Synthesis of a novel double-tailed hydrophobically associating polymer for ultra-high salinity resistance

Because of the unique double-tailed hydrophobic monomer, the hydrophobic association and H-bond interaction were enhanced to get a hydrophobically associating polymer with evident salt thickening ability and shear thickening ability. • A new synthetic strategy for preparing a double-tailed hydrophobic monomer is proposed. • Evident salt thickening, shear thickening and thermal thickening phenomena are observed. • The polymer has the potential for improving foam properties and proppant suspension ability. A new strategy for preparing double-tailed hydrophobic monomer, N, N-diethyldodecanamide methacrylamide (DEDAMA), was designed. Then, the synthesized monomer was used to prepare the hydrophobic associated polymer (PAM/AA/DEDAMA) to improve salt resistance under ultra-high salinity conditions. Viscosity and rheological behavior were evaluated. The results showed that the viscosity of the polymer in saline water was higher than that in fresh water, indicating an evident salt thickening ability. An obvious shear thickening phenomenon was observed in rheological experiments, showing strong interactions among the polymer chains. We attributed the observed properties to the unbroken hydration shell and spatial network, which can be observed in the scanning electron microscopy images. Based on these properties, the polymer can be used to improve proppant suspension ability and foam stability at ultra-high salinity, indicating its potential for application in the petroleum industry.