Hyperbranched Star\nMonomer: A New Strategy to Improve\nHPAM in Harsh Environments

The thickening properties of water-soluble polymers,\nsuch as partially\nhydrolyzed polyacrylamide (HPAM), are generally compromised under\nhigh salinity and temperature conditions. The resulting loss of viscosity\nlimits their applications or necessitates the use of large quantities\nof polymers, making some processes economically unviable. In this\nstudy, we present the design and synthesis of a new star macromonomer\ncapable of minimizing the viscosity loss of HPAM in harsh environments.\nThe macromonomer was designed and prepared by using a Boltorn H30\ncore and a PEGMA<sup>500</sup> shell. The incorporation of a vinyl\ngroup into the structure allowed this star system to be used as a\nter-monomer in HPAM synthesis. The resulting ter-polymer was characterized\nby NMR and SEC. Rheological studies confirmed the potentiality of\nthe macromonomer as an HPAM viscosity enhancer due to interactions\nbetween the hyperbranched macromonomers. This novel macromonomer could\nbe explored in various applications requiring thickening aqueous systems\nin harsh environments, such as improved oil recovery processes with\ngreater sustainability, among others.