There is no investigated report on the stable intermolecular aggregate of polysoaps in the aqueous solution. Authors prepared three anionic polysoaps (potassium salt of maleic anhydride and cetylvinyl ether copolymer) which had the molecular weights of 60.2×10
4 (
P-1), 40.8×10
4 (
P-2), and 6.3×10
4 (
P-3), and with which the following results were obtained concerning the aqueous polysoap solutions by means of light scattering.
(1) It is known that a polysoap simultaneously forms intermolecular aggregates besides the intramolecular micelles. Authors found out on additional fact that the molecular weight of the polysoaps gives a great influence upon the intermolecular aggregation. Namely, intermolecul araggregation increased with the decrease of the molecular weight of the polysoaps.
These three polysoaps have molecular weight distributions individually, therefore, some equal molecular sire of polysoap species overlaps each other. From this point of view, the lower molecular species of
P-1 would intermolecularly aggregate. The interpretation may necessarily mean the probability that the
P-1 molecules are degraded while the saponification reaction from the parent copolymer, and the lower species degraded from
P-1 aggregate each other. From this reason the observed M
w, would agree with the calculated value.
(2) From the extension (
r) of polysoap molecule per monosoap-unit, the large intermolecular aggregates of
P-2 and
P-3 seem to contract more than that of
P-1.
(3) As regards to the effect of temperature (from room temperature to 70°C) on the
r values of the polysoaps, the
P-1 molecule seems to expand with raise in the temperature owing to the increase of electrostatic repulsive force among charged heads, and also seems to contract reversibly to some extent with cooling down to room temperature, while either
P-2 or
P-3 is less temperature sensitive. Authors could understand this result by postulating an
interpenetrating structure of
P-2 and
P-3, in which a considerable part of charged heads of the polysoap molecules is buried in the interior part of the aggregate, thereby, a small part of the charges on an outer shell of the aggregate affect the
r, as was reported elsewhere.
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