents the formation of the adsorption layer of the polymer.