Thermal Stability Of Nanocomposites Research Articles

Enhancing polyethylene‐based nanocomposites through ethylene plasma polymerization of carbon nanotubes and sequential ultrasound dispersion with melt mixing method

AbstractThis study investigates the enhancement of linear low‐density polyethylene (LLDPE) nanocomposites with multiwalled carbon nanotubes (CNT) at concentrations of 1, 3, and 6% w/w. To improve the interfacial interaction between the CNT and the polymeric matrix, CNT were treated using ethylene cold plasma (P‐CNT) in a rotary reactor. The incorporation of CNT into the polymer was carried out by a melt mixing process (MMP) and a sequential ultrasound dispersion method followed by melt mixing (UDM‐MMP). The thermal stability of nanocomposites with 6% P‐CNT increased by 45°C compared to pristine LLDPE. Electrical conductivity reached 2.5 × 10−2 S/cm for nanocomposites with 6% CNT. The elastic modulus increased from 519.52 MPa (LLDPE) to 714.63 MPa (6% CNT) and 795.43 MPa (6% P‐CNT), which further improving to 731.42 MPa (6% CNT) and 841.27 MPa (6% P‐CNT) using UDM‐MMP. Additionally, yield stress rose from 16.35 MPa to 21.28 MPa (6% CNT) and 22.06 MPa (6% P‐CNT), reaching 21.47 MPa and 22.28 MPa with UDM‐MMP. Tensile strength increased from 21.31 MPa to 25.15 MPa (6% CNT) and 25.9 MPa (6% P‐CNT), achieving 26.82 MPa (6% P‐CNT) with UDM‐MMP. These results highlight a significant improvement in conductivity, rigidity, and mechanical strength, emphasizing their potential for advanced applications.

Development of carboxymethyl cellulose-based nanocomposite incorporated with ZnO nanoparticles synthesized by cress seed mucilage as green surfactant

This study aimed to enhance carboxymethyl cellulose (CMC)-based films by incorporating zinc oxide nanoparticles (ZnO NPs) and cress seed mucilage (CSM), with a view to augmenting the physical, mechanical, and permeability properties of the resulting nanocomposite films. For the first time, CSM was exploited as a green surfactant to synthetize ZnO NPs using hydrothermal method. Seven distinct film samples were meticulously produced and subjected to a comprehensive array of analyses. The findings revealed that the incorporation of CSM/ZnO-5 % improved the physical properties of the films, demonstrating a significant reduction in moisture content and water vapor permeability (WVP). Increasing the concentration of NPs in conjunction with CSM markedly decreased the solubility of the nanocomposites by up to 56 %. The films containing CSM/ZnO showed higher tensile strength and elongation at the break values. The UV absorption of the films exhibited a substantial rise with the addition of ZnO NPs, particularly with an increased content in the presence of CSM. The thermal stability of nanocomposites containing a high concentration of CSM/ZnO exhibited an improvement compared to the control sample. In light of these results, the CMC/CSM/ZnO-5 % film emerges as a promising candidate for a biocompatible packaging material, exhibiting favorable physical characteristics.

Crack-alleviated gold-assisted silica-titania three-layered fiber optic pH sensor

Gold-assisted silica-anatase (Au/AS) nanocomposite was synthesized by a sol-gel route at a low temperature (90 °C). Owing to sensing assessment, the mixture of indicators (bromophenol blue, phenol red, and creosol red) is encapsulated in Au/AS nanocomposite and deposited in three layers on optical fiber. TGA analysis confirmed the D-Au/AS nanocomposite thermal stability at higher temperatures ≤500 °C. SEM and EDX mapping confirmed the self-assembly of icosahedron structures at the nanometer scale. AFM revealed a porous triangular texture of three layers with RMS around 6 nm. The sensitivity of the three layers was estimated at around 17.7 counts/pH. The three layers of coated fiber revealed reversibility, stability, and fast response at 0.56 s in pH 12. The dynamic pH range of three-layer coated fiber was optimized at pH 1–12 and suggested that it has fast responsive sensing potential for applied fields.

Hydroxyapatite nanoparticles reinforced polyvinyl alcohol/chitosan blend for optical and energy storage applications

AbstractBiopolymer blend nanocomposite films composed of polyvinyl alcohol (PVA) and chitosan (CS) with varying quantities of hydroxyapatite (HA) nanoparticles were developed using a green solution casting method. The formation of blend nanocomposite was confirmed by Fourier‐transform infrared spectroscopy (FTIR), ultraviolet–visible (UV) spectrometer, field‐emission scanning electron microscopy (FE‐SEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Mechanical parameters such as tensile strength, percentage elongation at break, hardness, dielectric constant, and temperature‐dependent alternating current (AC) conductivity were analyzed. The bonding between the nanoparticles and PVA/CS blend was verified by the shift in distinctive peaks of blend in the nanocomposites to a higher wavenumber in the FTIR spectra. The UV spectra demonstrated the difference in absorbance and transmittance of the PVA/CS blend with the reinforcement of HA nanofillers. The bandgaps of the nanocomposites marginally decreased with an increase in nanoparticle loading. The SEM and XRD patterns revealed the ordered arrangement of the blend matrix due to the presence of nanoparticles. The assessment of thermal characteristics obtained from DSC and TGA demonstrated a clear increase in phase transition temperature and thermal stability of nanocomposites. The electrical conductivity measurement indicated a rise in dielectric constant and AC conductivity of blend nanocomposites with the addition of nanoparticles. The temperature‐dependent AC conductivity showed a reduction in activation energy as temperature and nanoparticle loading increased. The tensile strength and surface hardness of the PVA/CS blend nanocomposite increased with the dosage of HA content in the blend matrix.Highlights A series of polyvinyl alcohol (PVA)/chitosan (CS)/hydroxyapatite (HA) nanocomposites were prepared by the green method Enhanced optical property, thermal stability, and glass transition temperature Possess excellent dielectric constant and alternating current conductivity The inclusion of HA increased the mechanical strength of the PVA/CS blend A potential blend nanocomposite for flexible optoelectronic and charge storage devices.

Optical and Electrical Properties and Thermal Stability of Nanocomposites Containing CuO and ZrO2 Doped into Carboxy Methyl Cellulose for Batteries Applications

Optical and Electrical Properties and Thermal Stability of Nanocomposites Containing CuO and ZrO2 Doped into Carboxy Methyl Cellulose for Batteries Applications

Preparation and characterisation of polymer blends reinforced with nano-ZnO and study the thermal and electrical properties for industrial applications

Binary blends of unsaturated polyester (70%) and nitrile rubber (NR) (30%) and their composites are prepared. Zinc oxide nanoparticles (ZnONPs) were used as a filler in the hand-lay method. ZnONP weight ratios ranged from 0 to 3 ​wt.%. The ZnONPs were characterised using techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) to examine their crystalline structure and shape. The thermal and dielectric properties of the samples were examined as a function of filler content. Additionally, the theoretical and experimental densities of the nanocomposites were examined using the mixing rule and Archimedes’ principle, respectively. The thermal conductivity and diffusivity values exhibited variations between increasing and decreasing trends as the filler concentrations increased. Among all samples tested, the one containing 2.5% ZnONPs demonstrated the highest thermal conductivity and the lowest diffusivity when compared to the pure blend. As the ZnONP weight ratio increased, the corresponding dielectric constant value rose linearly, while the resistivity decreased linearly. Thermogravimetric analysis (TGA) revealed a significant improvement in the level of char yield and thermal stability of nanocomposites with increasing ZnONP concentration in the matrix.

INVESTIGATING THE EFFECT OF MICROWAVE IRRADIATION TIME, POLYETHYLENE GLYCOL CONCENTRATION AND pH ON THE PROPERTIES OF Mg-BASED BACTERIAL CELLULOSE NANOBIOCOMPOSITE

Mg-based bacterial cellulose nanobiocomposites (Mg-BCN) were produced assisted by microwave irradiation. In this study, the effects of the concentration of starter molecules, solution pH, and microwave irradiation time (MIT) on the properties of Mg-BCN were investigated. Tensile strength, structural properties, morphology and thermal stability of the nanocomposites were evaluated. According to the obtained results, an increase in the concentration ratio of starter molecules, pH, and MIT increased the formation of MgO, in comparison with Mg(OH)2. The nanocomposites synthesized with the 1:2 and 2:1 concentration ratio of magnesium acetate to polyethylene glycol, at pH 11 and with 3 minutes of MIT, had the largest tensile strength and crystallinity. Meanwhile, the opposite results were obtained with 1:1 and 1:0 ratios, at the mentioned pH and time. According to FESEM analysis, at pH = 9, the nucleation rate decreased and smaller particles were formed. Moreover, the results showed decreased possibility of agglomeration in the presence of polyethylene glycol (PEG). TGA results indicated that the thermal stability of all Mg-based nanocomposites is higher than that of pure cellulose. In addition, the maximum weight loss temperature in all treatments involving PEG was higher than in the case of the samples treated without PEG.

Theoretical study on the pyrolysis process of POSS nanocomposites based on the molecular vibration frequency

Identifying the factors that determine the thermal stability of polymer nanocomposites with inorganic fillers is vital. This study investigates how the modulation of polyhedral oligomeric silsesquioxanes (POSSs) affects the polymer-chain thermodynamics, using a multiscale analysis that integrates reactive molecular dynamics, first-principles calculations, and classical vibrational dynamics. The intramolecular energy transfer mechanism depending on the polymer-chain vibration frequency and covalent structure was analyzed for the entire pyrolysis process. The results revealed that the low-frequency vibration of POSS is key for the superior nanocomposite thermal stability. The dual frequency of the C–Si stretching mode directly contributes to the collection and dissipation of the thermal energy contained in the crosslinked polymer chain. The ability to block exothermic reaction pathways under pyrolysis conditions was also identified. This result elucidates the mechanism by which inorganic fillers perturb the thermodynamics and thermochemistry of polymer matrices as energy transfer within molecular chains.

Water-Soluble Nanocomposites Containing Co3O4 Nanoparticles Incorporated in Poly-1-vinyl-1,2,4-triazole.

New water-soluble nanocomposites with cobalt oxide nanoparticles (Co3O4NPs) in a poly(1-vinyl-1,2,4-triazole) (PVT) matrix have been synthesized. The PVT used as a stabilizing polymer matrix was obtained by radical polymerization of 1-vinyl-1,2,4-triazole (VT). The polymer nanocomposites with Co3O4 nanoparticles were characterized by ultraviolet-visible, Fourier-transform infrared spectroscopy, atomic absorption spectroscopy, transmission electron microscopy, dynamic light scattering, gel permeation chromatography, and simultaneous thermogravimetric analysis. The resulting polymer nanocomposites consist of spherical isolated cobalt nanoparticles with a diameter of 1 to 13 nm. The average hydrodynamic diameters of macromolecular coils are 15-112 nm. The cobalt content in nanocomposites ranges from 1.5 to 11.0 wt.%. The thermal stability of nanocomposites is up to 320 °C.

Enhanced electron radiation shielding composite developed by well dispersed fillers in PDMS polymer

This study reports a novel shielding material against high energy electron beam, where bismuth oxide (Bi2O3) and multiwalled carbon nanotube (MWCNT) nanoparticles added in a polymer matrix can solid electron beam radiation several times more efficient than aluminum with the same areal density. The polymer nanocomposites were prepared by dispersing nanoparticles in polydimethylsiloxane (PDMS) with a simple one-step fabrication process, in five areal densities (0.5, 1, 1.5, 3, and 5 g/cm2). All the samples were irradiated by 9, 12, 16, and 20 MeV electron beam. The prepared PDMS/CNT/BiO (CNT and BiO are the shorten name of fillers for coding the samples) showed better electron shielding ability than aluminum (Al) for any areal density. The weight advantageous of nanocomposite over aluminum was calculated up to 36 wt% for same attenuation efficiency. The thermal stability of nanocomposites up to 415 °C, as well as the tensile strength of up to 4.7 MPa, exhibited the high potential of developed samples for high energy electron beam shielding in medical and aerospace applications.

Preparation of thermally stable organic-inorganic hybrid nanocomposites from chemically functionalized oxidized graphite by in situ catalytic oxidative decarboxylation

ABSTRACT In this study, the preparation of thermally stable organic-inorganic hybrid nanocomposites from chemically functionalized oxidized graphite is carried out by in-situ catalytic oxidative decarboxylation of 3,5-dinitrobenzoic acid (reactant) in the presence of potassium persulfate (oxidant), silver nitrate (catalyst) and graphite (support) under thermal or microwave conditions. The effects of heat transfer and dosages of reactant, catalyst and oxidant on the crystalline structure and the morphology of nanocomposites are studied in detail. The prepared nanocomposites are characterized by EDS, elemental mapping, FE-SEM, FT-IR and XRD. The thermal stability of nanocomposites is examined by TGA and DSC. EDS shows that nanocomposites are composed of C, O, N, S, K and Ag elements. FT-IR exhibits that the graphitic layers in nanocomposites are mainly oxidized and functionalized with carboxyl, carbonyl, hydroxyl, epoxy, sulfate, nitrate and nitroaryl groups. Addition of nitroaryl groups to nanocomposites is also supported by an increase found in their C and N contents. XRD demonstrates the coexistence of both oxidized amorphous carbon and graphite in combination with different levels of organic and inorganic phases. The prepared nanocomposites show good thermal stability. The total area of the DSC curve in these nanocomposites compared to graphite is enhanced.

Exploring the optical and structural properties of chromium (Cr)-doped polyaniline

In this present work, a Cr-Doped Polyaniline [Cr-PANI-CNT] nanocomposite using the chemical polymerization method is synthesized, where ammonium persulphate was used as an oxidant in an acidic (HCl) medium. The optical properties of both CNTs and PANI with Cr were investigated using Fourier Transform Infrared Spectroscopy (FTIR), and the morphological study of the nanocomposite was performed with the help of FESEM and TEM analysis. Expanding on this, our investigation into the Cr-Doped Polyaniline [Cr-PANI-CNT] nanocomposite's optical properties via FTIR included a detailed examination of the interaction between Carbon Nanotubes (CNTs) and PANI doped with Cr. This analysis not only provided insights into the chemical bonding and structural changes but also shed light on the nanocomposite's potential applications in optoelectronic devices. Furthermore, our comprehensive morphological study using FESEM and TEM analysis allowed us to delve into the nanocomposite's structural characteristics and surface morphology at the nanoscale level. These insights are crucial for understanding the nanocomposite's physical properties and its suitability for various technological applications, such as sensors, energy storage devices, and catalysis. This study explored the electrical conductivity of Cr-Doped Polyaniline [Cr-PANI-CNT] nanocomposite through techniques like electrical conductivity measurements and cyclic voltammetry. These analyses revealed insights into its charge transport mechanisms and potential applications in electronics like field-effect transistors and conductive coatings. Additionally, Thermogravimetric Analysis (TGA) showcased the nanocomposite's thermal stability, making it suitable for hightemperature uses. These findings enhance our understanding and open avenues for its optimized utilization in various advanced technological domains.

TG/MS/FTIR study on thermal degradation process of clay mineral–polysiloxane nanocomposites

Clay-polymer nanocomposites (CPNs) are an important group of materials that are currently receiving increasing attention. The study of the properties of new CPNs is vital, as it facilitates a deeper understanding of their applicability. This study assessed for the first time the thermal stability of clay-polysiloxane nanocomposite as well as their degradation mechanism under an inert atmosphere with the use of the TG/MS/FTIR (simultaneous mass spectrometry and Fourier transform infrared spectroscopy of off-gases from a thermogravimetric analyzer) technique. Organo-montmorillonite (organo-Mt) nanofiller was introduced at different amounts (0, 1, 2, 4, and 8 wt% in relation to the weight of the polymer matrix) into the structure-controlled polysiloxane network. The polysiloxane matrix was obtained by cross-linking poly(methylhydrosiloxane) with poly(dimethylsiloxane) terminated by vinyldimethylsiloxy groups at both ends. This cross-linking was carried out through a hydrosilylation reaction with an equimolar ratio of Si–H and Si-CH=CH2 groups, in the presence of Karstedt's catalyst. Along with an increased amount of organo-Mt, a deterioration in nanocomposites thermal stability, with an increase in the number of thermal decomposition steps, and changes in the degradation mechanism of polysiloxane matrix were observed. The presence of organo-Mt mainly affected the redistribution of bonds at the silicon atoms during the thermolysis of the studied materials. Regardless of the amount of the mineral nanofiller added, the nanocomposites had a similar residual mass remaining after pyrolysis of the studied CPNs at 1000 °C, which was much lower than that of the initial polysiloxane network.

Microstructure-Dependent Thermal Stability of Super-Tetragonal Nanocomposite Films through In Situ TEM/EELS Study.

Smart microstructure design in nanocomposite films allows us to tailor physical properties such as ferroelectricity and thermal stability to broaden applications of next-generation electronic devices. Here, we study the thermal stability of self-assembled PbTiO3 (PTO)/PbO nanocomposite films with nano-spherical and nanocolumnar microstructures by utilizing an environmental transmission electron microscopy (TEM) combined with electron energy loss spectroscopy (EELS). The real-time study reveals that the microstructure-dependent interphase strain has an effect on the stabilization of the tetragonal phase. Compared to the nano-spherical configuration, the nanocomposite film with the nanocolumnar microstructure can maintain the giant tetragonality of ∼1.20 up to 450 °C, and the tetragonal phase is predicted to be stable at elevated temperatures > 600 °C. Moreover, the temperature-dependent EELS further demonstrates the sensitivity of the chemical bonding of Pb and Ti with O to the PTO lattice distortion, correlating the structural variation and electronic properties at different temperatures. Such in situ heating TEM study provides insights into the thermal stability of nanocomposites with different microstructures and facilitates the advancement of power electronics applications in harsh environments.

ТЕРМОСТОЙКОСТЬ ПОСАДОК ПОДШИПНИКОВ КАЧЕНИЯ, ВОССТАНОВЛЕННЫХ ЭЛАСТОМЕРНЫМИ НАНОКОМПОЗИТАМИ

The heat resistance of the polymer material for restoring bearing fits is its most important operational property. The thermal stability of nanocomposites when filling elastomers with nanoparticles varies ambiguously and depends on the type of rubber that is the basis of the elastomer. To restore bearing fits, fillers, in addition to copper nanoparticles, use aluminum nanoparticles, as well as carbon nanotubes in nanocomposites. The effect of carbon nanotubes and aluminum nanoparticles on the heat resistance of elastomers was investigated. The change in the deformation-strength properties of the F-40S elastomer and nanocomposites based on it before and after high-temperature aging was experimentally studied. Composition No. 1: F-40S elastomer – 100 mass parts, Taunit carbon nanotubes – 0.1 mass parts. Composition No. 2: F-40S elastomer – 100 mass parts, aluminum nanopowder – 0.075 mass parts. Samples were made in the form of polymer films. Thermal aging of the samples was carried out under conditions of limited oxygen access to air. The heat resistance of the nanocomposite of composition No. 1, in comparison with the F-40S not filled with elastomer, has increased. The aging coefficient of the nanocomposite in strength, in comparison with the unfilled elastomer, increased by 1.2 times, and in terms of deformation, it increased by 1.38 times. The aging coefficient of the nanocomposite composition No. 2 in strength, in comparison with the unfilled elastomer, increased by 1.17 times, and in terms of deformation, it increased by 1.2 times, which confirms the increase in its heat resistance. Experimental studies have established that the Townit-M carbon nanotubes and aluminum powder nanoparticles are inhibitors of the elastomer thermal oxidation process F-40S and therefore increase the heat resistance of nanocomposites based on it.

Thermal stability and rheological properties of PMMA/B2O3 nanocomposites synthesised by melting method

ABSTRACT Nano boron oxide (B2O3) was firstly produced from granular B2O3 by ball milling under cryogenic conditions. Then, PMMA/B2O3 nanocomposites were synthesized by melting method and then characterized. Finally, the rheological properties of PMMA/B2O3 nanocomposite were investigated using a high pressure capillary rheometer. Brauner-Emmet-Teller (BET) surface area analysis showed that the surface area of B2O3 increased with cryogenic grinding. Transmission electron microscopy (TEM) images revealed that B2O3 particles were nano-sized. Scanning electron microscopy (SEM) images showed that the morphology changed with the increase of B2O3 amount. The thermal stability of nanocomposites was found to be better than PMMA. PMMA degraded in two steps, while nanocomposites degraded in one step. It was determined that the amount of residue increased with increasing amount of B2O3. Both PMMA and nanocomposites exhibited non-Newtonian shear thinning flow behavior. In addition, rheological data were found to be highly compatible with the Power Law model.

Use of synthetic wollastonite nanofibers in enhancing mechanical, thermal, and flammability properties of polyoxymethylene nanocomposites

AbstractThis study investigates the mechanical, thermal, and flammability properties of synthetic wollastonite nanofibers (SWN) reinforced polyoxymethylene (POM) nanocomposites. SWN has been added into the POM nanocomposites in the range of 0.5–3 phr via melt blending. The mechanical properties were investigated through tensile and impact tests with scanning electron microscopy and energy dispersive X‐ray analysis. The thermal characterization was performed by thermogravimetry analysis and differential scanning calorimetry. Flame retardancy of nanocomposites was studied through cone calorimetry analysis and limiting oxygen index test. The tensile strength of nanocomposites improved by 5.88% at 1 phr SWN content, whereas Young's modulus increased with increasing content. The thermal stability of nanocomposites was enhanced as indicated by the higher initial degradation temperature, which rose about 22°C at 1 phr SWN content. The POM/SWN nanocomposites exhibited better mechanical strength despite their lower crystallinity due to the substantial reinforcing effect of SWN. The flame retardancy of nanocomposites improved, as indicated by the reduction of peak heat release rate from the cone calorimetry test. This study shows that SWN has simultaneously enhanced the mechanical strength, thermal stability, and flame retardancy of POM nanocomposites and has the potential in automotive applications.

Graphene nanoplatelets reinforced Polyamide-11 nanocomposites thermal stability and aging for application in flexible pipelines

Novel nanocomposites of polyamide-11 (PA11) reinforced with commercial graphene nanoplatelets (GNP) in amounts of 1.0, 2.5, and 5.0 wt.% were prepared and characterized for their thermal stability and aging performance. The processing of the nanocomposites was carried out by mixing PA11 in the molten state employing a double screw mini-extruder at 200 °C under 60 rpm screw speed, with a residence time of 7 min. The incorporation of GNP increased the thermal stability of PA11, particularly in the amount of 1.0 wt.%, as observed by thermogravimetric analysis. X-ray diffraction indicated that the composites' crystallinity increased with 1.0 and 2.5 wt.% of GNP. Evidence of agglomerates formation in the sample with 5.0 wt.% of GNP suggests it to be less dispersed in the PA11 matrix and associated with reduction in crystallinity. The dynamic mechanical analysis showed that GNP promoted an increase in the storage and loss moduli. The increase of GNP in the PA11 matrix enhanced the water contact angle and, therefore, provided greater hydrophilicity of the nanocomposite. The GNP reinforcement prevents the decrease in the molar mass of PA11, estimated by the corrected inherent viscosity (CIV) measured with aging time into water at 85 °C, when compared to the performance of neat PA11. All nanocomposites had CIV values above 1.20 dL/g before and after the aging test. Therefore, using the lowest GNP content of 1.0 wt.% proved to be the more efficient for application in flexible oil/gas pipelines.

Ballistic performance of boron carbide nanoparticles reinforced ultra-high molecular weight polyethylene (UHMWPE)

Ultra-high molecular weight polyethylene (UHMWPE) is well known for its remarkable mechanical properties including excellent ballistic performance. These properties might be further improved by reinforcement fillers, especially nanoparticles (NPs). In the present work, UHMWPE is incorporated with 0.01, 0.05 and 0.1 wt% of boron carbide (B4C) NPs by twin-screw extrusion at 200 °C. These nanocomposites are characterized by high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) and then, for the first time, ballistic tested with 0.22 caliber ammunition. HRTEM images reveal B4C NPs with sizes in the range of 10–55 nm. SEM disclosed uniform incorporation of 0.01 and 0.05 wt% B4C NPs. The nanocomposites crystallinity index, obtained by XRD, remained practically constant (44–49%) but significantly lower than the neat UHMWPE (66%). A slight decrease in the nanocomposite's thermal stability was shown by TGA, while no significant changes were found by DSC as compared to the neat UHMWPE. The DMA properties of all nanocomposites were improved. In particular, the storage modulus of the 0.05 wt% B4C nanocomposite increased by 89% compared to neat UHMWPE. The ballistic result of the 0.05 wt% B4C nanocomposite showed the lowest bullet penetration depth and confirmed its advantage for personal armor application.

Influence of surface functionalization of ceramic nanofibers on morphological, physical and mechanical properties of unsaturated polyester nanocomposites

Alumina nanofibers at 0.25wt%, 0.5wt%, 0.75wt%, and 1wt% concentration were used to modify unsaturated polyester resin. Additionally, vinyl silane treated alumina nanofibers were used at the same concentrations and were compared to pristine alumina nanofibers. The SEM images showed a variation in the surface morphology when alumina nanofibers and the BET measurement showed surface area increase from 111 m2/g to 122 m2/g when nanofibers were treated with silane agent. The dispersion of alumina nanofibers into the host unsaturated polyester resin was successfully achieved by three roll mill dispersion. The TEM images showed good dispersion of alumina nanofibers in polyester resin. Although pristine nanofibers showed greater agglomeration at 1wt% concentration, the effect of agglomeration was reduced in the 1wt% concentration. The weight loss measurements from TGA showed that the thermal stability of nanocomposites increased with addition of nanofibers and the lower onset degradation temperature can be tailored to improve by a maximum of 5.5% for silane treated nanofiber. Viscosity and contact angle which are key factors affecting the processability has seen to be positively altered by silane treatment. Additional tensile, flexural, and Izod impact properties were evaluated for the nine material systems and the properties were summarized.