Micro-chemical structure of polyaniline synthesized by self-stabilized dispersion polymerization

Abstract

A variety of NMR techniques were applied to the micro-chemical structural characterization of polyanilines prepared via an efficient synthetic method in a self-stabilized dispersion medium in which the polymerization was conducted in a heterogeneous organic/aqueous biphasic system without any stabilizers. Here, the monomer and growing polymer chain were shown to function simultaneously as a stabilizer, imparting compatibility for the dispersion of the organic phase, and as a form of flexible template in an aqueous reaction medium. Polymerizations predicated on this concept generated polyanilines with a low defect content: solution state 1 3 C-NMR and solid 1 3 C DD/CP/MAS spectroscopy indicated that the synthesized HCPANi and its soluble derivative, HCPANi-t-BOC, evidenced distinctly different NMR spectra with fewer side peaks, as compared to conventionally prepared PANis, and the complete structural assignments of the observed NMR peaks could be determined via the combination of both 1D and 2D techniques. Ortho-linked defects in HCPANi were estimated to be as low as 7%, as shown by a comparison of the integration of the carbonyl carbon resonance peaks.

Electrorheologically intelligent polyaniline and its composites

“…Details of the preparation procedure can be found in the literature. [76][77][78][79][80] Aniline monomer in HCl solution is polymerized using an ammonium peroxysulfate as a chemical oxidiant. PANI and its derivative particles: polymethylanilne (PMA), polyethylaniline (PEA), polymethoxylaniline (PMOA) and polyethoxyaniline (PEOA) were prepared by the similar chemical oxidation polymerization and then examined for their ER application, [81][82][83] in which these were typically synthesized from the chemical oxidation polymerization by feeding different aniline monomer derivatives.…”

Effect of crosslinking agents on the morphology of polymer particles produced by one-step seeded polymerization

“…Other techniques that can be used to produce spherical particles are emulsion 6,7 and dispersion polymerization, 8,9 which can yield monodisperse particles less than 1 and 1~10 μm, respectively. The compact or macroporous large uniform particles are also prepared by multi-step seeded polymerization techniques [10][11][12][13][14] despite the complex experimental procedure.…”

Self-doped carboxylated polyaniline: effect of hydrogen bonding on the doping of polymers

“…E-mails: Jayant_Kumar@uml.edu or Lynne_Samuelson@us.army.mil S.-C. Kim et al layer-by-layer self-assemblies, 10,11 nanotechnology, [12][13][14][15][16][17] and the detection of divalent metal ions. 18 In spite of many potential applications of carboxylated polyaniline (PCA), the chemical synthesis of this polymer has not been successful with chemical oxidative polymerization because of the poor solubility of a monomer in acidic media.…”