Emulsion Copolymerization of Methyl Methacrylate/Butyl Acrylate/Iodine System to Monosize Rubbery Nanoparticles Containing Iodine and Triiodide Mixture

Abstract

Monosize poly(methyl methacrylate-co-butyl acrylate) rubbery nanoparticles, approximately 95 nm in diameter, containing iodine and triiodide with a molar ratio of 2.78 of the former to the latter, were synthesized by emulsion polymerization. Iodine and the two-monomer mixture were polymerized by sodium metabisulfite and potassium persulfate as a redox initiation system. Iodine evolution to triiodide during the copolymerization was traced by ultraviolet–visible spectroscopy. Iodine addition to the monomer mixture and its copolymerization not only reduced the copolymer average molecular weight by 30%, but also led to the formation of more MMA-enriched chains. The redox initiation system also changed 26% of initial iodine molecules into triiodide, while the rest were encapsulated as molecular iodine. During thermal annealing, the lower rate of triiodide decomposition into iodine and iodide in comparison with the iodine evaporation rate broadened both thermogravimetric and heat flow curves.

Preparation and characterization of a novel highly hydrophilic and antifouling polysulfone/nanoporous TiO2nanocomposite membrane

“…A silane-based coupling agent was used to reduce surface energy of the nanoparticles, minimizing their agglomeration in the membrane. It has already been reported that establishment of physical interactions upon addition of inorganic particles into polymers could lead to change in the position and intensity of peaks in FTIR spectrum [31]. In the NTiO 2 spectrum, the peak which appears at wavenumbers around 830-1110 cm −1 can be attributed to Si-O covalent bond while the peak near 2950 cm −1 is ascribed to alkyl groups of the modifier [32].…”

Synthesis of dual thermo‐ and pH‐sensitive poly(N‐isopropylacrylamide‐co‐acrylic acid)‐grafted cellulose nanocrystals by reversible addition‐fragmentation chain transfer polymerization

“…By increasing temperature, PNIPAAm chains at the surface of CNC become hydrophobic and therefore collapsed at the surface. However, PNIPAAm chains stretch in aqueous medium freely at lower temperatures as a result of their hydrophilic behavior …”

Method of Moments Applied to Most-Likely High-Temperature Free-Radical Polymerization Reactions

“…The polymerization involves three main (primary) reactions: initiation, propagation and termination [1]. In the initiation reaction, an initiator such as a thermal initiator usually generates free radicals at temperatures above 60 • C [2,3]. The polymerization may also start spontaneously (without adding any known initiator) by a monomer or impurities at high temperatures, typically 140-350 • C [4,5].…”