Thickening properties and emulsification mechanisms of new derivatives of polysaccharide in aqueous solution 2. The effect of the substitution ratio of hydrophobic/hydrophilic moieties.
The thickening properties and association behavior of aqueous solutions of HHM-HEC (hydrophobically-hydrophilically modified hydroxyethyl cellulose) with various hydrophobic and hydrophilic substitution degrees were investigated. The HHM-HEC was used as an oil-in-water emulsifier and stable compositional regions were investigated as a function of polymer concentration and substitution degree. The viscosity of aqueous solutions of HHM-HEC increased drastically at lower concentration for HHM-HEC with a higher hydrophobic/hydrophilic substitution ratio. The intensity ratio of the first and third vibrational bands of pyrene (I(1)/I(3)) decreased with the increase of HHM-HEC concentration and the I(1)/I(3) reached a lower plateau at a lower concentration for HHM-HEC with a higher hydrophobic/hydrophilic substitution ratio. The concentration ranges of HHM-HEC solutions which stabilize O/W emulsions differ by the hydrophobic/hydrophilic substitution ratio. However the viscosity ranges of these HHM-HEC solutions were almost the same regardless of the hydrophobic/hydrophilic substitution ratio. At the suitable concentration range for emulsification, HHM-HEC networks have two properties: (1) oil particle retention capacity and (2) laxation which can trap emulsified particles.
Akiyama
Eri
E
Kao Corporation, Tokyo Research Lab., 2-1-3 Bunka, Sumidaku, Tokyo 131-8501, Japan. akiyama.eri@kao.co.jp
Yamamoto
Takamasa
T
Yago
Yuuko
Y
Hotta
Hajime
H
Ihara
Takeshi
T
Kitsuki
Tomohito
T