Abstract
In this study, a thermally stable copolymer based on polyvinylpyrrolidone (PVP) and acrylamide (AM) was successfully synthesized via gamma irradiation. The polymerization proceeded via a free-radical mechanism, enabling the formation of a high-purity product without the use of chemical initiators. The optimal irradiation condition was determined to be a dose of 20 kGy for 7 h. The optimal polymerization conditions were achieved at a reaction time of 7.46 h and an AM monomer concentration of 19.92 wt%, yielding a maximum reaction efficiency of 85.77%. The physicochemical properties of the copolymer were characterized by FT-IR, SEM and TGA, confirming successful copolymer formation and excellent thermal stability with a decomposition temperature above 200 °C. The rheological behavior and thermal stability of the polymer solution were evaluated under simulated reservoir conditions. At a concentration of 0.3 wt%, the P(AM–PVP) solution exhibited a stable viscosity of approximately 5.86 cP and remained nearly unchanged after 30 days of thermal aging at 128 °C. These results demonstrate the potential of the gamma-irradiated PVP–AM copolymer for enhanced oil recovery in high-temperature, high-salinity offshore reservoirs.
