Starlike Branched Polyacrylamides by RAFT Polymerization—Part I: Synthesis and Characterization

Abstract

Starlike branched polyacrylamides (SB-PAMs) were synthesized using reversible addition–fragmentation chain transfer copolymerization of acrylamide (AM) and N,N′-methylenebis(acrylamide) (BisAM) in the presence of 3-(((benzylthio) carbonothioyl)thio)propanoic acid as a chain transfer agent, followed by chain extension with AM. The amount of incorporated BisAM in the core and the amount of AM during chain extension have been systematically varied. Core structures were achieved by incorporation of total monomer ratios [BisAM]/[AM] ranging from 0.010 to 0.143. The obtained macromolecular chain transfer agents had weight average molecular weights in the range of (2.2–7.8) × 103 Da and polydispersity indices between 1.2 and 15.1. Kinetic experiments were performed to investigate the extent of control of polymerization. Finally, the expansion of the core structures by chain-extension polymerization resulted in the successful preparation of high molecular weight SB-PAMs with apparent molecular weights ranging from 19 to 1250 kDa.

Development of Novel Star-Like Branched-Chain Acrylamide (AM)-Sodium Styrene Sulfonate (SSS) Copolymers for Heavy Oil Emulsion Viscosity Reduction and Its Potential Application in Enhanced Oil Recovery

“…The branched polymer was designed for maximum branching and a balance of water solubility according to a procedure in the literature. 16 We believe that the higher the branching degree, the higher the heavy oil viscosity reduction efficiency. The average molecular weight (M n ) of the SB polymer is determined by GPC analysis between 5.5 and 22 × 10 4 g/mol and polydispersity index (PDI) between 1.57 and 6.95 (Table 1).…”

Where is research on fossil fuels going in times of climate change? A perspective on chemical enhanced oil recovery

“…[30,50] Another non-standard approach can be based on playing with polymer architecture (hyperbranched vs linear), to tune the viscoelastic properties. [51,52] Particularly interesting is also the use of thermoviscosifying polymers for high-temperature reservoirs. [30,[53][54][55] This approach introduces the use of "smart" polymers, able to display the desired properties (in this case an increase in viscosity), only when and where required, at the high temperature of the reservoir.…”

Water-Soluble Branched Polyacrylamides Prepared by UV-Initiated Polymerization Using a Novel Kind of Water-Soluble Macromolecular Photoinitiator

“…Hence, facile, highly efficient, and cost-effective preparation of branched PAMs with a specific structure and unique properties has become a hot topic and has attracted intensive research interest. 10,22 Generally, the grafting-from strategy is an efficient route for the preparation of branched polymers. 23 It has been demonstrated that PAM polymers with precise chemical composition, well-defined molar mass, and complex structure were successfully synthesized using the grafting-from approach combined with reversible-deactivation radical polymerization methods, such as atom transfer radical polymerization (ATRP) and reversible addition−fragmentation chain transfer (RAFT) polymerization.…”

“…In view of the aforementioned discussion, the distinctive rheology characteristics endow the branched PAMs with wide potential applications in various fields. Hence, facile, highly efficient, and cost-effective preparation of branched PAMs with a specific structure and unique properties has become a hot topic and has attracted intensive research interest. , …”