Abstract
The interaction between polysoaps (potassium salt of maleic anhydride and cetylvinyl ether copolymer, the Mw of P-1=6.0 × 105 ; that of P-3=6 × 104) and monosoaps was examined in the aqueous solution by means of light scattering, viscosity, carbon black dispersing power, and specific conductance measurements. The authors investigated the changes of the above-mentioned properties of the polysoap solutions as the function of the added amount of potassium-fatty acid salt homologues (potassium palmitate (KP), laurate (KL), caprylate (KC), and acetate (KA)), when these fatty acid salts were added at a constant concentration levels of aqueous polysoap solutions.
(1) The apparent reduced intensity (R90), dissymmetry (Z), and relative viscosity (ηrel) of the polysoap solutions remarkably depend upon the alkyl chain length of potassium-fatty acid salts. Namely, R90, Z and ηrel decreased rapidly upon the addition of a trace amount of monosoaps (KP, KL, KC). This phenomenon may be attributed to the size reduction of the polysoaps due to the degradation of the intermolecular aggregate of the polysoaps. On the contrary, the R90 and the Z of the polysoap solutions decreased gradually, then, followed a slight increase in the trent upon the addition of KA. This behavior may be interpreted by postulating a salting-out effect of KA on the polysoap solutions.
(2) Either monosoap or carbon black seems to be adsorbed on the same site of the polysoap molecules (on the alkyl side chain of the polysoaps). Furthermore, the monosoap adsorption on the polysoaps is probably prior to the carbon black adsorption.
