The Absorption of Alcohol and Saline Solution by Carbopol Grafted with 2-Acrylamido-2-methylpropane Sulfonic Acid Prepared Through Ultrasonic Method

In recent years, there have been several studies on characterization and preparation of polymeric organogels and alcohol-absorbent organogels which are the subgroup of polymeric organogels. Considering the importance of sulfonic monomers to improve the absorption of alcoholic acrylic acid-based adsorbent gels, due to their ability to separate ionic groups in a low-dielectric solvent such as ethanol, and the use of carbopol in medical and pharmaceutical industries, in the present study, the alcohol-absorbent gels were prepared by grafting sulfonated monomer on the surface of carbopol particles.

Alcohol-absorbent gels were prepared by grafting sulfonated monomer through the ultrasonic method. The effect of monomer content on alcohol and saline solution absorbency was investigated through swelling measurement.

In samples with similar particle size, an increase in ionic monomer content increased the absorption of alcohol due to dissociation ability of sulfonic acid groups. For example, in a sample containing 75% ionic monomer, 13% increase in ethylene glycol adsorption and 27% increase in salt absorption were observed compared to that containing 25% ionic monomer. The polymer chains resulting from the grafting of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) on the carbopol particle surface helped to increase absorption under load because of retaining the consistency of the swollen samples. Glass transition temperature (Tg) of the prepared sample decreased by 48% compared to carbopol, because the side chains caused steric hindrance and negative charge on the grafted poly(AMPS) chains resulted in electrostatic repulsion. The study on the effect of physical parameters such as particle size on the alcohol absorbency showed that by increasing the particle size of the prepared samples, the absorption of alcohol dropped significantly because of reduction in the contact area of the particles with the solvent.