Synthesis of monodispersed polyacrylonitrile microspheres by dispersion polymerization

Abstract

Monodispersed polyacrylonitrile (PAN) microspheres shape have been successfully synthesized by dispersion polymerization in the presence of polyvinylpyrolidone (PVP) as stabilizer. Transmission Electron Microscopy (TEM) and Particle Size and Distribution Analyzer were used to characterize the morphology and dispersibility of PAN microspheres, respectively. Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) were applied to characterize the structure of PAN. Finally, the crystallinity of PAN microspheres was investigated by X-ray Diffraction (XRD). The results show that PAN microspheres have a regular sphere shape and narrow dispersity with a monodispersity index of 1.17. The crystallization of PAN and the existence of PVP layer affect the morphology of PAN microspheres. The effects of various polymerization factors on the particle size distribution of PAN microspheres have also been studied.

Quantification of copolymer composition (methyl acrylate and itaconic acid) in polyacrylonitrile carbon-fiber precursors by FTIR-spectroscopy

“…Most frequently, NMR spectroscopy, usually 1 H and 13 C (and, recently, solid-state techniques), is applied till date. [35][36][37][38][39] However, this approach is expensive and time-intensive, requires highly skilled personnel, and not very suitable for the rapid analysis of large numbers of samples. Alternatively, the control of the copolymer production is frequently based on the functional organic analysis using titrimetry.…”

Effects of Amino-Functionalized Carbon Nanotubes on the Crystal Structure and Thermal Properties of Polyacrylonitrile Homopolymer Microspheres

“…However, the crystallinity and the crystal size of the amino-CNT/PAN microspheres is 31.41% and 57.17 Å, respectively. The lower crystallinity of the amino-CNT/PAN microspheres compared to that of the PAN homopolymer is because the amino-CNTs disrupt the fairly regular macromolecular structure of the PAN homopolymer [ 35 , 36 , 37 ]. However, the higher crystal size of the microspheres is attributed to the nano-size of the CNTs, which induces the PAN macromolecular chain orientation around the surface of amino-CNT [ 38 ], similar to the CNT/PAN composite fibers [ 12 , 39 ].…”

Synthesis and Shape Control of Uniform Polymer Microparticles by Tailored Adsorption of Poly(ethylene oxide)‐b‐Poly(ε‐caprolactone) Copolymer

“…About 100 particles were directly analyzed from the SEM images, and the average was taken. The average diameter of the particles ( D n ) and polydispersity index (PDI) were obtained from the following equations: , PDI = D w / D n , where D w is the weight‐averaged diameter, n is the total number counted, and D i is the diameter of particle i …”

“…where D w is the weight-averaged diameter, n is the total number counted, and D i is the diameter of particle i. 28,29 Characterization of Particle Morphology and Surface Chemistry. Chemistry of particle surface was analyzed with an X-ray photoelectron spectrometry (XPS, R3000, VG Scienta, Uppsala, Sweden).…”