Reversible Addition–Fragmentation Chain-Transfer Polymerization of Amphiphilic Polycarboxybetaines and Their Molecular Interactions

Abstract

In this work, we report the first molecular weight-controlled amphiphilic polybetaine synthesis using various hydrocarbons via reversible addition−fragmentation chain-transfer (RAFT) polymerization. The experimental separation of the alkyl aminocrotonate tautomers, which has been the subject of debate, was completed for the first time. The enamine form of these tautomers was further used as a monomer for the RAFT polymerization of amphiphilic polycarboxybetaines. Self-assembly of the amphiphilic polycarboxybetaines showed micelle structures from spherical, rod-like to fractal in the aqueous media due to the competition between both electrostatic and hydrophobic forces. Hydrophobically dominant interactions among amphiphilic polycarboxybetaines and long-chain hydrocarbon alkane molecules were investigated to understand long-chain hydrocarbon alkane crystallization using alkane crystal deposition and viscosity experiments. Strong hydrophobic forces between poly(hexadecyl-grafted aminocrotonate−methacrylic acid) and long-chain hydrocarbon alkane molecules changed the surface properties of the long-chain hydrocarbon alkane nucleus and inhibited the growth of paraffin crystals.

P(DADMAAC‐co‐DMAA): Synthesis, thermal stability, and kinetics

“…In these applications, understanding of its kinetics is important for the large‐scale production of those polymers 14,15 . As usual, polymerization kinetics depends on many factors such as polymerization rate, initiator concentration, monomer concentration, and temperature 16‐19 . Production of polymer or copolymer with high yields also requires polymerization kinetics of the polmer 20 …”