Ultrasonic enhancement of the rheological properties of poly (acryl amide with 3-sulpho-propyl acrylate) microgel achieved via precipitation polymerization

Poly(acryl amide-co-3-sulpho-propyl acrylate) (poly(AM-TSPA)) microgels crosslinked by trimethylolpropane triacrylate (TMPTA) were prepared by free radical precipitation polymerization at 60 °C with the aid of ultrasonic illumination. 2,2'-azobisisobutyronitrile (AIBN) was used as the initiator. The experimental results showed that the efficiency of ultrasound treatment for synthesizing poly(AM-TSPA) microgel polymers was dependent on factors such as frequency, intensity, duration, temperature, and fundamental properties of microgel like macromolecular construction. By choosing appropriate ultrasound parameters (frequency, amplitude, temperature, time, and concentration of the inherent characteristics of each monomer), the ultrasound treatment could increase the viscosity of poly(AM-TSPA) and facilitate normal pseudo-plastic and shear thinning activity as well. Furthermore, under 120 W ultrasonic irradiation, maximal values of Gʹ and Gʺ were achieved by the increased elasticity of poly(AM-TSPA).