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1.
Graphene oxide (GO) incorporated ultra-high molecular weight polyethylene (UHMWPE) nanocomposites were prepared by encapsulating GO by UHMWPE in an aqueous media via high-shear mixing, which were subsequently dried and compression molded. Morphological characterizations via scanning electron microscopy revealed the intercalation of UHMWPE chains in the graphitic stacks corresponding to GO. Further, dielectric permittivity of UHMWPE/GO nanocomposite of 1 wt% GO showed a drastic increase (~61) as compared to pure UHMWPE (~2) due to an enhanced interfacial polarization. A significantly higher value of remnant polarization (~10 nC/cm2) and coercive field (~3 kV/cm) was observed in UHMWPE/GO nanocomposite of 1 wt% GO, which showed a strong hysteresis loop of polarization versus electric field plot as compared to pure UHMWPE, which displayed a very weak hysteresis loop. The piezoelectric coefficient (d33) of ~9.5 pm/V was estimated in UHMWPE/GO nanocomposite of 1 wt% GO via piezoresponse force microscopy. Nanocomposite sensor devices were also fabricated and piezoelectric output voltage of ~6 V was recorded in UHMWPE/GO nanocomposite of 1 wt% of GO. We report here for the first time the unique ferroelectric and piezoelectric properties displayed by UHMWPE/GO nanocomposites.  相似文献   

2.
Poly(methyl methacrylate) (PMMA)/SiO2 nanocomposites were prepared by in situ suspension polymerization. Two types of modified methods were used to modify nano‐SiO2: one was modification by γ‐methacyloxypropyl trimethoxy silane (KH570) and lauryl alcohol (12COH) while the other was grafting PMMA onto the surface of KH570 treated SiO2. Transmission electron microscopy (TEM) and Fourier transformed infrared (FTIR) were used to characterize the structures of the nanocomposites. The influence of synthetic conditions, for instance, surface modification, initial SiO2 contents and reaction temperature, on the microsphere's size and molecular weight of the extracted PMMA were studied by gel permeation chromatograph (GPC) and optical microscopy (OM) in details. Thermal property of the nanocomposites was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicate that the presence and content of SiO2 have a vital effect on the shape and size of the nanocomposite microspheres, as well as molecular weight of the extracted PMMA. Grafting polymer to the surface of SiO2 is an effective way for the purpose of effective in situ suspension polymerization. Compared to pure PMMA, the thermal properties of the nanocomposites were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

3.
In this article, the surface of SiO2 nanoparticles was modified by silane coupling agent N‐(2‐aminoethyl)‐γ‐aminopropylmethyl dimethoxy silane. The bismaleimide nanocomposites with surface‐modified SiO2 nanoparticles or unmodified SiO2 nanoparticles were prepared by the same casting method. The tribological performance of the nanocomposites was studied on an M‐200 friction and wear tester. The results indicated that the addition of SiO2 nanoparticles could decrease the frictional coefficient and the wear rate of the composites. The nanocomposites with surface‐modified SiO2 nanoparticles showed better wear resistance and lower frictional coefficient than that with the unmodified nanoparticles SiO2. The specific wear rate and the steady frictional coefficient of the composite with 1.0 wt % surface‐modified SiO2 nanoparticles are only 1.8 × 10?6 mm3/N m and 0.21, respectively. The dispersion of surface‐modified SiO2 nanoparticles in resin matrix was observed with transmission electron microscope, and the worn surfaces of pure resin matrix and the nanocomposites were observed with scanning electron microscope. The different tribological behavior of the resin matrix and the filled composites should be dependent on their different mechanical properties and wear mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

4.
Montmorillonite (MMT)/low-density polyethylene (LDPE) nanocomposites have excellent partial discharge resistance and electrical tree resistance compared with pure LDPE. However, the MMT/LDPE nanocomposites have low breakdown strength due to the poor compatibility between nano-MMT and LDPE. In order to improve the breakdown strength of the MMT/LDPE composites without changing the LDPE matrix, an MMT/SiO2/LDPE multielement composite was prepared by melt blending, and its breakdown strength and electrical tree resistance properties were investigated. The results show that the MMT/SiO2/LDPE multielement composite has excellent breakdown strength and electrical tree resistance properties compared with the MMT/LDPE composite. The reasons for the excellent insulation properties of the MMT/SiO2/LDPE multielement composites were analyzed by exploring the effects of MMT and SiO2 on the microstructure and trap characteristics of LDPE. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47364.  相似文献   

5.
In this article, a new type of soluble polyester/silica (PE/SiO2) hybrid was prepared by the ultrasonic irradiation process. Surface modification of SiO2 was conducted using coupling agent γ‐glycidyloxypropyltrimethoxysilane (GOTMS) under ultrasonic irradiation. The structures of the modified hybrid nanocomposites were identified with a Fourier‐transform infrared spectroscopy (FT‐IR), whereas the size of the SiO2 in PE was characterized with a scanning electron microscope (SEM). SEM results indicated the formation and dispersion of nanometer scale size of inorganic domains inside the PE matrix due to the introduction of modified SiO2 and the interactions between organic and inorganic phases. The size of SiO2 particles in the modified system was about 25 nm. The transmission electron microscope (TEM) analysis showing the well‐dispersed nanosized titania nanoparticles (NPs). The densities and solubilities of the PE/SiO2 hybrids were also measured. Furthermore, thermal stability, residual solvent in the membrane film, and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). Moreover, their mechanical properties were also characterized. It can be observed that the Young's moduli (E) of the hybrid films increase linearly with the silica content. The results obtained from gas permeation experiments showed that adding SiO2 to the PE membrane structure increased the permeability of the membranes. POLYM. ENG. SCI., 59:E237–E247, 2019. © 2018 Society of Plastics Engineers  相似文献   

6.
Graphene oxide (GO) and silicon dioxide (SiO2) nanoparticles have been hybridized for improving the mechanical and dynamic mechanical properties of nitrile rubber (NBR). SiO2 nanoparticles were homogeneously dispersed on the surface and between layers of GO, and the new hybrid nanoparticles formed (GO/SiO2) had better thermal stability than GO. To evaluate the mechanical properties, GO/SiO2/NBR nanocomposites were prepared by solution blending and mechanical solution methods. It was observed that tensile strength increased in a larger grade in GO/SiO2/NBR nanocomposites than that in GO/NBR and SiO2/NBR nanocomposites, while the elongation at break only changes smoothly. Moreover, dynamics measurements also indicated that the elasticity increased after adding GO/SiO2 hybrid nanoparticles in NBR. From morphology's analysis of GO/SiO2/NBR and GO/NBR nanocomposites, it is was conclude that the hybridization of the GO/SiO2 was the determining factor for the reinforcement of the mechanical properties and elasticity of the NBR. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46091.  相似文献   

7.
The production of traditional cellulose paper not only consumes lots of timber, but also brings about some environmental issues. Therefore, it is being increasingly replaced by synthetic paper. In this study, ultrahigh molecular weight polyethylene (UHMWPE)/SiO2 synthetic paper with high application performance was prepared by the thermally induced phase separation method using mineral oil as diluent. The corresponding properties of synthetic paper, including surface morphology, overall porosity, tensile strength, thermal stability, acid and alkali resistance, whiteness, and inkjet print effect were investigated respectively. The results show that the overall porosity of UHMWPE/SiO2 synthetic paper is above 45%, and the tensile strength exceeds 4.3 MPa. UHMWPE/SiO2 synthetic paper also presents light weight, as well as good resistance to heat, acid and alkali. Meanwhile, the average whiteness of the samples is up to 91.8%. The sample K‐50, which contains 31.5 wt % SiO2, takes on the best print performance caused by its dense surface and higher SiO2 content. It is indicated that UHMWPE/SiO2 synthetic paper has good market prospects in the color printing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41529.  相似文献   

8.
In this work, a compatibilizer (UHMWPE‐g‐GO) with large specific surface was prepared from graphene oxide (GO) and ultra‐high molecular weight polyethylene (UHMWPE). First, GO was modified by 2, 3‐epoxypropyltrimethylammonium chloride (GTA), subsequently grafted with UHMWPE. UHMWPE‐g‐GO was used to compatibilize the immiscible monomer casting (MC) nylon/UHMWPE blends. With the addition of very low content of UHMWPE‐g‐GO, the compatibility of UHMWPE and the matrix (MC nylon) was remarkably improved without visible agglomerates, which was proved by photographs, scanning electron microscope, dynamic thermomechanical analysis, and contact angle measurement. Therefore, thermal stability, mechanical and tribological properties were obviously increased. A dramatic increment of 94.1% in the impact strength and a decrement of 39.4% in the coefficient friction were observed in the presence of UHMWPE‐g‐GO in the immiscible polymer blends. The approach used in this work was an efficient strategy for immiscible polymer blends with ultra‐high molecular weight. POLYM. ENG. SCI., 57:335–344, 2017. © 2016 Society of Plastics Engineers  相似文献   

9.
Poly(ethylene terephthalate) (PET)/SiO2 nanocomposites were prepared by in situ polymerization. The dispersion and crystallization behaviors of PET/SiO2 nanocomposites were characterized by means of transmission electron microscope (TEM), differential scanning calorimeter (DSC), and polarizing light microscope (PLM). TEM measurements show that SiO2 nanoparticles were well dispersed in the PET matrix at a size of 10–20 nm. The results of DSC and PLM, such as melt‐crystalline temperature, half‐time of crystallization and crystallization kinetic constant, suggest that SiO2 nanoparticles exhibited strong nucleating effects. It was found that SiO2 nanoparticles could effectively promote the nucleation and crystallization of PET, which may be due to reducing the specific surface free energy for nuclei formation during crystallization and consequently increase the crystallization rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 655–662, 2006  相似文献   

10.
In the present study, fumed silica (SiO2) nanoparticle reinforced poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) blend nanocomposite films were prepared via a simple solution‐blending technique. Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to elucidate the successful incorporation of SiO2 nanoparticles in the PVA/PVP blend matrix. A thermogravimetric analyzer was used to evaluate the thermal stability of the nanocomposites. The dielectric properties such as dielectric constant (?) and dielectric loss (tan δ) of the PVA/PVP/SiO2 nanocomposite films were evaluated in the broadband frequency range of 10?2 Hz to 20 MHz and for temperatures in the range 40–150 °C. The FTIR and UV–vis spectroscopy results implied the presence of hydrogen bonding interaction between SiO2 and the PVA/PVP blend matrix. The XRD and SEM results revealed that SiO2 nanoparticles were uniformly dispersed in the PVA/PVP blend matrix. The dielectric property analysis revealed that the dielectric constant values of the nanocomposites are higher than those of PVA/PVP blends. The maximum dielectric constant and the dielectric loss were 125 (10?2 Hz, 150 °C) and 1.1 (10?2 Hz, 70 °C), respectively, for PVA/PVP/SiO2 nanocomposites with 25 wt % SiO2 content. These results enable the preparation of dielectric nanocomposites using a facile solution‐casting method that exhibit the desirable dielectric performance for flexible organic electronics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44427.  相似文献   

11.
The polyamide 6 (PA6)/SiO2 nanocomposites were prepared by in situ polymerization and the rheological behaviors were investigated. The morphology of resultant materials was characterized by scanning electron microscopy (SEM) and the rheological behaviors were characterized by capillary rheometer. The results showed that the SiO2 particle size was around 50 nm and the particles dispersed evenly in PA6 matrix. The nanocomposites were pesudoplastic fluids and the apparent viscosities of nanocomposites increased initially and then decreased with the increase in nano-SiO2 content at the same temperature. The non-Newtonian indexes of nanocomposites were smaller than those of pure PA6. With the increase in nano-SiO2 content the apparent viscous activation energies of nanocomposites increased initially and then decreased. The rheological behaviors revealed that there were strong interactions between PA6 macromolecule chains and nano-SiO2 particles.  相似文献   

12.
ZrO2‐coated graphene oxide (GO)/SEBS(styrene‐ethylene‐butylene‐styrene)‐based nanocomposites were prepared for use as an electromagnetic interference (EMI) shielding material. Transmission electron microscopy (TEM) reveals almost every individual GO is fully and homogeneously covered with uniform ZrO2. X‐ray diffraction (XRD) patterns and Differential scanning calorimetry (DSC) revealed increased ordering of ‐(CH2‐CH2)n segments in the poly(ethylene‐co‐1‐butene) block of the SEBS matrix in the case of SEBS/ZrO2‐coated graphene oxide composites than in the SEBS/pristine graphene oxide nanocomposite. Thermogravimetric analysis (TGA) proved better oxidation resistance of SEBS/ZrO2‐coated GO nanocomposite compared to that of SEBS/pristine GO nanocomposite. The present nanocomposites exhibited excellent EMI shielding effectiveness (SE) over X‐band (8.2 GHz–12.4 GHz) with EMI SE of 37.9 dB. J. VINYL ADDIT. TECHNOL., 25:E130–E136, 2019. © 2018 Society of Plastics Engineers  相似文献   

13.
Polycarbonate nanocomposite containing silicon oxide nanoparticles average size of 5 nm at different weight ratio has been prepared by solution mixing method. The dispersion of nanoparticles in polymer matrix was studied by transmission electron microscopy (TEM). The optical and thermally stimulated behavior of nanocomposites were analyzed by energy dispersive X‐ray spectra (EDX), X‐ray diffraction pattern (XRD), UV–vis spectroscopy, differential scanning calorimetry (DSC), and thermally stimulated discharge current (TSDC). TEM images show the dispersion and size of the nanoparticles, however, EDX indicate the presence of SiO2 on the surface of the nanocomposite film. An XRD result reveals that the crystallinity increases with increase in concentration of SiO2 nanoparticles in polymer matrix. The direct and indirect optical energy band gaps decreased and number of carbon atom increased with concentration of SiO2 nanoparticles. We have observed that the increase of SiO2 nanoparticles in PC significantly reduces the refractive index. DSC and TSDC show that glass transition temperature increases according to SiO2 weight ratio. The TSDC of nanocomposites samples could be understand in terms of non‐Debye theory of charge relaxation and co‐tunneling mechanism of charge transport. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

14.
Poly(methyl methacrylate) grafted silica (SiO2‐g‐PMMA) was synthesized via in situ suspension polymerization. To achieve better uniform dispersion, hexadecyltrimethylammonium bromide (CTAB) was introduced into xylene to manipulate SiO2 aggregation. SiO2‐g‐PMMA or SiO2 was incorporated into PMMA matrix by in situ polymerization to prepare PMMA‐based nanocomposites. The effect of CTAB amount, in the range 0–35 wt %, on the modification was evaluated by DLS, TGA, and FTIR. Furthermore, morphology, optical, mechanical, and thermal properties of PMMA nanocomposites was characterized by SEM, UV–vis, DMA, and TGA. Owing to surface functionalization, SiO2‐g‐PMMA exhibited far more excellent compatibility and dispersion in matrix compared with SiO2. Surface hardness and thermal properties of nanocomposites were enhanced significantly under the premise in high transparency. It is expected that transparent nanocomposites with promising scratch‐resistance could have wide applications, such as airplane shielding window and daily furniture. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44612.  相似文献   

15.
A facile method to prepare superhydrophobic fluoropolymer/SiO2 nanocomposites coating on polyester (PET) fabrics was presented. The vinyl nanosilica (V? SiO2) hydrosols were prepared via one‐step water‐based sol‐gel reaction with vinyl trimethoxy silane as the precursors in the presence of the base catalyst and composite surfactant. Based on the V? SiO2 hydrosol, a fluorinated acrylic polymer/silica (FAP/SiO2) nanocomposite was prepared by emulsion polymerization. The FAP/SiO2 nanocomposites were coated onto the polyester fabrics by one‐step process to achieve superhydrophobic surfaces. The results showed that silica nanoparticles were successfully incorporated into the FAP/SiO2 nanocomposites, and a specific surface topography and a low surface free energy were simultaneously introduced onto PET fibers. The prepared PET fabric showed excellent superhydrophobicity with a water contact angle of 151.5° for a 5 μL water droplet and a water shedding angle of 12° for a 15 μL. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40340.  相似文献   

16.
Phase morphology, rheological, and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE)/PP/organo‐montmorillonite nanocomposites were investigated in this work. The results of TEM and XRD indicated that the organo‐montmorillonite PMM prepared with the complex intercalator [2‐methacryloyloxyethyldodecyldimethylammonium bromide/poly(ethylene glycol)] were exfoliated and dispersed into UHMWPE matrix, and the synergistic effect of the complex intercalator on the exfoliation and intercalation for montmorillonite occurred. Besides, the presence of PMM in UHMWPE matrix was found able to lead to a significant reduction of melt viscosity and enhancement in tensile strength and elongation at break of UHMWPE, except that izod‐notched impact strength was without much obvious change. The dispersed PMM particles exhibited a comparatively large two‐dimensional aspect ratio (Lclay/dclay = 35.5), which played an important role in determining the enhancement of mechanical properties of UHMWPE nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

17.
In this study, poly(vinyl chloride) (PVC) and silica (SiO2) microcomposites and nanocomposites were prepared by melt mixing in a Haake torque rheometer. The fusion and rheological behaviors of PVC/SiO2 composites were evaluated by means of torque data recorded during processing to investigate the influence of the SiO2 particle size on these behaviors. It was found that the fusion time and the fusion temperature decreased with the decreasing of SiO2 particle size, whereas the fusion torque increased with the decreasing of particle size. The PVC/Si‐25‐nm nanocomposite (PVC including the 25 nm of SiO2) showed the highest apparent viscosity among the PVC/SiO2 microcomposites and nanocomposites prepared in this study. Scanning electron microscopy results demonstrated that some aggregates, whose sizes about 60–90 nm, were formed when the 25 nm of SiO2 was used as filler. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers  相似文献   

18.
We address the immobilization of single-site catalyst on the graphite oxide (GO) surface using methylaluminoxane. Ethylene polymerization was performed using the immobilized catalyst and the nanocomposite of ultrahigh molecular weight polyethylene (UHMWPE)/GO with less entanglement density was obtained. It was observed that the drawability, mechanical and thermal properties of the produced polymer significantly are affected by the anchoring of polymer chains to the GO nanosheets. The orientation and location of crystalline lamellae and nanosheets were verified by microscopic techniques. Besides, X-ray analysis demonstrated the dispersion of GO within the UHMWPE phase and crystallinity of UHMWPE/GO nanocomposites enhanced during drawing process.  相似文献   

19.
Nylon 6/carboxylic acid‐functionalized silica nanoparticles (SiO2‐COOH) nanocomposites were prepared by in situ polymerization of caprolactam in the presence of SiO2‐COOH. The aim of this work was to study the effect of carboxylic silica on the properties of the nylon 6 through the interfacial interactions between the SiO2‐COOH nanoparticles and the nylon 6 matrix. For comparison, pure nylon 6, nylon 6/SiO2 (unmodified) and nylon 6/amino‐functionalized SiO2 (SiO2‐NH2) were also prepared via the same method. Fourier transform infrared spectrometer (FTIR) spectroscopy was used to evaluate the structure of SiO2‐COOH and nylon 6/SiO2‐COOH. The results from thermal gravimetric analysis (TGA) indicated that decomposition temperatures of nylon 6/SiO2‐COOH nanocomposites at the 5 wt % of the total weight loss were higher than the pure nylon 6. Differential scanning calorimeter (DSC) studies showed that the melting point (Tm) and degree of crystallinity (Xc) of nylon 6/SiO2‐COOH were lower than the pure nylon 6. Mechanical properties results of the nanocomposites showed that nylon 6 with incorporation of SiO2‐COOH had better mechanical properties than that of pure nylon 6, nylon 6/SiO2, and nylon 6/SiO2‐NH2. The morphology of SiO2, SiO2‐NH2, and SiO2‐COOH nanoparticles in nylon 6 matrix was observed using SEM measurements. The results revealed that the dispersion of SiO2‐COOH nanoparticles in nylon 6 matrix was better than SiO2 and SiO2‐NH2 nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

20.
Dynamically vulcanized Nylon 1010/ethylene‐vinyl acetate rubber (EVM)/SiO2 nanocomposites were prepared. Maleic anhydride grafted ethylene‐vinyl acetate copolymer (EVA‐g‐MA) and nano‐silica (SiO2) was used as a compatibilizer and a filler, and silane coupling agent (KH550, 3‐triethoxysilylpropylamine) was used to improve the dispersion of SiO2 in the nanocomposites. The nanocomposites were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), and rheology analysis and mechanical properties test. SEM and AFM images showed that the compatibility between Nylon 1010 and EVM was improved by adding the compatibilizer. An increase in SiO2 content and the addition of the compatibilizer led to an increase in the tensile strength of the nanocomposite. A nanocomposite based on Nylon 1010/EVM/DCP (30/70/0.8) with tensile strength of 16.3 MPa and elongation at break of 180% was obtained by the addition of 15 phr EVA‐g‐MA and 40 phr SiO2. The non‐isothermal crystallization processes of Nylon/EVM blend were investigated by DSC. It was observed that EVM rubber could act as heterogeneous nuclei for Nylon which was more effective in Nylon/EVM/DCP blend than in Nylon/EVM blend. POLYM. ENG. SCI., 55:581–588, 2015. © 2014 Society of Plastics Engineers  相似文献   

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