High‐performance flexible epoxy/ZnO nanocomposites with enhanced mechanical and thermal properties

Flexible epoxy/ZnO nanocomposites were prepared using different loadings of ZnO nanoparticles (NPs) and nanotubes (NTs) via in situ curing of epoxy with polyoxyethylene diamines (ED₆₀₀). ZnO precursor was synthesized via precipitation method and ZnO NPs with an average size of 25 nm were used in the preparation of the nanocomposites. ZnO NTs with an average outer diameter, length of 200 nm and 2.4 µm respectively, were prepared by the wet method (hydrothermal method). The morphology, structure, and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and thermo‐gravimetric analysis (TGA). The effect of morphology and content of nano‐ZnO materials on the thermal and mechanical properties of flexible epoxy was studied. In addition, the hardness and indentation depth were calculated by means of nanoindentation. Results showed that the mechanical and thermal properties of flexible epoxy were enhanced by incorporation of ZnO nanostructure into the polymer matrix. POLYM. ENG. SCI., 57:932–946, 2017. © 2016 Society of Plastics Engineers     

Effective methodology for the production of novel nanocomposite films based on poly(vinyl chloride) and zinc oxide nanoparticles modified with green poly(vinyl alcohol)

Ultrasonic irradiation and solution dispersion methods were used to organize transparent worthwhile poly(vinyl chloride) (PVC) nanocomposite (NC) films which contain different amounts of modified zinc oxide nanoparticles (NP)s. First, modification of ZnO NPs was accomplished by biocompatible poly(vinyl alcohol) (PVA) to increase NCs compatibility and dispersity in the PVC matrix. The investigation followed by the fabrication and characterization of PVC/ZnO‐PVA NCs which obtained via fast and facile ultrasonication irradiation. The measurements of X‐ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and field emission scanning electron microscopy were used for the characterization of properties, structure and morphology of the obtained NPs and their NCs. Furthermore, thermal and optical properties of the resulting NCs were also carried out by thermogravimetric analysis, ultraviolet‐visible transmission, and absorption spectra. Morphology results demonstrate well‐dispersed characteristics of ZnO‐PVA NPs incorporated in the PVC matrix which resulted from modification. Also, modified ZnO NPs enhanced mechanical properties of prepared NC films. Prepared NCs could be categorized as self‐extinguishing materials on the basis of the limiting oxygen index values. POLYM. COMPOS., 38:1800–1809, 2017. © 2015 Society of Plastics Engineers     

Mechanical properties,flame retardancy,and smoke suppression of lanthanum organic montmorillonite/poly(vinyl chloride) nanocomposites

A dimethyl dioctadecyl ammonium chloride modified organic montmorillonite (OMMT_‐I.44P)/poly(vinyl chloride) (PVC) nanocomposite and anionic‐surfactant‐modified lanthanum organic montmorillonite (La‐OMMT)/PVC nanocomposites (with three different anionic surfactants for the La‐OMMTs) were prepared via melt‐intercalation technology. The effects of the La‐OMMTs and OMMT_‐I.44P on the mechanical properties, flame retardancy, and smoke suppression of PVC were studied. X‐ray diffraction characterization showed that the La‐OMMTs were exfoliated in the PVC matrix. The mechanical properties of the nanocomposites were enhanced by the incorporation of the La‐OMMTs. Cone calorimetry and gas chromatography–mass spectrometry analyses indicated that the incorporation of the La‐OMMTs enhanced the flame retardancy and smoke suppression of the PVC nanocomposites. Scanning electron microscopy photos further showed that the residual char surfaces of La‐OMMT/PVC were all intact and, thus, provided better barriers to energy and smoke transport. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43951.     

Effect of zinc oxide nanoparticles as cure activator on the properties of natural rubber and nitrile rubber

Zinc oxide (ZnO) nanoparticles were synthesized by homogeneous precipitation and calcination method and were then characterized by transmission electron microscopy and X‐ray diffraction analysis. Synthesized ZnO was found to have no impurity and had a dimension ranging from 30–70 nm with an average of 50 nm. The effect of these ZnO nanoparticles as cure activator was studied for the first time in natural rubber (NR) and nitrile rubber (NBR) and compared with conventional rubber grade ZnO with special reference to mechanical and dynamic mechanical properties. From the rheograph, the maximum torque value was found to increase for both NR and NBR compounds containing ZnO nanoparticles. ZnO nanoparticles were found to be more uniformly dispersed in the rubber matrix in comparison with the conventional rubber grade ZnO as evident from scanning electron microscopy/X‐ray dot mapping analysis. The tensile strength was observed to improve by 80% for NR when ZnO nanoparticles were used as cure activator instead of conventional rubber grade ZnO. An improvement of 70% was observed in the case of NBR. The glass transition temperature (T_g) showed a positive shift by 6°C for both NR and NBR nanocomposites, which indicated an increase in crosslinking density. The swelling ratio was found to decrease in the case of both NR and NBR, and volume fraction of rubber in swollen gel was observed to increase, which supported the improvement in mechanical and dynamic mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Influence of incorporation of ZnO nanoparticles and biaxial orientation on mechanical and oxygen barrier properties of polypropylene films for food packaging applications

In this work, the effect of zinc oxide (ZnO) concentration and shape on processing and properties of new biaxially oriented polypropylene (BOPP)‐ZnO nanocomposites was studied. The use of spherical nanoparticles and nanorods was expected to differently influence the properties of the final material. Films of isotactic polypropylene prepared with different ZnO incorporation were biaxially oriented under conditions of temperature and strain rate that were similar to those encountered in a commercial film process. Scanning electron microscopy analysis was performed to visualize the dispersion degree of the ZnO nanoparticles in the polymer matrix and to observe the surface and the orientation of the elongated nanoparticles. Furthermore, the prepared ZnO‐BOPP nanocomposites were evaluated for both mechanical and oxygen barrier property enhancement. A good combination of mechanical and oxygen barrier properties was obtained for the ZnO‐BOPP films. This result makes the ZnO‐BOPP nanocomposite a proper material for applications such as food packaging. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and performance of CdS-hyperbranched poly(arylene ether ketone) nanocomposite materials

A new kind of CdS-hyperbranched poly (arylene ether ketone) (HP-PAEK) nanocomposite was prepared in dimethylformamide solution by carboxylic-functionalised HP-PAEK as surface modifier without ligand exchange. The CdS/HP-PAEK nanocomposites were characterised through ultraviolet–visible and photoluminescence spectroscopy. The experimental results of photoluminescence measurement showed that the nanocomposites had obvious luminescence properties. The formation and size of CdS quantum dots were determined by Fourier transform infrared spectroscopy and transmission electron microscopy. The thermal properties of CdS/HP-PAEK nanocomposites were analysed by differential scanning calorimetry and thermogravimetric analysis. Owing to the introduction of CdS nanoparticles, the nanocomposites exhibited excellent heat resistance and higher fluorescent quantum efficiency.     

Morphology and properties of PVC/clay nanocomposites via in situ emulsion polymerization

PVC/Na⁺–montmorillonite (MMT) nanocomposites were prepared via a simple technique of emulsion polymerization at several different MMT clay concentrations. X‐ray diffraction and transmission electron microscopy studies revealed the formation of a mixture of intercalated and exfoliated nanostructure. Tensile testing results showed that the tensile modulus of the nanocomposites increased with the addition of clay, while the tensile strength decreased little. The notched impact strength of the nanocomposites was also improved. For systems containing clay in the range of 2.1 to 3.5 wt %, the impact strength was almost two times as large as that of pure PVC. However, those mechanical properties began to decrease with the continuously increasing amount of clay. The fracture surface of pure PVC and the nanocomposites was observed by scanning electron microscope. Thermal properties of the nanocomposites were found to increase as a result of clay incorporation. The glass transition temperatures of the PVC/clay nanocomposites were nearly identical to that of pure PVC. The Vicat softening points exhibited a progressively increasing trend with the clay content added. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 277–286, 2004     

Thermal,thermomechanical, and morphological characterization of poly(vinyl chloride) (PVC)/ZnO nanocomposites: PVC molecular weight effect

Poly(vinyl chloride) (PVC)‐based nanocomposites containing 2 wt% zinc oxide (ZnO) nanoparticles were prepared by solution casting and the effect of the PVC molecular weight (MW) on the morphology, thermal properties, and thermogravimetric behavior was studied. The addition of ZnO nanoparticles to PVCs of different MWs increased the glass transition temperature (T_g) of the resulting nanocomposites, the extent of which was dependent upon the MW of the PVC matrix. The nanocomposite samples exhibited broadened transition zones as compared with their unfilled PVC matrices. The extent of transition zone broadening was also controlled by the MW of the PVC matrix in the nanocomposites. In the absence of ZnO nanoparticles, the increase in MW of PVC had no effect on the breadth of the transition zone. The TGA results showed that the incorporation of ZnO nanoparticles into PVC matrices of different MWs accelerated the first stage weight loss via the nanoparticle catalytic effect through removal of HCL from the polymeric chains. The presence of ZnO nanoparticles lowered the second stage weight loss, and the char yield obtained for nanocomposites samples was significantly greater than that obtained for neat PVC samples. At low MWs, the presence of ZnO nanoparticles had no effect on the first stage of thermal degradation process. The presence of ZnO nanoparticles in the matrix in different nanocomposites was revealed by SEM observations, and the EDX analysis demonstrated a progressive improvement in the distribution and dispersion state of ZnO nanoparticles in the PVC‐based nanocomposites as the MW of PVC matrix gradually increased. J. VINYL ADDIT. TECHNOL., 25:E63–E71, 2019. © 2018 Society of Plastics Engineers     

The thermal,optical, flame retardant,and morphological consequence of embedding diacid‐capped ZnO into the recycled PET matrix

We extended our work to a fast and facile nanocomposites (NCs) manufacturing by incorporation of ZnO nanoparticles (NPs) on to a recycled poly(ethylene terephthalate) PET as a polymer matrix prepared by a dissolution/reprecipitation method. The surface of ZnO NPs was functionalized with synthesized optically active diacid containing alanine amino acid. Organo‐modified NPs which provided using solution blending technique through ultrasonic irradiation, were embedded into recycled PET. PET@ZnO/DA NCs containing different loadings of functionalized NPs (1, 3, 5 wt %) were investigated by thermal gravimetric analysis, field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy and UV–visible spectroscopy. Morphological studies revealed uniformly dispersed ZnO/DA NPs in the polymer matrix. The crystalline nature of PET slightly improved as a function of the NPs concentration. Char yield in TGA and LOI values indicated that the obtained NCs were capable of exhibiting flame retardant properties. The NCs were found to exhibit more absorbance in the UV and visible region in compare to the neat PET. The effect of ultrasonication in different solvent on the morphology of the recycled polymer particle was also studied. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43433.     

The Change of Structural,Optical and Thermal Properties of a PVDF/PVC Blend Containing ZnO Nanoparticles

Nanocomposites consisting of a polyvinylidene fluoride (PVDF)/polyvinyl chloride (PVC) blend containing zinc oxide (ZnO) nanoparticles were prepared. The changes of the structural, optical and thermal properties of the PVDF/PVC blend before and after addition of ZnO were studied. The shift of intensity in IR bands suggested an interaction and compatibility between the blend and ZnO. The structural properties, crystallinity and grain size of the samples were studied using X-ray diffraction. The average grain size was approximately 16 nm confirmed by TEM observations. The X-ray peak positions of ZnO in doped samples were located in the same positions as those of pure ZnO indicating the crystal structure of ZnO was not altered by its incorporation into PVDF/PVC. The estimated values of the optical energy gap from UV/Vis spectra for indirect transition decrease with increasing ZnO due to charge transfer between PVDF/PVC and ZnO nanoparticles. The thermogravimetric analysis curves showed nearly identical behaviors for all samples. Samples that contained ZnO exhibited less weight loss compared to the pure blend attributed to crosslinking formation between the blend and ZnO. Transmission electron microscopy (TEM) images revealed that ZnO was uniformly distributed inside PVDF/PVC polymeric matrices and was superimposed on an amorphous background.     

A simple and environmentally friendly method for surface modification of ZrO2 nanoparticles by biosafe citric acid as well as ascorbic acid (vitamin C) and its application for the preparation of poly(vinyl chloride) nanocomposite films

In this investigation, poly(vinyl chloride) (PVC) as one of the most important thermoplastic polymer was combined with different concentrations (4, 8, and 12 wt%) of ZrO₂ nanoparticles (NPs) with the purpose of preparing novel nanocomposites (NCs). To prevent aggregation and obtain homogeneous dispersion of the NPs in the polymer matrix, surface modification of ZrO₂ was performed by biosafe, biodegradable as well as biocompatible modifiers such as citric acid and ascorbic acid (vitamin C) due to their ability to form chelates with metal oxides. The effect of modified ZrO₂ on the properties of the PVC was studied by different techniques. The field emission scanning electron microscopy and transmission electron microscopy results indicated that the modified NPs were dispersed homogeneously in the polymer matrix. UV–Vis spectroscopy was used to study optical behaviors of the obtained NCs. Thermogravimetric analysis indicated that the thermal stability of the polymer was enhanced after incorporation with NPs. Finally, mechanical test was revealed that the NC films were more flexible when compared with the neat polymer. POLYM. COMPOS., 38:1756–1765, 2017. © 2015 Society of Plastics Engineers     

Effects of Nickel Oxide (NiO) nanoparticles on the performance characteristics of the jatropha oil based alkyd and epoxy blends

Plant oil based alkyd resin was prepared from jatropha oil and blended with epoxy resin. Subsequently, alkyd/epoxy/NiO nanocomposites with different wt % of NiO nanoparticles have been prepared by mechanical mixing of the designed components. The structure, morphology, and performance characteristics of the nanocomposites were studied by UV‐visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and universal testing machine (UTM). The alkyd/epoxy/NiO nanocomposites showed the gradual increase in thermal stability with increasing NiO content. With 3 wt % NiO content the tensile strength of the nanocomposite increased by 19 MPa (more than twofold) when compared with the pristine polymer. Limiting oxygen index (LOI) value of the nanocomposites indicate that the incorporation of NiO nanoparticles even in 1 wt % can greatly improves the flame retardant property of the nanocomposites. This study confirms the strong influence of NiO nanoparticles on the thermal, mechanical, and flame retardant properties of the alkyd/epoxy/NiO nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41490.     

Effect of Inorganic Silver Nanoparticles on Structural and Electrical Properties of Polyaniline/PVC Blends

Dodecylbenzenesulfonic acid (DBSA) doped polyaniline (PANDR) has been synthesized by redoping method. Inorganic silver nanoparticles were incorporated in THF solution of PANDR (PANDS) and then mixed with PVC solution to prepare PANDS/PVC nanocomposites. FTIR spectroscopy indicated that silver nanoparticles reside more close to imine nitrogen of PANDS. Transmission electron microscopy (TEM) confirmed the formation and dispersion of silver nanoparticles in polymer matrix having average size of ~20 nm. Incorporation of inorganic metal silver nanoparticles has improved the mechanical properties of nanocomposite films as compared to pure polymer blends. Addition of silver nanoparticles in the blends reduces the charge trapping centres and increases the conducting channels; as a result a decrease in the real part of impedance has been observed.     

Efficient Dispersion of Magnetite Nanoparticles in the Polyurethane Matrix Through Solution Mixing and Investigation of the Nanocomposite Properties

Recent studies on inorganic/polymer nanocomposites have shown enhancements in thermal, mechanical, and chemical properties over the neat polymer without compromising density, toughness, and processibility. When nanoparticles are incorporated into the polymer matrix, significant enhancements in thermal and mechanical properties of the nanocomposite are observed. The present study is focused on the preparation and characterization of nanosize magnetite-reinforced PU composites, which induces magnetic properties to a specific thermoplastic polyurethane elastomer. The nanocomposites are prepared and the effects of magnetite content on thermal, mechanical, and magnetic properties of the nanocomposites are evaluated. Ultrasonication was used to disperse the nanoparticles and break up any large clumps and aggregates and followed by mechanical mixing. The magnetic nanocomposites were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Characterization of the magnetic nanocomposite by FT-IR showed a successful incorporation of magnetite nanoparticles into the polymeric matrix. TGA and magnetometry of the magnetic nanocomposites revealed the amount of magnetite that was incorporated into the polymeric phase. Finally, the corresponding magnetization behavior of the nanocomposites was studied.     

Mechanical and UV absorption behavior of zinc oxide nanoparticles: reinforced poly(vinyl alcohol-<Emphasis Type="Italic">g</Emphasis>-acrylonitrile) nanocomposite films

In the present work PVA-g-PAN/ZnO nanocomposite films were prepared by free radical graft copolymerization of acrylonitrile on to PVA and subsequent in situ precipitation of ZnO nanoparticles into the polymer matrix. The films were characterized by FTIR, Raman spectroscopy, differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The size of the crystallites and extents of crystallinity were ascertained by X-ray diffraction (XRD) analysis. The SEM with energy dispersive X-ray analysis (EDX) showed that the ZnO nanoparticles were uniformly dispersed within the host grafted copolymer matrix. The transmission electron microscopy (TEM) results clearly indicated that the size of nanoparticles varied in the range 10–30 nm. The UV-absorption properties showed that the films were capable of absorbing more than 95% of UV radiations. Photoluminescence (PL) measurements revealed the presence of defects in the synthesized nanocomposite films. The mechanical properties of the PVA-g-PAN/ZnO nanocomposites such as microhardness and tensile strength were also studied.     

Enhancement of the thermal stability,mechanical properties and morphologies of recycled PVC/clay nanocomposites

Summary Recycled PVC/clay nanocomposites were prepared by melt mixing of recycled PVCs and modified clays. Characterization of the nanostructure of the nanocomposites was carried out using wide angle X-ray diffraction (WAXD) and transmission electron microscopy(TEM). In case of 10wt.%, the characteristic peak of modified clay was perfectly disappeared, because of aids of plasticizers as co-intercalator. Thermal stability was evaluated from the thermal decomposition behaviors and linear dimension changes by TGA and TMA system. Coefficients of thermal expansion of the nanocomposites were also observed from TMA analysis. Dynamic mechanical properties were evaluated using DMA system. The thermal and mechanical properties of the nanocomposites were improved simultaneously for varied clay loadings, 1,3,5,10wt.%, compared to recycled PVC. Especially, the storage modulus of the nanocomposites with 10wt.% clay loading was increased 11 times compared to that of recycled PVC.     

Dispersivity of modified ZnO and characterization of polyurethane/ZnO composites

The properties of inorganic nanoparticles/polymer composites depend on the dispersivity of nanoparticles in a polymer matrix. The effect of surface modification on the dispersivity of ZnO nanoparticles in a polyurethane (PU) resin matrix was investigated. The nanocomposites were characterized by scanning electron microscopy (SEM), thermogravimetric analysis, and X‐ray diffraction. The scanning electron micrographs show that ZnO nanoparticles (CDI–SA–APS–ZnO), which were modified by aminopropyltriethoxysilane (APS) and activated stearic acid (SA) by N,N′‐carbonyldiimidazole (CDI), can be homogeneously dispersed and had been encapsulated in the PU phase. The interfacial compatibility between ZnO nanoparticles and PU matrix was significantly improved by hydrophobically modifying ZnO nanoparticles with APS and SA. The tensile strength and elongation at break of PU/CDI–SA–APS–ZnO nanocomposites increased by 82 and 64% respectively, compared with the pure PU material. The thermal stability and ultraviolet‐shielding properties were also improved by incorporating ZnO nanoparticles into the PU matrix. POLYM. COMPOS., 35:237–244, 2014. © 2013 Society of Plastics Engineers     

Antibacterial Nanocomposite of Poly(Lactic Acid) and ZnO Nanoparticles Stabilized with Poly(Vinyl Alcohol): Thermal and Morphological Characterization

The effect of polyvinyl alcohol (PVA) as a surface coating agent on the antibacterial and thermal properties of polylactic acid (PLA)/ZnO nanocomposites prepared by melt blending was investigated. The ZnO nanoparticles were coated and stabilized with PVA using a solvothermal method. Nanocomposites were prepared with different ZnO nanoparticle content: 1, 3 and 5 wt.%. Electron transmission microscopy and Fourier transform infrared spectroscopy showed the presence of a layer around the nanoparticles and the interaction between nanoparticles and PVA, respectively. DSC analysis revealed that the thermal properties of the nanocomposites were not affected by the coating of ZnO nanoparticles with PVA. The PLA/ZnO nanocomposites with coated nanoparticles presented better antibacterial activity than those containing uncoated nanoparticles.     

Influence of surface modification of zinc oxide nanoparticles on thermal behavior and hydrophilic property of PET–PEG composites

Zinc oxide (ZnO) nanoparticles were successfully prepared by a one‐step precipitation reaction in an aqueous solution of zinc acetate and sodium hydroxide with stearic acid (SA) as the modifying agent. Hydrophilic composites of poly(ethylene terephthalate) (PET), poly(ethylene glycol), and ZnO nanoparticles were prepared further by in situ polymerization. The surface modification of ZnO and the microstructure and properties of prepared nanoparticles were investigated by relative contact angle measurements (CA), Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy, and thermogravimetric analysis (TGA). Measurements of CA and XRD indicated that the surface‐treated ZnO was hydrophobic and had a significant improvement in crystallinity with SA. Compared with the nanocomposites filled with the pure ZnO, the modified ZnO exhibits a better dispersion in PET–PEG matrix. TGA results showed that the presence of modified ZnO nanoparticles can improve the thermal stability of PET–PEG matrix. CA and low field nuclear magnetic resonance methods were used to investigate the hydrophilic behavior of nanocomposites. The results revealed that modified nanoparticles had a positive effect on the bound water absorption. A simple model for the interactions between ZnO, SA, and PET–PEG matrix was proposed. POLYM. COMPOS., 37:1830–1838, 2016. © 2015 Society of Plastics Engineers     

Electrical properties and thermal degradation of poly(vinyl chloride)/polyvinylidene fluoride/ZnO polymer nanocomposites

In this work, polymer nanocomposites consisting of a poly(vinyl chloride) (PVC) and polyvinylidene fluoride (PVDF) polymer network with ZnO nanoparticles as a dopant were prepared by solution casting. An XRD study of the PVC/PVDF/ZnO polymer nanocomposites shows predominantly sharp and high intensity peaks. However, the intensity and sharpness of the XRD peaks decreases with further increment in loading of ZnO (wt%), which reveals a proper intercalation of ZnO nanoparticles within the PVC/PVDF polymer system. Fourier transform infrared spectroscopy has been used to verify the chemical compositional change as a function of ZnO nanoparticle loading. TGA analysis clearly describes the thermal degradation of the pure polymer and polymer nanocomposites. The complex dielectric function, AC electrical conductivity and impedance spectra of these nanocomposites were investigated over the frequency range from 10 Hz to 35 MHz. These spectra were studied with respect to the Wagner ? Maxwell ? Sillars phenomenon in the low frequency region. Nyquist plots of the PVC/PVDF/ZnO nanocomposites were established from impedance measurements. The temperature‐dependent DC ionic conductivity obtained from the Nyquist plots follows Arrhenius behaviour. © 2016 Society of Chemical Industry