Formaldehyde Nanocomposites Research Articles

Adsorption of Malachite Green Dye in Aqueous Solution Using Low-Cost Synthesis of Zinc Oxide Urea Formaldehyde Nanocomposite as Adsorbent

Adsorption of Malachite Green Dye in Aqueous Solution Using Low-Cost Synthesis of Zinc Oxide Urea Formaldehyde Nanocomposite as Adsorbent

Synthesis of Ferric Oxide Urea Formaldehyde Nanocomposite for Adsorptive Removal of Malachite Green Cationic Dye from Aqueous Media

Synthesis of Ferric Oxide Urea Formaldehyde Nanocomposite for Adsorptive Removal of Malachite Green Cationic Dye from Aqueous Media

Preparation of Melamine Formaldehyde Foam and a Melamine-Formaldehyde-Organo-Clay Nanocomposite and Hybrid Composites

Mineral fillers can be added to thermoset polymers to improve thermal conductivity and deformation behavior, shrinkage, impact strength, dimensional stability and molding cycle time. This study aims to prepare various hybrid composites (MFHCs) using melamine formaldehyde foam (MF), a melamine formaldehyde organo-clay nanocomposite (MFNC) and also pumice as primary filler, and gypsum, kaolinite and a hollow glass sphere as secondary filler. It also focuses on the study of some mechanical properties and thermal conductivities, as well as their microscopic and spectroscopic characterization. For this, firstly, organo-clay was prepared with the solution intercalation method using montmorillonite, a cationic surfactant and long-chain hydrocarbon material, and then was produced using a melamine formaldehyde nanocomposite with in situ synthesis using a melamine formaldehyde pre-polymer and organo-clay. Finally, hybrid composites were prepared by blending various minerals and the produced nanocomposite. For morphological and textural characterization, both FTIR spectroscopy and XRD spectra, as well as SEM and HRTEM images of the raw montmorillonite (MMT), organo-montmorillonite (OMMT), pure polymer (MF) and prepared hybrid composites, were used. Spectroscopic and microscopic analyses have shown that materials with different textural arrangements and properties are obtained depending on effective adhesion interactions between polymer–clay nanocomposite particles and filler grains. Mechanical and thermal conductivity test results showed that melamine-formaldehyde-organo-clay nanocomposite foam (MFCNC) exhibited a very good thermal insulation performance despite its weak mechanical strength (λ: 0.0640 W/m K). On the other hand, among hybrid composites, it has been determined that the hybrid composite containing hollow glass beads (MFCPHHC) is a material with superior properties in terms of thermal insulation and mechanical strength (λ: 0.642 W/m K, bulk density: 0.36 g/cm3, bending strength: 228.41 Mpa, modulus of elasticity: 2.22 Mpa and screw holding resistance: 3.59 N/mm2).

Pd(0)-impregnated SBA-15/melamine–formaldehyde nanocomposite: an efficient and reusable catalyst for reduction in nitroarenes

Pd(0)-impregnated SBA-15/melamine–formaldehyde nanocomposite: an efficient and reusable catalyst for reduction in nitroarenes

Dynamic mechanical analysis, electrical properties and water sorption behaviour, of phenol formaldehyde nanocomposite reinforced with multiwalled carbon nanotubes

The goal of this research is to synthesise Phenol-formaldehyde nanocomposites containing pure multiwalled carbon nanotubes using an in-situ polymerisation process. The impact of filler loadings (MWCNT) with various weight percentages in the composite was explored in this research. The visco-elastic, electrical, morphological, and water sorption behaviour of the nanocomposites were investigated. The influence of MWCNT loading on the dynamic mechanical analysis, water uptake, electrical behaviour was examined. Using in-situ polymerisation, an effort was made to generate non agglomerated and homogenius dispersion of multiwalled carbon nanotubes (MWCNT) in the PF composite. The influence of MWCNT dispersion on the viscoelastic characteristics, electrical, morphological, and water sorption behaviour of PF-MWCNT nanocomposites has been thoroughly investigated. When compared to neat PF, lower filler loading (0.05 wt%, 0.08 wt percent) resulted in greater AC conductivity. According to DMA investigation of PF-MWCNT, 0.15 wt% has a greater storage modulus and 0.05 has a higher glass transition temperature. The addition of MWCNT has effectively reduced the water uptake of the entire nanocomposite.

High corrosion protective behavior of water-soluble conducting polyaniline–sulfonated naphthalene formaldehyde nanocomposites on 316L SS

In this paper, water-soluble conducting polyaniline–sulfonated naphthalene formaldehyde nanocomposites (PAni–SNF NCs) were successfully synthesized by a one-step in-situ polymerization method. The structural characterization of the synthesized PAni–SNF NCs was confirmed by Fourier transform-infrared spectroscopy (FT–IR), Ultraviolet-visible spectroscopy (UV–Vis), Proton nuclear magnetic resonance spectroscopy (1H NMR), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Dynamic light scattering (DLS), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Conductivity measurements, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and Cyclic voltammetry (CV). The corrosion protective behavior of 316L stainless steel (316L SS) in 1 M HCl was examined using electrochemical measurements and weight loss methods at various PAni–SNF NCs. The inhibition efficiency of PAni–SNF NCs was found to 97.9% and 99.3% in the case of PANS-3 and PANS-10 NCs at the optimum concentration of 50 ppm. The potentiodynamic polarization method demonstrated that PAni−SNF NCs acted as a mixed-type inhibitor in both studied NCs. Moreover, adsorption of PAni−SNF NCs inhibitor on the 316L SS surface followed the Langmuir isotherm model. The present report provides extremely significant findings in preparing and designing novel and sustainable corrosion inhibitors with high inhibition efficiency.

Effect of MWCNT carboxylation on mechanical, thermal and morphological behaviour of phenol formaldehyde nanocomposites

Phenol-formaldehyde resin is an inevitable polymer material because of their excellent properties like heat resistance, chemical resistance, creep resistance, and low water sorption. But the drawback associated with PF matrix is buckling and brittleness. The incorporation of nanofillers can effectively reduce these problems. Carbon nanotubes is one among the nanofiller which is widely used to enhance the mechanical, thermal, electrical properties of the host matrix.The present study deals with the synthesis and comparison of two Phenol-formaldehyde nanocomposites incorporated with pristine multiwalled carbon nanotubes and carboxylated multiwalled carbon nanotubes via in-situ polymerisation technique. The effect of filler loading (MWCNT, MWCNT-COOH) with different weight percentages (0.05 wt%, 0.08 wt%, 0.12 wt%, 0.15 wt%) has been investigated in this study. Pristine MWCNT was functionalised with carboxyl groups and confirmed by XRD, FT-IR, CHN analysis, X-ray photoelectron spectroscopy, AFM and Raman spectra. All these analysis showed successful funtionalisation of pure MWCNT. The prepared nanocomposites were compared by mechanical, thermal and morphological analysis. The effect of both fillers on tensile strength, stress-strain, young’s modulus and elongation at break were also analysed. The addition of MWCNT and MWCNT-COOH have enhanced the mechanical and thermal properties of the prepared nanocomposite. The mechanical properties of PF-MWCNT nanocomposite showed a maxima for 0.12 wt% and for PF-MWCNTCOOH nanocomposite it was 0.08 wt%. Higher thermal stability was exhibited for 0.15 wt% MWCNT loading. The thermal stability enhanced by the addition of MWCNT COOH upto 0.12 wt% and then declined. Moreover the prepared nanocomposites were morphologically characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM) and from the fracture analysis it is clear that the reinforcements brought plastic deformation of phenol-formaldehyde nanocomposite from brittle to more ductile material. From the TEM image it was clear that the presence of carboxyl groups attached on MWCNT reduced agglomeration in PF matrix. Halpin-Tsai modelling was done for comparing experimental and theoretical values of tensile modulus and it illustrates good correlation.

High efficient corrosion inhibitor of water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites for 316 L stainless steel

AbstractIn this work, new water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites (PPy–SMF NCs) were first synthesized by one‐step in‐situ polymerization of pyrrole with FeCl3 in the presence of various mole ratios of sulfonated melamine formaldehyde (SMF). The characterization of the PPy–SMF NCs was investigated via ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray, dynamic light scattering, transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, and conductivity measurements. The resulting PPy–SMF NCs were proved to improve the solubility, electrical properties, and thermal stability. The anti‐corrosion performance of PPy‐SMF NCs on 316 L stainless steel (316 L SS) was examined using electrochemical impedance spectroscopy, potentiodynamic polarization, and weight‐loss method. The result showed that the PPy–SMF NCs acts as a mixed‐type inhibitor, as well as a protective layer to 316 L SS against corrosion in 3.5% NaCl solution. The Langmuir adsorption isotherm was well fitted and suitable to explain the adsorption behavior of the PPy‐SMF NCs on 316 L SS surface. The inhibition efficiency of PPy‐SMF NCs is 99% by the weight‐loss method which could be attributed to the protective layer formed on 316 L SS surface by the adsorption of PPy‐SMF NCs.

Viscoelastic and electrical properties of RGO reinforced phenol formaldehyde nanocomposites

AbstractGraphene oxide was reduced (RGO) by naturally abundant potato starch and incorporated in phenol formaldehyde resin (PF). The PF/RGO nanocomposites were successfully fabricated by the combination of solution processing and compression molding. Here, nanocomposites composed of 0.05 wt% to 1 wt% RGO were prepared. The incorporation of RGO into the PF matrix was significantly affecting the dynamic mechanical characteristics of the nanocomposites such as storage and loss modulus and tan δ. The degree of entanglement (N), effectiveness of filler (βf), reinforcement efficiency factor (r), cross‐link density (vc), and adhesion factor (A) were evaluated from the modulus values. Besides, the phase behavior of the nanocomposites was analyzed with help of Cole–Cole plot. The electrical properties of the nanocomposites have been studied concerning change in filler loading and frequency. The dielectric constant (ε′), dielectric loss (ε″) and conductivity were increased with increase in wt% of filler for the entire range of frequencies (20 Hz to 30 MHz) and the results showed that the electrical conductivity of the nanocomposites can be explained by percolation theory. The Maxwell‐Garnet model was employed to calculate the theoretical dielectric constant of PF/RGO nanocomposites.

Synthesis and characterization of cobalt nanocomposite using aniline-formaldehyde resin

Abstract In this work, cobalt doped aniline-formaldehyde nanocomposite with average particles size of 32.16 nm were prepared by simple chemical method. The concentrations of such nanocomposites were investigated by Scanning electron microscope (SEM), Transmission electron microscope (TEM), Atomic electron microscopy (AFM) and X-ray diffraction. XRD. The synthesized nanocomposite was formed in cubes and spherical shaped. The roughness and average maximum height of cobalt nanocomposite is 141 nm and 106 nm respectively. The X-RD confirms that the cobalt doped aniline formaldehyde nanocomposite was formed in crystalline in nature.

In situ synthesis of graphene-phenol formaldehyde composites and their highly-efficient radical scavenging effects under the γ irradiation

As a category of long-term protective coating, phenol formaldehyde (PF) has been extensively applied in the nuclear industry. However, PF might emerge adverse degradation processes under the γ ray irradiation environment, which greatly restricts its further applications as the highly-efficient protective coatings. For the sake of addressing this issue, herein, a novel phenol noncovalent modified graphene oxide/phenol formaldehyde nanocomposite (GPF) has been constructed via in situ guiding phenol formaldehyde micromolecules format on the well-dispersed graphene oxide surface. Electron spin resonance and electrochemical tests intensively demonstrate that the highly dispersed graphene could act as an enhanced radical scavenger and retain the corrosion resistance properties for the GPF composites under the gamma irradiation environment.

Magnetic mesoporous poly-melamine–formaldehyde: an efficient and recyclable catalyst for straightforward one-pot synthesis of imidazo[1,2-a]pyridines

Magnetically separable mesoporous poly-melamine–formaldehyde nanocomposite (Fe3O4@mPMF) has been synthesized and characterized by FTIR spectroscopy, SEM, XRD spectroscopy and EDS. The magnetically separable Fe3O4@mPMF catalyst had excellent efficiency for the synthesis a wide diversity of imidazo[1,2-a]pyridines by a three-component reaction of a 2-aminopyridine, aldehyde and isocyanide in good-to-excellent yields within a short reaction time, through an environmental friendliness and straightforward procedure. The nanocomposite that is easily recoverable and also found to be reusable can be recovered and reused when the reaction is completed for several times without distinct deterioration in catalytic activity.

Intercalation structure and toughening mechanism of graphene/urea‐formaldehyde nanocomposites prepared via in situ polymerization

AbstractBased on the industrialized graphene (GN) product, a series of graphene/urea‐formaldehyde nanocomposites were synthesized via in situ polymerization by incorporation of silicon coupling agent with terminal amino groups (SA) as the compatibilizer. The results showed that addition of SA coupling agent led to much more efficient grafting of UF molecules on the GN surface with high layer thickness by formation of hydrogen bonding, and thus complete exfoliation and uniform dispersion of GN were achieved for the composites. Compared with neat UF, the addition of 1.0 wt% GN resulted in a roughly 25% increase in tensile strength and 12% increase in impact strength; meanwhile the impact fracture surfaces of the composite showed obvious ductile fracture characteristics, indicating the reinforcing and toughening effect of GN on the UF matrix. With increasing GN content, the storage modulus, glass transition temperature and crosslinking density of UF increased, while the tan δmax decreased, suggesting that a double crosslinking network structure with GN centered crosslinking point and chemical crosslinking point of UF molecular chains formed, leading to improvement in the stiffness of the composites. The present work showed promising potential for developing high performance UF resin on an industrial scale. © 2017 Society of Chemical Industry

Thermally reduced graphene oxide/polymelamine formaldehyde nanocomposite as a high specific capacitance electrochemical supercapacitor electrode

Thermally rGO/polymelamine formaldehyde nanocomposite shows good behavior as supercapacitor electrode with 2271 F g−1 specific capacitance in 10 A g−1 with excellent stability.

Thermal Ablation and Laser Shielding Characteristics of Ionic liquid-microseeded Functionalized Nanoclay/Resorcinol Formaldehyde Nanocomposites for Armor Protection

ABSTRACTThermal ablation performance, thermal stability, and laser shielding characteristics of tailored nanoclay-resorcinol formaldehyde nanocomposites have been investigated. RF resin was modified with ionic liquid and a range of weight loadings of functionalized nanoclay through a facile in situ polymerization technique. Thermal ablation testing of the modified resin shows lower back-face temperature profiles and distinct reduction in linear and mass ablation rates, while thermogravimetric analysis results show enhanced thermal stability. Significant increase in the laser ablation energy and increased d-spacing of the surface modified nanoclay in resorcinol formaldehyde nanocomposite connote favorable polymer intercalation/exfoliation within the silicate layers.

Preparation, Characterization, and Properties of In Situ Formed Graphene Oxide/Phenol Formaldehyde Nanocomposites

Graphene oxide (GO) has shown great potential to be used as fillers to develop polymer nanocomposites for important applications due to their special 2D geometrical structure as well as their outstanding mechanical, thermal, and electrical properties. In this work, GO was incorporated into phenol formaldehyde (PF) resin by in situ polymerization. The morphologies and structures of GO sheets were characterized by FTIR, XRD, and AFM methods. The structure and properties of the GO/PF nanocomposites were characterized using FTIR, XRD, DSC, and TGA methods. Effects of GO content, reactive conditions, and blending methods on the structure and properties of GO/PF nanocomposites were studied. It was found that due to the well dispersion of GO sheets in polymer matrix and the strong interfacial interaction between the GO sheets and PF matrix, the thermal stability and thermal mechanical properties of the GO/PF nanocomposites were greatly enhanced.