Magnetic high density polyethylene nanocomposites reinforced with in-situ synthesized Fe@FeO core-shell nanoparticles

High-density polyethylene composites filled with micro- and nano-particles of nickel ferrite: magnetic, mechanical, and thermal properties

With the increasing demand of new magnetic materials for modern technological application alternatives to conventional magnetic materials, the development of lightweight polymer magnetic composites has become a prominent research area. For this perspective, a new magnetic material was developed using 30 wt% nickel ferrite micro and nanoparticles as fillers for a high-density polyethylene matrix. The development process began with the synthesis of NF-micro and NF-nanoparticles using solid-state and co-precipitation techniques, respectively, followed by extrusion molding and injection molding. The success of the synthesis process and the purity of the spinel structure phase were confirmed. Additionally, using the extrusion process produced polymer magnetic composite materials with a good distribution of magnetic particles within the polymer matrix, resulting in good magnetic properties and enhanced mechanical properties of the polymer magnetic materials.

Biosynthesis of Iron Oxide Nanoparticles Using Leaf Extract of Ruellia tuberosa: Mechanical and Dynamic Mechanical Behaviour Kevlar-Based Hybrid Epoxy Composites

One of the more enticing, ecologically responsible, as well as safe and sustainable methodologies is eco-friendly nanomaterial synthesis. Vegetation materials will be used as reductants instead of toxic substances for synthesising nanoparticles. The current study used Ruellia tuberosa (RT) leaf extract digest to synthesise FeO nanomaterials, which were then characterised using XRD. Following that, microbially produced FeO molecules were mixed with a Kevlar-based polymeric matrix to study the blended consequences. To examine the interbreeding, the current experimental analyses were performed, including both static and dynamic mechanical characteristics. The addition of FeO nanofillers improved the elastic modulus, tensile strength, and storage modulus of the nanocomposite. Impact force uptake has been raised to a certain extent by the addition of nanoparticles. The findings of this research show that incorporating FeO nanofillers into Kevlar fabrics is a promising technique for increasing the mechanical characteristics of hybrid laminated composites. As per DMA evaluation, the sample without nanomaterials had a more volcanic lava response, which is a useful thing for body systems for missile use. Another critical aspect of a nanoparticles-filled nanocomposite that must be addressed is the relatively uniform scattering of padding as well as the development of interfacial adhesion in such a combination. The presence of FeO fillers in polymeric composites is confirmed by XRD analysis.

Iron Oxide Powder as Responsible for the Generation of Industrial Polypropylene Waste and as a Co-Catalyst for the Pyrolysis of Non-Additive Resins

For the synthesis of polymeric resins, it is of great importance to review the raw materials and the equipment to be used to avoid the presence of compounds that may affect the effectiveness of the polymerization and the characteristics of the plastic to be obtained. Iron oxide is a compound that can be present in reactors after maintenance due to the techniques used and the cleaning of this equipment, and it can affect the characteristics of the resins, reducing their quality. In this study, the presence of FeO in different concentrations was evaluated to determine its effects on the properties and pyrolysis of polypropylene resins by using X-ray refraction to determine the elements of the samples, evaluating thermal degradation by TGA, the variation in molecular weight by measuring the MFI, and the compounds obtained from pyrolysis by chromatography. The results showed that the thermal degradation decreased as the FeO concentration increased, while for the MFI, the relationship was directly proportional. The evaluation of the compounds obtained from pyrolysis showed an increase in the production of alcohols, alkynes, ketones, and acids, and a decrease in alkanes and alkenes, showing that FeO affects the properties of polypropylene and the compounds that are produced during pyrolysis.

Manufacture and Characterization of Polypropylene (PP) and High-Density Polyethylene (HDPE) Blocks for Potential Use as Masonry Component in Civil Construction

The lack of suitable destinations for plastics materials can be a global environmental problem. The alternative use of materials for sustainable construction encourages the standardization of waste and promotes effective social, environmental and economic gains at the local level and ensures savings and income for communities. The aim of this paper is the development, manufacture, and characterization of PP and HDPE recycled polyolefin blocks as masonry components in civil construction. These blocks were manufactured by the rotational molding process. Besides this, the mechanical, physical, impact and flammability properties of the blocks were studied. In conclusion, HDPE showed better behavior than PP in tests realized.

Polysulfone metal-activated carbon magnetic nanocomposites with enhanced CO2 capture

In the present study, polysulfone (PSF)-activated carbon nanocomposites were synthesized by a melt mixing technique. Here, 2 wt% activated carbon (CA, CA-Ni, and CA-Co) was used as filler, and effects on thermal, mechanical, magnetic, morphological, and carbon dioxide capture properties were studied. The pyrolysis of wood sawdust produced carbon materials activated by Co and/or Ni salt. The thermal degradation and the amount of metal in the carbon materials were investigated by thermogravimetric analysis. The maximum degradation temperature showed an improvement of up to 3 °C, while the initial degradation temperature decreased up to 4 °C with the addition of metal-activated carbons. The values of T g estimated by differential scanning calorimetry appear to be practically identical for pure PSF and its nanocomposites. The elasticity modulus of the nanocomposite shows an enhancement of 17% concerning the neat PSF. The water contact angle showed a decrease with the incorporation of the fillers, indicating the hydrophilic nature of the composite. The carbon dioxide sorption capacity of the nanocomposite showed an enhancement of almost 10% in contrast to neat PSF. Ferromagnetic behavior of the thermoplastic nanocomposite was observed with the introduction of 2.0 wt% metal-carbonized filler. The exceptional magnetic properties, for a thermoplastic material such as polysulfone, make it promising for various industrial applications.

Combination of Magnetic Lignocellulosic Particles, High-Density Polyethylene, and Carbon Black for the Construction of Composites with Tunable Functionalities

Biocomposites with unique functionalities for tailored applications are promising products for a sustainable future. In this work, a process concept of forming functional composites by combining of high-density polyethylene, carbon black, and magnetic lignocellulosic particles (wood flour) was demonstrated. The impacts of process parameters on morphologies, crystalline phase, and magnetic intensity of wood flour were identified. Magnetic, antistatic and mechanical properties of biocomposites were also evaluated. Lignocellulosic particles were encapsulated with magnetic nanoparticles, and the resulting composites exhibited tunable magnetic and antistatic properties. A noticeable feature is that magnetic nanoparticles were uniformly distributed in the matrices as a result of anchorage to lignocellulosic particles. Magnetic lignocellulosic particles and polymer resin had good compatibility. The resulting composites provided another opportunity for shielding materials, which could reduce the radiation in the living environment. These findings could provide a tunable strategy of the tailored use of lignocellulose-based composites in functional applications.

Manipulating the dimensional assembly pattern and crystalline structures of iron oxide nanostructures with a functional polyolefin

Controlled crystalline structures (α- and γ-phase) and assembly patterns (1-D, 2-D and 3-D) were achieved in the synthesized iron oxide (Fe2O3) nanoparticles (NPs) using polymeric surfactant-polypropylene grafted maleic anhydride (PP-g-MA) with different concentrations. In addition, the change of the crystalline structure from the α- and γ-phase also led to the significantly increased saturation magnetization and coercivity.

Strong and moldable cellulose magnets with high ferrite nanoparticle content

A major limitation in the development of highly functional hybrid nanocomposites is brittleness and low tensile strength at high inorganic nanoparticle content. Herein, cellulose nanofibers were extracted from wood and individually decorated with cobalt-ferrite nanoparticles and then for the first time molded at low temperature (<120 °C) into magnetic nanocomposites with up to 93 wt % inorganic content. The material structure was characterized by TEM and FE-SEM and mechanically tested as compression molded samples. The obtained porous magnetic sheets were further impregnated with a thermosetting epoxy resin, which improved the load-bearing functions of ferrite and cellulose material. A nanocomposite with 70 wt % ferrite, 20 wt % cellulose nanofibers, and 10 wt % epoxy showed a modulus of 12.6 GPa, a tensile strength of 97 MPa, and a strain at failure of ca. 4%. Magnetic characterization was performed in a vibrating sample magnetometer, which showed that the coercivity was unaffected and that the saturation magnetization was in proportion with the ferrite content. The used ferrite, CoFe2O4, is a magnetically hard material, demonstrated by that the composite material behaved as a traditional permanent magnet. The presented processing route is easily adaptable to prepare millimeter-thick and moldable magnetic objects. This suggests that the processing method has the potential to be scaled-up for industrial use for the preparation of a new subcategory of magnetic, low-cost, and moldable objects based on cellulose nanofibers.

One-pot synthesis of size- and morphology-controlled 1-D iron oxide nanochains with manipulated magnetic properties

Polypropylene grafted maleic anhydride (PP-MA, 2500 g mole(-1)) has demonstrated its unique capability to synthesize 1-D ferromagnetic hard (292.7 Oe) γ-Fe2O3 nanochains made of ~24 nm nanoparticles vs. PP-MA with 8000 g mole(-1) for the synthesis of 1-D ferromagnetic soft (70.5 Oe) γ-Fe2O3 nanochains (30 nm) made of flowerlike nanoparticles.

Synthesis of highly efficient flame retardant high-density polyethylene nanocomposites with inorgano-layered double hydroxides as nanofiller using solvent mixing method

High-density polyethylene (HDPE) polymer nanocomposites containing Zn2Al-X (X= CO3(2-), NO3(-), Cl(-), SO4(2-)) layered double hydroxide (LDH) nanoparticles with different loadings from 10 to 40 wt % were synthesized using a modified solvent mixing method. Synthesized LDH nanofillers and the corresponding nanocomposites were carefully characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, etc. The thermal stability and flame retardancy behavior were investigated using a thermo gravimetric analyzer and microscale combustion calorimeter. Comparing to neat HDPE, the thermal stability of nanocomposites was significantly enhanced. With the addition of 15 wt % Zn2Al-Cl LDH, the 50% weight loss temperature was increased by 67 °C. After adding LDHs, the flame retardant performance was significantly improved as well. With 40 wt % of LDH loading, the peak heat release rate was reduced by 24%, 41%, 48%, and 54% for HDPE/Zn2Al-Cl, HDPE/Zn2Al-CO3, HDPE/Zn2Al-NO3, and HDPE/Zn2Al-SO4, respectively. We also noticed that different interlayer anions could result in different rheological properties and the influence on storage and loss moduli follows the order of SO4(2-) > NO3(-) > CO3(2-) > Cl(-). Another important finding of this work is that the influence of anions on flame retardancy follows the exact same order on rheological properties.

Flame-retardant electrical conductive nanopolymers based on bisphenol F epoxy resin reinforced with nano polyanilines

Both fibril and spherical polyaniline (PANI) nanostructures have successfully served as nanofillers for obtaining epoxy resin polymer nanocomposites (PNCs). The effects of nanofiller morphology and loading level on the mechanical properties, rheological behaviors, thermal stability, flame retardancy, electrical conductivity, and dielectric properties were systematically studied. The introduction of the PANI nanofillers was found to reduce the heat-release rate and to increase the char residue of epoxy resin. A reduced viscosity was observed in both types of PANI-epoxy resin liquid nanosuspension samples at lower loadings (1.0 wt % for PANI nanospheres; 1.0 and 3.0 wt % for PANI nanofibers), the viscosity was increased with further increases in the PANI loading for both morphologies. The dynamic storage and loss modulii were studied, together with the glass-transition temperature (T(g)) being obtained from the peak of tan δ. The critical PANI nanofiller loading for the modulus and T(g) was different, i.e., 1.0 wt % for the nanofibers and 5.0 wt % for the nanospheres. The percolation thresholds of the PANI nanostructures were identified with the dynamic mechanical property and electrical conductivity, and, because of the higher aspect ratio, nanofibers reached the percolation threshold at a lower loading (3.0 wt %) than the PANI nanospheres (5.0 wt %). The PANI nanofillers could increase the electrical conductivity, and, at the same loading, the epoxy nanocomposites with the PANI nanofibers showed lower volume resistivity than the nanocomposites with the PANI nanospheres, which were discussed with the contact resistance and percolation threshold. The tensile test indicated an improved tensile strength of the epoxy matrix with the introduction of the PANI nanospheres at a lower loading (1.0 wt %). Compared with pure epoxy, the elasticity modulus was increased for all the PNC samples. Moreover, further studies on the fracture surface revealed an enhanced toughness. Finally, the real permittivity was observed to increase with increasing the PANI loading, and the enhanced permittivity was analyzed by the interfacial polarization.

Maghemite Intercalated Montmorillonite as New Nanofillers for Photopolymers

In this work, maghemite intercalated montmorillonite (γFe₂O₃-MMT)/polymer nanocomposites loaded with 1 or 2 wt.% of nanofillers were obtained by photopolymerization of difunctional acrylate monomers. The γFe₂O₃-MMT nanofillers were prepared by a new method based on the in situ formation of maghemite in the interlayer space of Fe-MMT using a three step process. X-ray diffraction (XRD), chemical analysis, TG/DTA and transmission electron microscopy (TEM) characterization of these nanofillers indicated the efficiency of the synthesis. When following the kinetics of the photopolymerization of diacrylate-γFe₂O₃-MMT nanocomposites using FTIR spectroscopy no significant inhibition effect of the nanofillers was observed at a loading up to 2 wt.%. These innovative nanocomposites exhibit improved mechanical properties compared to the crude polymer.