Dispersion polymerization of acrylamide int-butyl alcohol/water media

Abstract

We have performed dispersion polymerization of acrylamide in tert-butyl alcohol/water mixture-using hydroxypropyl cellulose and ammonium persulfate as the stabilizer and the initiator, respectively-to study the effects that the concentration of monomer, initiator, and stabilizer, the tert-butyl alcohol/water ratios as polymerization media, and the reaction temperature have on, among other things, the polymerization kinetics, particle sizes, and molecular weights. The polymerization rate increased upon increasing the concentration of the monomer, initiator, and stabilizer, the water content in the tert-butyl alcohol/water media, and the polymerization temperature. The average particle size of the lattices increased upon increasing the concentration of initiator, the polymerization temperature, and the water content in the tert-butyl alcohol/water media, but it decreased upon increasing the concentration of monomer and stabilizer. The viscosity-average molecular weight increased upon increasing the concentration of monomer and stabilizer and the water content in the tert-butyl alcohol/water media, but it decreased upon increasing both the concentration of initiator and the polymerization temperature.

Optimization of the fabrication of novel stealth PLA-based nanoparticles by dispersion polymerization using D-optimal mixture design

“…Dispersion polymerization differs from the classical precipitation polymerization in that it occurs in the presence of a dissolved soluble amphiphilic polymer (or the in situ formed graft copolymer product) which is adsorbed on the surface of particles where it lowers the surface free energy and functions as a steric stabilizer 4,5,6,7,8 . It is a polymerization method in which all reacting monomers are soluble in the solvent medium that is a poor or non-solvent for the polymer being formed 8,9,10,11 .…”

Templateless Synthesis of Polyacrylamide-Based Nanogels via RAFT Dispersion Polymerization

“…Dispersion polymerization requires that the starting components prior to polymerization should be soluble in the solvent and post‐polymerization the generated polymer should be insoluble. Previous work on traditional free radical polymerization of AM in solvent mixtures of water with methanol or tert ‐butanol pointed to a cononsolvency property of PAM, that is PAM becomes less soluble in the mixtures of water with methanol or tert ‐butanol. We found that more than 60 vol% tert ‐butanol in the mixture was needed to achieve successful RAFT dispersion polymerization, and optimal results were typically obtained with 70 vol% for PAM‐based nanogels (Table S1, Supporting Information) and 80 vol% tert ‐butanol for P(AM‐ co‐ BA)‐based nanogels (BA refers to butyl acrylate).…”

Poly (acrylonitrile-co-methyl methacrylate) nanoparticles: I. Preparation and characterization

“…The figure shows that the average particle diameter increased with increasing the polymerization temperature. At high polymerization temperature, due to low concentration of high molecular weight chains in the medium, a few nuclei were produced, leading to a few larger sizes (Ki-Chang Lee et al, 2004).…”