Synthesis of Magnetic Nanocomposite Based on Amphiphilic Polyurethane Network Films

Abstract

Magnetic nanocomposites, showing extremely small coercivity and hysteresis loop, were synthesized using amphiphilic polyurethane networks based on amphiphilic urethane acrylate nonionomer (UAN) precursor chains. Three kinds of UAN gel films were synthesized through UV‐curing of UAN chains in the absence of a solvent, or crosslinking polymerization of UAN/water and UAN/DMAc mixtures. Even though these gel films were synthesized with the same UAN, these UAN gel films had very different microstructures depending on the preparation conditions; as a consequence, magnetic composites prepared with these crosslinked films exhibited very different size and morphology of magnetic nanoparticles. Atomic force microscopy and mechanical property measurements showed that UAN gel film (UANH) synthesized with UAN/water mixture had the highly microphase‐separated structures whereas the gel films synthesized via UV‐curing (UANV) or polymerization of UAN/DMAc mixture (UAND) had relatively homogeneous structures. The largest ellipsoidal particles were formed in UANH gel films and the smallest ellipsoidal particles and rod‐shaped particles were made up in UANV gel and UAND gel film, which was confirmed by transmission electron microscopy.Transmission electron micrograph of magnetic composite film prepared with UANV.magnified imageTransmission electron micrograph of magnetic composite film prepared with UANV.

Synthesis of Poly(urethane acrylate‐co‐styrene) Films Containing Silver Nanoparticles by a Simultaneous Copolymerization/in situ Electron Transfer Reaction

“…It is possible to synthesize free-standing polymer films containing magnetic nanoparticles using crosslinked UAN films. [12][13][14] The size and morphology of the magnetic nanoparticles dispersed within these matrixes can be controlled by varying the degree of hydrophilic/hydrophobic microphase separation in amphiphilic UAN by varying the type of solvent used and the weight ratio of hydrophobic monomer/UAN in the synthesis of polymeric matrices.…”

Fabrication of inorganic/polymer nanocomposite membranes containing very high silica content via in situ surface grafting reaction and reactive dispersion of silica nanoparticles: Proton conduction, water uptake, and oxidative stability

“…15,16 The average molecular weight of the synthesized UAN was 6700 with a polydispersity of 2.01. Molecular structure of UAN chain is schematically presented at Figure 1.…”

Synthesis of microphase‐separated solvent‐free solid polymer electrolyte nanocomposite films using amphiphilic urethane acrylate precursors

“…[23][24][25] Each reaction was performed in a 500 mL four-neck vessel equipped with stirrer, thermometer, and an inlet system for nitrogen gas. Synthesis procedure and molar ratio of UAN chain was described in detail in our previous reports.…”

“…Synthesis procedure and molar ratio of UAN chain was described in detail in our previous reports. [23][24][25] The polystyrene equivalent molecular weight of synthesized UAN chains is a 6700 (g/mol) weight average molecular weight with a polydispersity of 1.93. Expected molecular structure of UAN chain was schematically illustrated in Figure 1.…”

“…Since urethane acrylate nonionomer (UAN) chains used in this study have hydrophobic polypropylene oxide (PPO)-based urethane-linked backbone and hydrophilic polyethylene oxide (PEO) segment at the same backbone, UAN can form microphase-separated structure at various conditions via hydrophilic/hydrophobic microphase separation. [23][24][25] So, unlike conventional polyurethane-based SPE films, it could be expected that SPE films synthesized through copolymerization of UAN/various monomers would have very different microstructures with type of monomer used, which may strongly influence their ion conductivity.…”