Solubilization properties ofN-substituted amphiphilic acrylamide copolymers

Abstract

Amphiphilic copolymers of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) and dodecylmethacrylamide (DodMAAm) were synthesized. The ratio of the reduced viscosities of these copolymers in water and in 0.2 mol/L NaCl solution shows that these copolymers containing from 50 to 66 mol % of DodMAAm have a relatively small and constant hydrodynamic size. Viscometric and static light scattering measurements indicated that the copolymers shrinked and intermolecularly associated, forming interchain aggregates in water through hydrophobic interactions. These copolymers solubilize dl-␣-tocopherol acetate, giving a transparent solution; but the solution became turbid in a month due to increasing intermolecular association. To suppress this excess intermolecular association, polymers with four different crosslinking ratios were synthesized. The polymer of a crosslinking ratio of 0.5 mol % showed a strong solubilization property, resulting in transparent solution with an improved stability. The fluorescence spectra of pyrene in the polymer solution proved that these copolymers could form strong hydrophobic domains, which solubilize a hydrophobic compound, in less than 30 w/w % ethanol solution. These copolymers could have an excellent function of sustained release of perfume as a novel function.

Study on the rheological behavior of the hydrophobically modified hydroxyethyl cellulose with 1,2‐epoxyhexadecane*

“…Above C *, the intermolecular associating dominates. Wide‐range dynamic crosslinking molecular networks form via nodes of hydrophobic microdomains, which significantly increases the hydrodynamic volume and leads to the sharp ascending of the apparent viscosity 4…”

“…The supramolecular aggregation networks were destroyed under shear application resulting in the decrease of the hydrodynamic volume and the apparent viscosity. On the other hand, the entanglement of the molecules and the molecules in the state of intramolecule associations gradually extended, orientated, and the hydrophobic alkanes associated with each other under a certain shear rate leading to the increase of the hydrodynamic volume and the apparent viscosity 4. Therefore, this kind of polymer displayed very complex rheological behaviors.…”

Preparations and properties of thermosensitive terpolymers of N‐isopropylacrylamide, sodium 2‐acrylamido‐2‐methyl‐propanesuphonate, and N‐tert‐butylacrylamide

“…Durmaz and Okay17 synthesized a hydrogel based on acrylamide and AMPS and studied the characteristics. More studies on copolymers containing AMPS have been reported 18–21…”

Synthesis of diblock copolymers with cellulose derivatives. 3. Cellulose derivatives carrying a single pyrene group at the reducing-end and fluorescent studies of their self-assembly systems in aqueous NaOH solutions

“…The association system of amphiphilic copolymers has received much attention due to its high potential for biotechnological and pharmaceutical applications (Kataoka et al 1996). Various amphiphilic polymers were synthesized and their self-assembly systems in solutions have been extensively studied (Winnik et al , 1998Akiyoshi et al 1993;Guo et al 1996;Kataoka et al 1996;Thurmond et al 1996;Ding and Liu 1998;Kobayashi et al 1999). However, the synthetic method of diblock copolymers with cellulose and their self-assembly systems have not been clearly investigated.…”