Characterization of a polyaniline/pre-oxidized fiber felt electromagnetic wave absorbing composite

2021 ◽  
pp. 004051752110519
Author(s):  
Yi Wang ◽  
Yuanjun Liu ◽  
Xiaoming Zhao

Firstly, a polyaniline/pre-oxidized fiber felt composite was prepared by in situ polymerization using pre-oxidized fiber felt as the substrate, aniline as the monomer, ammonium persulfate as the oxidant, and p-toluenesulfonic acid as the dopant. Secondly, the electromagnetic wave absorbing property and tensile property of the polyaniline/pre-oxidized fiber felt composite were investigated. Finally, the structure and composition were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and differential scanning calorimetry. The results show that the reflection loss of the polyaniline/pre-oxidized fiber felt composite is the smallest at the 3000 MHz frequency, reaching –8.23 dB, and the average surface resistance is 2059.84 Ω, with good conductivity. The characterization analysis shows that polyaniline has been successfully loaded on the pre-oxidized fiber felt, and the protonation reaction occurs at the nitrogen atom on the imine -N-. The polyaniline structure is doped by p-toluenesulfonic acid with a certain degree of order and crystallinity, and the composite has good thermal stability.

2011 ◽  
Vol 399-401 ◽  
pp. 444-448 ◽  
Author(s):  
Jun Qian Mu ◽  
Yi Yang ◽  
Zhi Han Peng

In this paper, a novel flame retarded MCA-PA6 (PA6 incorporated with melamine cyanurate) resin was synthesized by in-situ polymerization. The synthetic product was characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), Fourier transform infrared spectroscope (FTIR), thermogravimetry analysis (TG), differential scanning calorimetry (DSC) and elemental analysis. The result showed that good dispersability were obtained in MCA-based PA6 prepared successfully. Meanwhile, the maximum mass loss rate appeared at about 450 °C and the residual char increased from 1.2 wt% to 3.2 wt% at 500 °C due to the existence of MCA.This research revealed MCA-PA6 owned a good thermal stability, hence there was potential flame retardance.


2012 ◽  
Vol 217-219 ◽  
pp. 142-145
Author(s):  
Hong Wang ◽  
Yong Zhong Jin ◽  
Tao Wang ◽  
Di Liu ◽  
Xue Fei Li

Ni/poly(m-toluidine)(PMT) nanocomposites were prepared by in situ chemical oxidative polymerization of m-toluidine (MT) monomer in the presence of Ni powder, with ammonium persulfate (APS) as oxidant and citric acid (C6H8O7) as dopant. The resultant products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and superconducting quantum interference device magnetometer (SQUID). The results exhibited that Ni/PMT nanocomposites show a ferromagnetic behavior with saturation magnetization strength (Ms) and coercivity of 28.4emu/g and 105.8Oe at room temperature. The prepared Ni/PMT composites were soft and ferromagnetic materials. Moreover, thermal Stability of nanocomposites was also investigated.


2016 ◽  
Vol 30 (12) ◽  
pp. 1603-1614 ◽  
Author(s):  
BTS Ramanujam ◽  
S Radhakrishnan ◽  
SD Deshpande

Polyphenylene sulfide (PPS)-expanded graphite (ExGr) conducting nanocomposites have been prepared by powder mixing and in situ polymerization routes after sonicating ExGr particles in acetone. Synthesized PPS has been used to make powder mixed composites. The powder mixed composites exhibit a percolation threshold of 3 wt% due to the formation of graphite nanosheets. When PPS-ExGr composites are prepared by in situ polymerization route, very low electrical percolation threshold less than 0.5 wt% ExGr is obtained. The low percolation threshold obtained is attributed to better dispersion of ExGr nanosheets in the polymer matrix when compared to powder mixed composites. The synthesized PPS has been characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. The formation of graphite nanosheets has been confirmed by transmission and scanning electron microcopy analysis.


2017 ◽  
Vol 14 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Fatima Zeggai ◽  
Mohammed Belbachir ◽  
Aicha Hachmaoui

In this work we report a simple way for the conducting polymer nanocomposites synthesis using on algerian hydrophilic natural Montmorillonite (MMT) nanoclay named Maghnite (Mag) as dopant. The electrochemical properties study of the following conducting polymers: poly(4-aminobenzylamine) (P4ABA) and polyaniline (PANI) nanocomposites with copper maghnite (Mag-Cu) were successfully prepared by In-Situ polymerization, in presence of inorganic nanolayers of clay, and oxidizing agent ammonium persulfate. The synthesis of copolymers was developed at different feed mole fractions of monomer. The products were characterized by the Fourier transform Infrared (FT-IR), the ultraviolet-visible (UV–vis) spectroscopies and X-ray diffraction (XRD). The results showed that the in-situ polymerization produced real nanocomposites containing aniline and 4-aminobenzylamine units.


2020 ◽  
Vol 6 (2) ◽  
pp. 686-688
Author(s):  
Phalak Mrunalini ◽  
Rajendra Waghulade ◽  
Yogesh Toda

This work reports synthesize of polypyrrole nano powder by chemical in-situ polymerization of pyrrole in aqueous solution and ammonium persulfate solution which acts as oxidant. It is characterized by X-ray diffraction (XRD), Fourier infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD spectrum reveals that the materials are amorphous in nature. FTIR analysis confirms that all peaks are the main characteristic of PPy. SEM analysis showed that the powder has a uniform granular morphology and the size varies from ∼500 nm to 1 μm. The micrograph of polypyrrole reveals the presence of globular particles. The formed particles are irregular in nature. The results show that the fibers are chemically formed as spherical nanostructures.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Orietta Monticelli ◽  
Zenfira Musina ◽  
Francesca Ghigliotti ◽  
Saverio Russo ◽  
Valerio Causin

AbstractNanocomposites based on polyamide 6 (PA6) and montmorillonite-type (MMT) commercial clays, either unmodified or organically modified, were prepared by in-situ polymerization of ε-caprolactam (CL). The above materials were characterized in detail by a number of experimental techniques, including transmission electron microscopy (TEM), wide angle X-ray diffraction (WAXD), infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The formation of nanostructured systems was checked not only for the commonly used ω-aminoacid-modified clay, but also for other types of organoclays. In general, a correlation was found between nanoscopic swelling of the clay in molten CL, measured by X-ray diffraction, and level of clay dispersion in PA6. Specifically, with the most swellable clays, completely exfoliated nanocomposites were obtained. However, also layered silicates modified by compatibilizers having carboxy groups, because of the active role of latter in CL polymerization, formed delaminated nanocomposites despite their low degree of swelling in CL monomer. Both molecular mass and crystallinity of the polyamide matrix were found to be strongly influenced by the presence of specific layered silicates. In particular, some characterization techniques (WAXD, FTIR) have evidenced a close relationship between the MMT used and PA6 crystal structure. Namely, PA6 γ-form is promoted by clay with compatibilizer bearing the carboxy group, which is able to induce the polymer to be tethered on the silicate layers, thus provoking conditions of restricted mobility to occur.


2006 ◽  
Vol 317-318 ◽  
pp. 669-672 ◽  
Author(s):  
D.H. Kim ◽  
Seong Soo Park ◽  
B.S. Jun ◽  
Jong Kook Lee ◽  
Kyu Hong Hwang ◽  
...  

Polymer/layered silicate nanocomposities were prepared by in situ polymerization with microwave process. The influence of the amount of clay on the structure and thermal properties for the synthesized nanocomposites were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). It was found that the structure of nanocomposites, an intercalated/exfoliated structure, depended on the clay content.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Fan Xufen ◽  
Chen Dajun

AbstractPoly (ethylene terephthalate) (PET)/Attapulgite (AT) nanocomposites were prepared via in-situ polymerization. According to the observation of transmission electron microscopy (TEM), attapulgite is well dispersed in the PET matrix in a nanometer scale. The influence of attapulgite content on the nonisothermal crystallization kinetics was studied using a classical Avrami equation with Jeziorny method. The crystalline structures of the pure PET and PET/AT nanocomposites with different amount of AT (0.2%, 0.5%, 1%, 2%) were characterized by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods. It was found that the crystallization temperature for PET/AT nanocomposites with 0.2% and 0.5% content of AT were higher than pure PET and the rate of crystallization of all PET/AT nanocomposite samples increased significantly which indicated that attapulgite could be used as an effective nucleating agent in PET. However, with the addition of AT, smaller crystalline size, more crystalline defects and lower degree of crystallization was demonstrated.


2009 ◽  
Vol 24 (8) ◽  
pp. 2728-2735 ◽  
Author(s):  
A. Saritha Chandran ◽  
Sunil K. Narayanankutty

Conducting nylon 6 fibers were prepared by in situ polymerization of aniline on to the fiber surface, after providing a chemical etching treatment to the fibers using chromic acid. The properties of the etched and polyaniline (PANI) coated fibers were evaluated using scanning electron microscopy, x-ray photoelectron spectroscopy, infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential scanning calorimetry. Though the etching process caused a marginal decline in the mechanical properties of the fiber, it provided a reasonably rough surface for PANI adhesion and enhanced the conductivity of the fiber. The conductivity increased from 4.22 × 10−2 to 3.72 × 10−1 S/cm at an etching time of 4 h.


2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.


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