pH-Controlled Stereoregular Polymerization of Poly(methyl methacrylate) in Vesicle Membranes

Abstract

Here, we report a pH-controlled stereoregular polymerization of methyl methacrylate (MMA) inside the membrane of H20-COOH hyperbranched polymer vesicles using a common radical polymerization process. The vesicle size decreases from 745 to 214 nm with an increase of solution pH from 2.60 to 7.26, and the isotacticity of the obtained polymethyl methacrylates (PMMAs) is accordingly elevated from 9 to 35%. The obtained isotactic-rich PMMAs show a lower glass transition temperature depending on the isotacticity than the commercial random PMMAs. A mechanism study according to the in situ Fourier transform infrared measurements indicates that the control of polymer isotacticity results from the monomer conformation confined effect inside the thin vesicle membranes. The present study provides a new method to realize the preparation of isotactic polymers with the characteristics of facile synthesis, pH controllability, and a green polymerization process in aqueous solution as well as under mild reaction conditions of ambient temperature and pressure.

Synthesis and Aggregation Behavior of Hexameric Quaternary Ammonium Salt Surfactant Tz-6C12QC

“…The dimensions of the simulated box are as follows: L x = 100 Å, L y = 100 Å, and L z = 100 Å. The bead density of this system is 3 g/cm 3 , the time step is 100 fs, and the simulation time is 100 ns.…”

“…With the rapid development of the chemical industry, the demand for high-performance surfactants is increasing. Therefore, polysurfactants, which are monomeric surfactants linked by a spacer group, with unique aggregation behavior and higher surface activity than monomer surfactants, have received extensive attention [2][3][4]. In recent years, polysurfactants with unique properties have been demonstrated to be essential for various applications, such as drug delivery [5], nanoparticle synthesis [6][7][8], and the fabrication of polymer surfactant mixing systems [9].…”