Thermal Properties Of Nanocomposites Research Articles

Mechanical and thermal properties of a newly developed sepiolite filler-filled rPET/PA11 thermoplastic nanocomposites

The study examined the impact of sepiolite filler-filled nanocomposites in a novel recycled polyethylene terephthalate (rPET)/polyamide (PA11)/joncryl® blend. Sepiolite filler significantly improved the mechanical and thermal properties of nanocomposites. A twin-screw extruder and injection moulding machines were employed to manufacture five different formulations of nanocomposites. The tensile strength (37.6 MPa) and Young's modulus (944.25 MPa) of the blend NCS-0 improved with the addition of 2 phr of sepiolite. The tensile strength and Young's modulus of nanocomposites (NCS-2) were recorded at 41.3 MPa and 974.25 MPa, respectively. The lowest sepiolite filler content (2 phr) had the maximum tensile strength among all other ratios. The flexural strength of NCS-2 was recorded at 47.3 MPa. The tensile and flexural modulus of nanocomposites were significantly enhanced by incorporating 2 phr of sepiolite. The impact strength of NCS-2 (252.98 MPa) was much higher than NCS-8. The addition of sepiolite filler increased the glass transition temperature (Tg) by 38 %. The onset of decomposition temperature (Tonset) of the blend (NCS-0) improved by 20–22° Celsius (oC). Overall, nanocomposites with 2 phr sepiolite demonstrated the ultimate mechanical and thermal properties. These results explored new ways of using rPET/PA11 compatibilized blend in the automotive industry.

Effects of Nanocellulose Extracted from Pineapple Leaf Fiber Incorporation on the Physico-Chemical and Thermal Properties of Reinforced Epoxy Nanocomposites

The effects of nanocellulose extracted from pineapple leaf fiber on the physico-chemical and thermal properties of epoxy nanocomposite are reported. Nanocellulose was added to the epoxy in different amounts of loadings (0.5, 1.0, 1.5, and 2.0 wt.%) to prepare nanocomposites. The physico-chemical and thermal properties of the nanocellulose reinforced epoxy nanocomposites were investigated. Surface characterization of the nanocomposite was done using scanning electron microscopy (SEM). Functional groups of the nanocomposites were evaluated using fourier transform infrared (FTIR) spectroscopy. Thermal properties of the nanocomposites were investigated using thermogravimetric analyzer (TGA) and differential thermal analyzer (DTA). Experimental results revealed that the 0.5, 1.0, and 1.5 wt.% nanocellulose loadings were homogeneously distributed and well-dispersed in the composite matrix as indicated in the SEM images. However, aggregation was observed in the matrix with 2.0 wt.% nanocellulose loading. Moreover, FTIR spectra revealed that the absorbance of the vibrational mode corresponding to the interaction of nanocellulose and epoxy matrices significantly increases as the nanocellulose loading ratio increased. Furthermore, thermal analysis (TGA/DTA) showed that the incorporation of nanocellulose improved significantly the thermal properties of epoxy nanocomposites.

Use of phosphorylated chitosan/alumina nanoadditives for polymer performance improvement

In this research, a new generation of ternary nanocomposites based on poly(ethylene terephthalate) (PET), phosphorylated chitosan and surface modified alumina nanoparticles were fabricated in four steps. The phosphorylation process was targeted for the insertion of phosphorus moieties as a flame retardant agent in the final PET nanocomposite. Likewise, environmentally friendly nano-alumina was used for PET matrix to improve the thermal properties of PET in collaboration with organic anchored phosphorus moieties. Alternatively, the presence of bio-safe modified alumina nanoparticles in combination with phosphorylated chitosan simultaneously improved the antibacterial activity and thermal properties of the PET matrix. Furthermore, the effects of the phosphorylated chitosan and alumina nanoparticles on the morphology and thermal properties of nanocomposites were inspected by different approaches. The structure and distribution of the nanoscale particles in PET were analyzed by scanning electron microscopy. In addition, differential scanning calorimetry and thermogravimetric analyses were used for the in-depth evaluation of the thermal properties of prepared nanocomposites. Prepared nanocomposites showed better growth inhibition activities against Escherichia coli bacteria compared to the PET and PET/phosphorylated chitosan samples. Also, the thermal characteristics of prepared nanocomposites were considerably improved.

Structure and thermal properties of copper-polypropylene based nanocomposites

Polymer nanocomposites based on PP/Cu were obtained by the combining of ex-situ casting solution and hot pressing methods. The structure of polymer nanocomposites was characterized by XRD, SEM, EDS, AFM and FT-IR spectroscopy analysis. The thermal properties were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was found that the addition of copper nanoparticles to the PP polymer matrix increases the thermal stability of the polymer, and this thermal stability reaches its maximum value at 3% content of copper nanoparticles in the polymer. The reason for the increase in the thermal properties of nanocomposites is associated with the formation of a more perfect, dense and ordered structure of PP-based composites and the fact that nanoparticles play the role of a nucleus of crystallization for polymer matrices.

Application of butane-1,4-diyl bis(2-mercaptoacetate) as dithiol prepolymer for preparation of polythiourethane and clay-based nanocomposites

In this work, we have synthesized butane-1,4-diyl bis(2-mercaptoacetate) (BBMA) as dithiol compound via esterification of 1,4-butanediol and thioglycolic acid. Fourier-transform infrared (FT-IR) and proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopies were used to prove the success of the synthesis process. BBMA as a prepolymer has been reacted with 4,4'-diphenylmethane diisocyanate (MDI) to prepare neat poly(thiourethane) (PTU). Moreover, Cloisite 30B (1–5 wt.%) has been used to prepare clay/poly(thiourethane) nanocomposites. Finally, the effect of Cloisite 30B content on structural, thermophysical, and thermal properties of nanocomposites has been investigated. Results showed that PTU0 as a neat polythiourethane had an amorphous structure with good thermal stability whereas its glass transition temperature was < 0°C. The incorporation of Cloisite 30B into PTU resulted in a significant improvement of thermal stability, whereas it elevated crystallinity and thermophysical properties up to 2 wt.%.

Obtaining and studying the properties of composites based on high pressure polyethylene with cobalt-containing nanofi llers

The effect of cobalt nanoparticles stabilized by a polyethylene matrix on the physical-mechanical and thermal properties of nanocomposites based on low density polyethylene was studied using X-ray phase (XRD) and differential thermal (DTA) analyzes.An improvement in the strength and deformation parameters, as well as the thermal-oxidative stability of the obtained nanocomposites was revealed, which can be attributed to the effects of structural modification of the polymer matrix.Small amounts of nanofiller introduced into the polymer play the role of structure-forming agents - artificial nuclei of crystallization, which contributes to the formation of a small-spherolite structure in the polymer, characterized by improved physical, mechanical and thermal properties of the obtained nanocomposite.

Effect of modification on thermal stabilities and thermal degradation kinetics of poly(buthylmethacrylate)/multi-walled carbon nanotube nanocomposites

ABSTRACT Modified multi-walled carbon nanotubes (MWCNTs) were prepared from commercially purchased MWCNTs with different chemical reactions. Nanocomposites were synthesised by the solvent casting method. The effects of functional groups, filling ratios and surfactants on thermal properties of nanocomposites were investigated. The structural, thermal and morphological properties of MWCNT and nanocomposites were investigated using Fourier transform infrared spectrophotometer, Brunauer–Emmett–Teller surface area measuring device, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The novel increases in the thermal properties of poly(butylmethacrylate) (PBMA) were observed by adding MWCNT samples into a PBMA matrix. T g values of nanocomposites were higher than those of PBMA films. The data obtained from the thermograms of nanocomposites at different heating rates were analysed with Kissinger, FWO and Friedman equations. The activation energies of the nanocomposites were higher than those of PBMA films.

ANALYSIS OF THE INFLUENCE OF THE NATURE OF THE FILLER SURFACE ON THE PROPERTIES OF HYBRID ORGANIC-INORGANIC NANOCOMPOSITES BASED ON EPOXY OLIGOMER

The aim of this work was to investigate the influence of the chemical nature of the filler surface on the properties of hybrid organo-inorganic nanocomposites based on epoxy oligomer ED-20 in the presence of nanoscale functional filler of inorganic origin - aerosil, with different surface nature. The influence of the chemical nature of the surface of highly dispersed aerosil on the thermal properties of nanocomposites based on epoxy oligomer ED-20 has been studied. The peculiarities of the process of thermooxidative destruction have been studied. It is shown that the introduction of highly dispersed aerosil in the amount of 0.5% in the epoxy matrix does not lead to changes in the thermal properties of composites, and the nanofiller in the amount of 5% improves thermal stability of composites. The kinetics of the curing process of epoxy nanocomposites was studied by IR-spectroscopy. The influence of the presence of functional groups on the nanofiller surface on rate and the degree of conversion of epoxy groups was determined. The presence of hydroxyl groups on the surface of A-300 contributes to the rate of conversion of epoxy groups to a greater extent, compared with aerosil with a modified surface, which contains on the surface methyl groups capable of blocking reactive groups. It is established that the rate of conversion of epoxy groups in the presence of aerosil decreases in the range of ED-20 &gt; ED-20 + A-300 &gt; ED-20 + AM-300. The sorption properties of epoxy nanocomposites have been studied. It is established that the sorption process proceeds at a higher rate when the matrix is filled with unmodified aerosil. The mechanism of influence of the chemical nature of the filler surface and content on formation and properties of epoxy nanocomposites is discussed.

Synthesis, Characterization and Thermal Properties of Oxo Methacrylate-Containing Polymer/Clay Nanocomposites

In this study, synthesis and characterization of polymer/clay based nanocomposites was performed using 2-(4-methoxyphenyl amino)-2-oxoethyl methacrylate (MPAEMA) and organoclay. The amount of organoclay in nanocomposites synthesized by in situ polymerization method was determined as 3% and 5%. FTIR, XRD, and SEM were used as characterization techniques. It was determined from XRD and SEM results that the morphology of nanocomposites exfoliated. Then, the thermal properties of nanocomposites were investigated using the TGA/DTA/DTG simultaneous system. In thermal analysis, it was seen that the thermal stability increased when the clay amount increased. It is thought that this newly synthesized synthetic polymer/clay nanocomposites with natural clay content will serve different areas due to its environmentally friendly-biodegradable properties.

Interface adjustment between poly(ethylene terephthalate) and graphene oxide in order to enhance mechanical and thermal properties of nanocomposites

AbstractThere is great interest in the use of graphene and derivatives in the production of polymer nanocomposites as it provides improvements in the properties of the materials to which they are associated. Such improvements depend heavily on filler dispersion and the interaction between the nanomaterials and the matrix. This work aimed to study the compatibility of graphene oxide (GO) with a poly(ethylene terephthalate) matrix. For this, graphite was modified using Hummers method, using reaction times of 3 and 6 h. The obtained GO was functionalized with amine, amide, and magnetite groups (FGO). The effects of the oxidation degree, functionalization and concentration of the nanofillers on the dispersion and consequently on the properties of the polymer nanocomposites were evaluated. The nanocomposites were synthesized by the solid–solid deposition method followed by the melt mixing technique. It was observed that lower concentrations of nanofiller associated with the lower degree of oxidation and functionalization improved the interaction of the nanofillers with the matrix, which resulted in better mechanical properties under tensile stresses for strain at break, maximum stress, Young's modulus and toughness. It was also observed that the glass transition and crystallization of nanocomposites increased due to a nucleating effect of the nanofillers.

An experimental investigation on tool wear behaviour of uncoated and coated micro-tools in micro-milling of graphene-reinforced polymer nanocomposites

Nanomaterials such as graphene have been added to various matrices to enhance mechanical, thermal and electrical properties for various applications requiring intricate designs at the micro-scale. At this scale, mechanical micro-machining is utilised as post-processing to achieve high surface quality and dimensional accuracy while still maintaining high productivity. Therefore, in this study, the machinability of polymer nanocomposites in micro-scale (micro-machinability) is investigated. Graphene (0.3 wt%)-reinforced epoxy nanocomposites were fabricated using traditional solution mixing and moulding. The samples were then subjected to micro-milling at various cutting speeds using three different micro-tools, including uncoated, diamond and diamond-like carbon (DLC) tools. Mechanical and thermal properties of nanocomposite were also used to support the discussions. The result indicates that the DLC-coated tool shows better performance than the other tools for less tool wear, improved surface quality and less cutting forces.

Investigation of graphene/graphene oxide reinforced polyurethane nanocomposite: A molecular dynamics approach

Abstract The interaction interface between the 2D nanomaterials such as graphene and polymers play a crucial role in determining mechanical and thermal properties of nanocomposites. This study presents a molecular dynamics approach to investigate surface adsorption of polyurethane on graphene and graphene oxide models. Graphene (G) and graphene oxide (GO) samples were created of the same 2D sizes of 96 × 57 A2, where the number of carbonyl, carboxyl, epoxy, and hydroxyl groups were altered to obtain GO samples with varied oxidation degrees. The highly functionalized samples exhibited better adsorption in comparison to pristine graphene. Furthermore, radial distribution function was analyzed and used for validation of simulation. Finally, the effects of G/GO addition into polymer on the mechanical properties of polyurethane were examined. It was found that addition of graphene resulted in enhanced Young’s modulus with a significant increase from 0.42 GPa to 4.88 GPa, whereas highly oxidized G sheets resulted in proportionally lower figures such as 0.54 GPa, 1.39 GPa.

Superparamagnetic Behaviour and Surface Analysis of Fe3O4/PPY/CNT Nanocomposites

The superparamagnetic property of nanomaterials such as Fe3O4 has been considered to be promising for various applications. In this paper, Fe3O4/PPY/CNT nanocomposites were synthesized with utilizing natural iron sand by a coprecipitation method. The as-precipitated Fe3O4 NPs were combined with carbon nanotubes (CNTs) using conductive polypyrrole (PPY) as linking agents. The Fe3O4/PPY/CNT nanocomposites were systematically characterized by FE-SEM, EDS, XRD, BET, and FTIR. Furthermore, the effects of CNTs on magnetic and thermal properties of nanocomposites were investigated by VSM and thermal gravimetric analysis (TGA), respectively. The composites exhibited significant decrease of coercivity value with the content of CNTs increasing. The VSM result confirmed that Fe3O4/PPY/CNT nanocomposites were superparamagnetic. It was found that by increasing the amounts of CNTs, the magnetization of Fe3O4/PPY/CNT nanocomposites gradually decreased. The addition of CNTs is intended to improve the mesoporous property as proved by BET analysis which has the potential application as a nanocatalyst.

Analysis of mechanical and thermal properties of epoxy multiwalled carbon nanocomposites

The main objective of this study was to investigate the efficiency of the sonication process and of multi-walled carbon nanotubes (MWCNTs) content on the mechanical and thermal properties of an epoxy matrix. Three different sonication powers (25, 50 and 75 W) were used to disperse the MWCNTs (0.2%, 0.4% and 0.6% wt.) in the epoxy matrix. Tensile tests were performed to determine the mechanical properties of the nanocomposites, while the thermal properties were determined by the thermogravimetric analysis (TGA) and the Differential Exploratory Calorimetry (DSC). Finally, a SEM analysis was used to investigate the morphology of the tensile fractured surface and the dispersion of the nanotubes in the polymeric matrix, since the quality of dispersion influences the mechanical and thermal properties of nanocomposites. It was found that the addition of carbon nanotubes to the epoxy matrix and the parameters of the sonication process affect the mechanical and thermal properties of nanocomposites. An increase of approx. 14% in tensile strength and 15% of Young’s modulus, when compared to the pure epoxy matrix was found for 75 W sonication power output and 0.6% MWCNTs weight percentage. The thermal analysis indicated that the presence of MWCNTs increased the Tonset of the nanocomposites when compared to pure epoxy resin. Finally, increasing the sonication power output leads to higher Tg of the nanocomposites studied here.

The role of graphene interactions and geometry on thermal and electrical properties of epoxy nanocomposites: A theoretical to experimental approach

The influence of dispersion procedure and nanofiller geometry on thermal and electrical properties of graphene nanoplatelet (GNP) based composites has been investigated. A theoretical model, based on the contacts between adjacent nanoparticles, has been proposed aiming to connect thermal and electrical properties. It has been observed that GNP overlapping (type I) induces a decrease on thermal conductivity. Its effect on electrical conductivity is more complex and depends on the areas of overlap and in-plane contacts (type II). A higher type I area in comparison to type II implies an increase of electrical conductivity with overlapping whereas the opposite effect is found when type II area is higher than type I. The predicted results of the theoretical model fitted experimental measurements at different GNP contents and three roll milling processing conditions, giving a better overview of the influence of GNP geometry and interactions on electrical and thermal properties of nanocomposites.

Effects of graphene quantum dot (GQD) on photoluminescence, mechanical, thermal and shape memory properties of thermoplastic polyurethane nanocomposites

A group of shape memory polyurethane‐based nanocomposites containing graphene quantum dot nanoparticles (GQDs) were prepared via in‐situ polymerization method. GQD nanoparticles were synthesized by a facile and rapid microwave‐assisted method and characterized by Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction pattern, field emission scanning microscopy, transmission electron microscopy, and fluorescence analysis. Chemical structure and hydrogen bonding index (HBI[C=O]) of the nanocomposites were analyzed via FTIR spectra. The results show that the incorporation of GQDs in PU matrix reduces HBI(C=O) of nanocomposites. Crystalline structure and thermal properties of the nanocomposites were investigated by differential scanning calorimetry. As results indicate, nucleation effect of GQDs raises crystallinity content of the samples. Mechanical examinations indicate that incorporation of GQDs improves Young's modulus of the nanocomposites, while their elongation at break values are reduced. In addition, shape memory analyses reveal that the presence of GQDs in PU matrix increases the shape fixity ratios in nanocomposites.

Thermogravimetric and dynamic mechanical analysis of woven glass/kenaf/epoxy hybrid nanocomposite filled with clay

ABSTRACT This research studies the thermogravimetric and dynamic mechanical analysis of woven glass/kenaf/epoxy hybrid nanocomposites filled with clay. Epoxy resin modified with 1.0 wt% silicon is sonicated with varying clay loading of 1.0, 3.0 and 5.0 wt%. The resin is then spread onto alternating woven glass and NaOH-treated woven kenaf. Thermogravimetric analysis (TGA) reveals the benefits of dispersing clay onto the thermal properties of nanocomposite. Higher residue and higher temperature at 10 wt% mass loss is observed in clay nanocomposite. In addition to that, kenaf treatment, woven glass reinforcement and epoxy modification also help in improving the thermal stability of composites. Dynamic mechanical analysis (DMA) reveals that TKG1% composite possessed the highest storage modulus at room temperature with 136.74% higher than UKG1% composite due to the polymer chain diffusion between well dispersed clay structures. TKG1% also achieved the highest loss modulus which indicates strongest internal friction among other composites. Despite that, TKG1% composite exhibited the lowest Tg which is 72°C. This could be reasoned with the elimination of hemicellulose due to fibre treatment that is responsible for stiffness in natural fibre. Elimination of hemicellulose is proven through Fourier-transform Infrared Spectroscopy (FTIR) analysis conducted on treated kenaf fibre at wavenumber 1514, 1696 and 1726 cm−1.

Magnetic regulating the phase change process of Fe3O4-paraffin wax nanocomposites in a square cavity

The addition of external force provides an alternative way to promote the application of phase change materials in thermal-energy storage, space heating, and cooling systems. However, the experimental investigation using external magnetic force to regulate the phase change process is still limited. Here, magnetic Fe3O4 nanoparticles were added to paraffin wax to form phase change nanocomposites with enhanced thermal properties and controllable magnetism. The thermal properties of nanocomposites were measured and the phase change processes under magnetic controlling were experimentally and numerically investigated. A two-dimensional enthalpy-based lattice Boltzmann model with considering the external magnetic force was proposed and the measured thermal properties were used in the simulation. Good agreement between the experiment and simulation was achieved. The effects of different mass fractions of Fe3O4 nanoparticles (0, 1, 2, 3 and 4 wt%), magnetic directions, magnetic field intensities (0, 20, 40, 60 mT) on the phase change characteristics are discussed. The heat transfer efficiency in a square cavity filled with the nanocomposites developed more quickly when the paraffin wax was doped with a higher Fe3O4 mass fraction. Moreover, the phase change characteristics were controlled by the intensity and direction of the magnetic field. This study presents a method to achieve magnetically regulating phase change heat transfer characteristics that have potential applications in the energy-storage industry.

Various properties of recycled PET (rPET)/organoclay nanocomposite fibres

ABSTRACTToday, the production of polymeric nanocomposite materials is one of the most important research fields. In this study, it was aimed to investigate the effect of organoclay particles on recycled polyester (rPET) fibre properties. In the literature, the studies mostly concerned with the engineering plastic applications, and hence the investigations were done on pellet and injection-moulded rPET/organoclay nanocomposite samples. Actually, fibre application is the most important market for PET wastes, but unfortunately, there are only a few papers regarding rPET/organoclay composite fibre properties. In the study, rPET/organoclay nanocomposites were prepared by melt intercalation process with different modified organoclay types (3 wt-%), and multifilament fibres were spun by the melt spinning method. Morphological and thermal properties of nanocomposites and surface structure, tensile, and thermal stability properties of the fibres were tested. The results indicated that the distribution of clay particles and organoclay types had a significant influence on various fibres properties.

Получение и исследование свойств металлсодержащих нанокомпозитов на основе эпоксидиановой смолы

The influence of additions of nanofillers (NF) containing nanoparticles of copper and zinc oxides, stabilized by polymer matrix of high pressure polyethylene, prepared by mechano-chemical method on peculiarities of structure and properties of the metal-containing nanocomposites on the basis of epoxy diane resin (ED-20) by the methods of differential-thermal (DTA) and IR-spectral (IRS) and X-ray diffraction (XRD) has been investigated. It has been shown that an introduction of the metal-containing NF in composition with ED-20 shifts the cold curing reaction temperature from 90 to 75 °C, and hot curing from 125 to 100 °C and favors increase of its thermal stability, which is confirmed by growth of activation energy of thermal-oxidative destruction (Eact) from 210 to 225 kJ/mol. It has been shown that the nanoparticles of copper oxide increase the thermal properties of ED-20 and are the catalysts of curing reaction as evidenced by peak height on curing curve. In this case, the nanoparticles of zinc oxide practically don’t influence on thermal properties of nanocomposites on the basis of ED-20.