Long Branched-Chain Amphiphilic Copolymers: Synthesis, Properties and Application in Heavy Oil Recovery

A series of water-soluble long branched-chain amphiphilic copolymers, AAGASs, were synthesized and applied in the enhanced oil recovery of heavy oil. Hydrophobically associating water-soluble copolymers (AAGs) with an epoxy group were first synthesized by free-radical copolymerization of acrylamide (AM) and sodium 2-acrylamido-2-methylpropanesulfonic acid with glycidyl methacrylate. An amino-terminated amphiphilic copolymer (AS-N) was also prepared with AM and sodium 4-styrenesulfonate via chain transfer polymerization. AAGASs were then obtained by the chain-extending reaction between the epoxy groups of the AAG and amino group of the AS-N. Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, static light scattering, and thermogravimetric analysis measurements were performed to determine the polymer structures and properties. Shear viscosity, surface tension, and interfacial tension were also investigated to understand the oil displacement mechanism of AAGAS solutions. The ...