Microwave-assisted nitroxide-mediated radical polymerization of acrylamide in aqueous solution

Role of External Field in Polymerization: Mechanism and Kinetics

The past decades have witnessed an increasing interest in developing advanced polymerization techniques subjected to external fields. Various physical modulations, such as temperature, light, electricity, magnetic field, ultrasound, and microwave irradiation, are noninvasive means, having superb but distinct abilities to regulate polymerizations in terms of process intensification and spatial and temporal controls. Gas as an emerging regulator plays a distinctive role in controlling polymerization and resembles a physical regulator in some cases. This review provides a systematic overview of seven types of external-field-regulated polymerizations, ranging from chain-growth to step-growth polymerization. A detailed account of the relevant mechanism and kinetics is provided to better understand the role of each external field in polymerization. In addition, given the crucial role of modeling and simulation in mechanisms and kinetics investigation, an overview of model construction and typical numerical methods used in this field as well as highlights of the interaction between experiment and simulation toward kinetics in the existing systems are given. At the end, limitations and future perspectives for this field are critically discussed. This state-of-the-art research progress not only provides the fundamental principles underlying external-field-regulated polymerizations but also stimulates new development of advanced polymerization methods.

Synthesis and Viscosimetric Behavior of Poly(acrylamide-co-2-acrylamido-2-methylpropanesulfonate) Obtained by Conventional and Adiabatic Gel Process via RAFT/MADIX Polymerization

High molar masses homopolymers of both acrylamide (AM) and 2-acrylamido-2-methylpropanesulfonate (AMPS) as well as poly(AM-stat-AMPS) exhibiting a large range copolymer composition has been obtained via the optimization of a purely adiabatic gel process. Monomer concentrations ranging from 2.0 to 3.47 M have been successfully tested while keeping the control of the molar masses up to 5 × 10⁶ g mol^-1. The products have been characterized in terms of molecular mass and viscosimetric properties.

Dispersion polymerization of acrylamide with living character and controlled morphologies initiated and mediated by cobalt porphyrin

Dispersion polymerization of acrylamide (AM) catalyzed by cobalt porphyrin [cobalt tetramethoxyphenylporphyrin, (TMOP)Co(ii)] with the feature of living radical polymerization (LRP) in alcohol/water or dimethylformamide (DMF)/water is described.

Nitroxides: applications in synthesis and in polymer chemistry

This Review describes the application of nitroxides to synthesis and polymer chemistry. The synthesis and physical properties of nitroxides are discussed first. The largest section focuses on their application as stoichiometric and catalytic oxidants in organic synthesis. The oxidation of alcohols and carbanions, as well as oxidative C-C bond-forming reactions are presented along with other typical oxidative transformations. A section is also dedicated to the extensive use of nitroxides as trapping reagents for C-centered radicals in radical chemistry. Alkoxyamines derived from nitroxides are shown to be highly useful precursors of C-centered radicals in synthesis and also in polymer chemistry. The last section discusses the basics of nitroxide-mediated radical polymerization (NMP) and also highlights new developments in the synthesis of complex polymer architectures.