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1.
Two types of 2D nanofillers, α‐zirconium phosphate (α‐ZrP) and graphene oxide (GO), were synthesized and incorporated into poly(vinyl alcohol) (PVA) with 1 wt % loading level at various α‐ZrP:GO (Z:G = 5:1, 2:1, 1:1, 1:2, and 1:5) ratios. The resulting nanocomposites were tested for barrier properties by casting films from solution. The structure and morphology of α‐ZrP and GO were characterized by Fourier‐transform infrared spectroscopy, atomic force microscope, scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction, which demonstrated successful preparation of exfoliated α‐ZrP and GO. The physical characteristics of the nanocomposite films, including thermal, mechanical, and gas barrier properties were investigated. The results indicated that the tensile strength, Young's modulus, and elongation at break of the PVA nanocomposite films with Z:G hybrid nanofiller improved compared to neat PVA. The glass transition temperature, melting temperature, and crystallinity also increased. Consequently there appears to be a synergistic effect with these two types of nanofillers that formed a specific macro structure of a “wall.” This macrostructure resulted in excellent O2 gas barrier properties with the PVA/Z:G‐5:1 nanocomposite films having the best performance. The of the PVA/Z:G‐5:1 nanocomposite decreased from 1.835 × 10?16 to 0.587 × 10?16 cm3 cm cm?2 s?1 Pa?1 compared with neat PVA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46455.  相似文献   

2.
Graphene oxide/poly(ethylene glycol) (GO/PEG) composites that have biocompatibility and biodegradability properties have been prepared to improve the lubrication of artificial joints, but they would be rapidly degraded and absorbed by the human body if injected. To prolong the lubrication effect, GO/PEG lubricants were mixed into a chitosan (CS) sol, and then the GO/PEG/CS sol was added to the dimpled texture of a Co‐Cr‐Mo alloy and transformed into a gel to slowly release GO/PEG lubricants. The results of friction experiments showed that the average friction coefficient of the slow‐release solution is below 0.025, especially when under pressure, and the gel in the texture also has a good lubrication effect. Meanwhile, the FTIR and UV–vis of the slow‐release solution indicated that it is likely to contain GO, PEG, and CS, which are associated with each other via hydrogen bonds and may form a particular structure, leading to good slow‐release lubrication. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45818.  相似文献   

3.
As novel piezoelectric materials, carbon‐reinforced polymer composites exhibit excellent piezoelectric properties and flexibility. In this study, we used a styrene–butadiene–styrene triblock copolymer covalently grafted with graphene (SBS‐g‐RGO) to prepare SBS‐g‐RGO/styrene–butadiene–styrene (SBS) composites to enhance the organic solubility of graphene sheets and its dispersion in composites. Once exfoliated from natural graphite, graphene oxide was chemically modified with 1,6‐hexanediamine to functionalize with amino groups (GO–NH2), and this was followed by reduction with hydrazine [amine‐functionalized graphene oxide (RGO–NH2)]. SBS‐g‐RGO was finally obtained by the reaction of RGO–NH2 and maleic anhydride grafted SBS. After that, X‐ray diffraction, X‐ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and other methods were applied to characterize SBS‐g‐RGO. The results indicate that the SBS molecules were grafted onto the graphene sheets by covalent bonds, and SBS‐g‐RGO was dispersed well. In addition, the mechanical and electrical conductivity properties of the SBS‐g‐RGO/SBS composites showed significant improvements because of the excellent interfacial interactions and homogeneous dispersion of SBS‐g‐RGO in SBS. Moreover, the composites exhibited remarkable piezo resistivity under vertical compression and great repeatability after 10 compression cycles; thus, the composites have the potential to be applied in sensor production. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46568.  相似文献   

4.
Epoxy resin nanocomposites incorporated with 0.5, 1, 2, and 4 wt % pristine graphene and modified graphene oxide (GO) nanoflakes were produced and used to fabricate carbon fiber‐reinforced and glass fiber‐reinforced composite panels via vacuum‐assisted resin transfer molding process. Mechanical and thermal properties of the composite panels—called hierarchical graphene composites—were determined according to ASTM standards. It was observed that the studied properties were improved consistently by increasing the amount of nanoinclusions. Particularly, in the presence of 4 wt % GO in the resin, tensile modulus, compressive strength, and flexural modulus of carbon fiber (glass fiber) composites were improved 15% (21%), 34% (84%), and 40% (68%), respectively. Likewise, with inclusion of 4 wt % pristine graphene in the resin, tensile modulus, compressive strength, and flexural modulus of carbon fiber (glass fiber) composites were improved 11% (7%), 30% (77%), and 34% (58%), respectively. Also, thermal conductivity of the carbon fiber (glass fiber) composites with 4% GO inclusion was improved 52% (89%). Similarly, thermal conductivity of the carbon fiber (glass fiber) composites with 4% pristine graphene inclusion was improved 45% (80%). The reported results indicate that both pristine graphene and modified GO nanoflakes are excellent options to enhance the mechanical and thermal properties of fiber‐reinforced polymeric composites and to make them viable replacement materials for metallic parts in different industries, such as wind energy, aerospace, marine, and automotive. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40826.  相似文献   

5.
Cellulose–graphene oxide (GO) aerogel composites were successfully prepared from cellulose and GO dispersed in N‐methyl morpholine‐N‐oxide monohydrate, a nontoxic and environmentally friendly solvent, after a freeze‐drying process. Because of the strong interactions between the numerous oxygen‐containing groups located on the surface of GO and the functional groups of the cellulose molecules, the GO monolayers were well dispersed in the three‐dimensional porous structure of the cellulose aerogels. With the addition of 10 wt % GO, the swelling ratios and water contents of the composite cellulose–GO aerogels increased from 468 to 706% and from 82.4% to 87.6%, respectively. The corresponding maximum decomposition temperatures also increased from 335 to 353 °C with increasing GO content from 0 to 10%; this indicated that the thermal stability of the cellulose–GO aerogels was enhanced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46152.  相似文献   

6.
氧化石墨烯改性热固性酚醛树脂的热性能研究   总被引:1,自引:0,他引:1  
采用原位聚合法和溶液共混法制备氧化石墨烯(GO)改性热固性酚醛树脂,分析GO的加入量和加入方式对酚醛树脂热性能的影响。在原位聚合法制备的改性树脂中,GO的引入使酚醛树脂的Tg略有下降,随着GO加入量的增加,树脂的残碳率和第一阶段的热分解温度先升高后降低;相比于原位聚合法,溶液共混法制备的改性树脂中,树脂的耐热性更佳,GO的分散尺度更小。  相似文献   

7.
To improve the thermal and mechanical properties and further to expand its applications of epoxy in electronic packaging, reduced graphene oxide/epoxy composites have been successfully prepared, in which dopamine (DA) was used as reducing agent and modifier for graphene oxide (GO) to avoid the environmentally harmful reducing agents and address the problem of aggregation of graphene in composites. Further studies revealed that DA could effectively eliminate the labile oxygen functionality of GO and generate polydopamine functionalized graphene oxide (PDA‐GO) because DA would be oxidated and undergo the rearrangement and intermolecular cross‐linking reaction to produce polydopamine (PDA), which would improve the interfacial adhesion between GO and epoxy, and further be beneficial for the homogenous dispersion of GO in epoxy matrix. The effect of PDA‐GO on the thermal and mechanical properties of PDA‐GO/epoxy composites was also investigated, and the incorporation of PDA‐GO could increase the thermal conductivity, storage modulus, glass transition (Tg), and dielectric constant of epoxy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39754.  相似文献   

8.
Carbon–phenolic (CF–PR) composites with 0.1 wt % graphene oxide (GO) and acidified graphitic carbon nitride (ag‐C3N4) were synthesized and characterized to understand their thermal properties. The thermal conductivity, coefficient thermal expansion, dynamic mechanical analysis, and scanning electron microscopy were used in our experimental efforts. The results demonstrate that the ag‐C3N4‐filled composite had 17.17% and 54% reductions in the thermal conductivity and coefficient thermal expansion, respectively, when compared with the neat composite, although the GO‐filled showed a 8.54% decrease and a 30% increase, respectively. Furthermore, reactive molecular dynamics simulation was used to investigate the mechanisms at the atomistic level when the composites are subjected to thermal behavior. The simulated results show that the influence of GO and ag‐C3N4 on the thermal conductivities of the composites was different. Lowly loaded GO favored the more interfacial thermal resistance. However, the stronger electronegativity in ag‐C3N4 favored the formation of a vacuum zone in the matrix; this contributed to increasing the interfacial boundaries and defect scattering. The simulation results are expected to be of great help to serve as a guide for further experiments concerning the thermal properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46242.  相似文献   

9.
In an attempt to enhance the mechanical properties of epoxy/graphene‐based composites, the interface was engineered through the functionalization of graphene oxide (GO) sheets with p‐phenylenediamine; this resulted in p‐phenylenediamine functionalized graphene oxide (GO–pPDA). The morphology and chemical structure of the GO–pPDA sheets were studied by spectroscopic methods, thermal analysis, X‐ray diffraction, and transmission electron microscopy. The characterization results show the successful covalent functionalization of GO sheets through the formation of amide bonds. In addition, p‐phenylenediamine were polymerized on graphene sheets to form crystalline nanospheres; this resulted in a GO/poly(p‐phenylenediamine) hybrid. The mechanical properties of the epoxy/GO–pPDA composite were assessed. Although the Young's modulus showed improvement, more significant improvements were observed in the strength, fracture strain, and plane‐strain fracture toughness. These improvements were attributed to the unique microstructure and strong interface between GO–pPDA and the epoxy matrix. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43821.  相似文献   

10.
A new kind of flame retardant (ZS) with layered α‐zirconium phosphate disks (α‐ZrP) as the core and inorganic flame retardant (gel‐silica, GS) to shield solid acid sites on the surface of α‐ZrP as the shell, was synthesized via a facile method. The incorporation effects of ZS with silicone resin on the thermal properties and flame retardance of PC composites were investigated. The presence of ZS could improve the thermal stability of PC matrix. With the addition of ZS contents increased to 3 wt %, the limiting oxygen index (LOI) of the composite was 32.3% and the vertical burning (UL‐94) test reached a V‐0 rating. However, with more contents of ZS, the LOI value decreased, and without the GS layer, the LOI value was decreased significantly as well. The synergism between the α‐ZrP core and gel‐silica shell, also with the silicone resin were found. Based on these results, the flame‐retardant mechanism was proposed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44829.  相似文献   

11.
Development of high‐performance thermosetting resins by adding environmentally friendly flame retardant to heat‐resistant resins without deteriorating their outstanding thermal stability is an important research direction. Here, a unique hybrid (GHNT) consisting of graphene oxide (GO) and halloysite nanotubes (HNT) was synthesized, and then a series of composites based on cyanate ester (CE) resin were fabricated. The effects of GHNT on the heat resistance, flame retardancy, and smoke suppression of GHNT/CE composites were intensively investigated. The GHNT/CE composite with 5.0 wt % GHNT not only has about 15.1 °C higher initial degradation temperature, but also shows 54.6% or 37.9% lower peak heat release rate or maximum smoke density than CE resin. These results clearly demonstrate that GHNT is not the simple combination of GO and HNT; instead, it obviously shows positive synergistic effects in simultaneously improving the flame retardancy and thermal resistance of CE resin. The improved flame retardancy could be attributed to condensed‐phase mechanisms, including increasing char yield, building a dense char layer, and free radical scavenging. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46587.  相似文献   

12.
Dodecyl amine (DA) functionalized graphene oxide(DA‐GO) and dodecyl amine functionalized reduced graphene oxide (DA‐RGO) were produced by using amidation reaction and chemical reduction, then two kinds of well dispersed DA‐GO/high‐density polyethylene (HDPE) and DA‐RGO/HDPE nanocomposites were prepared by solution mixing method and hot‐pressing process. Thermogravimetric, X‐ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, X‐ray diffractions, and Raman spectroscopy analyses showed that DA was successfully grafted onto the graphene oxide surface by uncleophilic substitution and the amidation reaction, which increased the intragallery spacing of graphite oxide, resulting in the uniform dispersion of DA‐GO and DA‐RGO in the nonpolar xylene solvent. Morphological analysis of nanocomposites showed that both DA‐GO and DA‐RGO were homogeneously dispersed in HDPE matrix and formed strong interfacial interaction. Although the crystallinity, dynamic mechanical, gas barrier, and thermal stability properties of HDPE were significantly improved by addition of small amount of DA‐GO or DA‐RGO, the performance comparison of DA‐GO/HDPE and DA‐RGO/HDPE nanocomposites indicated that the reduction of DA‐GO was not necessary because the interfacial adhesion and aspect ratio of graphene sheets had hardly changed after reduction, which resulting in almost the same properties between DA‐GO/HDPE and DA‐RGO/HDPE nanocomposites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39803.  相似文献   

13.
The graphene oxide (GO) was prepared by sonication‐induced exfoliation from graphite oxide, which was produced by oxidation from graphite flakes with a modified Hummer's method. The GO was then treated by hydrazine to obtain reduced graphene oxide (rGO). On the basis of the characterization results, the GO was successfully reduced to rGO. Acrylonitrile–butadiene rubber (NBR)–GO and NBR–rGO composites were prepared via a solution‐mixing method, and their various physical properties were investigated. The NBR–rGO nanocomposite demonstrated a higher curing efficiency and a change in torque compared to the gum and NBR–GO compounds. This agreed well with the crosslinking density measured by swelling. The results manifested in the high hardness (Shore A) and high tensile modulus of the NBR–rGO compounds. For instance, the tensile modulus at a 0.1‐phr rGO loading greatly increased above 83, 114, and 116% at strain levels of 50, 100, and 200%, respectively, compared to the 0.1‐phr GO loaded sample. The observed enhancement was highly attributed to a homogeneous dispersion of rGO within the NBR matrix; this was confirmed by scanning electron microscopy and transmission electron microscopy analysis. However, in view of the high ultimate tensile strength, the NBR–GO compounds exhibited an advantage; this was presumably due to strong hydrogen bonding or polar–polar interactions between the NBR and GO sheets. This interfacial interaction between GO and NBR was supported by the marginal increase in the glass‐transition temperatures of the NBR compounds containing fillers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42457.  相似文献   

14.
We successfully prepared a graphene-modified carbon fiber (CF) sizing agent with good dispersity and stability by dispersing reduced graphene oxide (RGO) into an emulsion-type sizing agent. RGO was obtained by the reduction of graphene oxide (GO) with the help of gallic acid. The influence of the graphene-modified sizing agent on the interfacial properties of the CF–epoxy resin composites was investigated with microbond testing and the three-point bending method. The results show that optimized interfacial properties were achieved when the size of the modified graphene was less than 1 μm, the content of RGO was 20 ppm, and the pH value of the sizing agent was 10.5. The interfacial shear strength of the composites reached 92.3 MPa, which was 29.6% higher than that of the composites with unmodified CFs. Compared with commercial-CF-fabric-reinforced composites, the interlaminar shear strength of the composites treated with the RGO-modified sizing agent increased by 21.5%. Both the interfacial and interlaminar failure morphologies of the composites were examined with scanning electron microscopy (SEM). The results show that a large amount of residual resin adhered to the surfaces of the CFs treated with the RGO-modified sizing agent; this indicated good interfacial properties between the CFs and the resin matrix. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47122.  相似文献   

15.
Currently, there is great interest in graphene‐based devices and applications because graphene has unique electronic and material properties, which can lead to enhanced material performance. Graphene may be used in a wide variety of potential applications from next‐generation transistors to lightweight and high‐strength polymeric composite materials. Graphene, which has atomic thickness and two‐dimensional sizes in the tens of micrometer range or larger, has also been considered a promising nanomaterial in gas‐ or liquid‐barrier applications because perfect graphene sheets do not allow diffusion of small gases or liquids through its plane. Recent molecular simulations and experiments have demonstrated that graphene and its derivatives can be used for barrier applications. In general, graphene and its derivatives can be applied via two major routes for barrier polymer applications. One is the transfer or coating of few‐layered, ultrathin graphene and its derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), on polymeric substrates. The other is the incorporation of fully exfoliated GO or rGO nanosheets into the polymeric matrix. In this article, we review the state‐of‐the‐art research on the use of graphene, GO, and rGO for barrier applications, including few‐layered graphene or its derivatives in coated polymeric films and polymer nanocomposites consisting of chemically exfoliated GO and rGO nanosheets, and their gas‐barrier properties. As compared to other nanomaterials being used for barrier applications, the advantages and current limitations are discussed to highlight challenging issues for future research and the potential applications of graphene/polymer, GO/polymer, and rGO/polymer composites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39628.  相似文献   

16.
In this article, samples of phenolic resin reinforced with graphene oxide were prepared. Mechanical properties of the composite were tested. Dynamic mechanical analysis, Fourier transform infrared spectroscopy, Differential scanning calorimetry, and thermogravimetric analysis were employed to study the mechanical properties in varied temperatures to infer the influence of graphene oxide on thermal performance of phenolic resin. The results show that the addition of graphene oxide resulted in a significant improvement in the elastic modulus of phenolic resin; Young's modulus, and tensile strength increase along with the graphene oxide content. Esterification reaction happened between alcohol  OH groups on resole and carbonyl (sbond]COOH) groups on graphene oxide. Addition of graphene oxide improved residue rate of phenolic resin by 5.8%, whereas the temperature distribution of phenolic pyrolysis stay unchanged. The glass transition temperature of phenolic resin has been improved by 30°C. POLYM. COMPOS. 34:1245–1249, 2013. © 2013 Society of Plastics Engineers  相似文献   

17.
《Polymer Composites》2017,38(5):852-862
Conjugated polymer‐layered filler nanocomposites have received extensive interest as multifunctional materials in various futuristic applications. In this study, the effect of graphene oxide (GO) particle size on the synthesis, optical, and electrochemical properties of in situ prepared graphene oxide (GO)‐poly(3‐hexylthiophene) (P3HT) nanocomposites have been studied. The intercalation of GO with P3HT is inferred from shifting and broadening of the characteristic D‐ and G‐bands of GO in Raman spectra and also the vibrational frequencies in FTIR. This interaction is further confirmed from increase of the optical band gap and the ellipsometry data. The UV–visible absorption maximum (λ max) of P3HT decreases from 438 to 418 nm in the nanocomposite owing to ionic interactions between GO and the polymer causing a decrease of the polymer conjugation length. Compared to the homopolymer, the emission maximum of the composite is broadened and enhanced in intensity with 10 wt% GO but emission quenching is observed with GO nanoparticles. The evidence of polymer intercalation was also deduced from the determination of the basal spacing and unit cell dimensions of GO, using X‐ray diffraction data. Morphological studies using field emission scanning electron microscopy suggest that the crystalline rod‐like structures observed in the homopolymer have changed to more amorphous, flaky, and porous structures. The cyclic voltammetry studies show an increase in current with increasing GO content in the porous nanocomposites. POLYM. COMPOS., 38:852–862, 2017. © 2015 Society of Plastics Engineers  相似文献   

18.
In this study, the gallic acid‐based epoxy resin (GA‐ER) and alkali‐catalysed biphenyl‐4,4′‐diol formaldehyde resin (BPFR) are synthesized. Glass fibre‐reinforced GA‐ER/BPFR composites are prepared. Graphene oxide (GO) is used to improve the mechanical and thermal properties of GA‐ER/BPFR composites. Dynamic mechanical properties and thermal, mechanical, and electrical properties of the composites with different GO content are characterized. The results demonstrate that GO can enhance the mechanical and thermal properties of the composites. The glass transition temperature, Tg, of the BPFR/GA‐ER/GO composites is 20.7°C higher than the pure resin system, and the 5% weight loss temperature, Td5, is enhanced approximately 56.6°C. When the BPFR: GA‐ER mass ratio is at 4 : 6 and GO content is 1.0–1.2 wt %, the tensile and impact strengths of composites are 60.97 MPa and 32.08 kJ/m2 higher than the pure resin composites, respectively. BPFR/GA‐ER composites have better mechanical properties, and can replace common BPA epoxy resins in the fabrication of composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42637.  相似文献   

19.
In this work, to investigate the addition effect of 2D α‐zirconium phosphate (α‐ZrP) nanosheets on the properties of polyimide (PI), a series of PI/ZrP composites are synthesized by in situ polymerization. The thermal, mechanical, and tribological properties of composites strongly depend on the dispersity and distribution of α‐ZrP nanosheets in the PI matrix. The dispersed α‐ZrP can make rich interfacial interactions with PI matrix, which facilitates the transfer of external stress, heat, antiwear ability, etc., from the PI matrix to the surface of the α‐ZrP nanosheets, leading to the obvious enhancements of the thermal, mechanical, and tribological properties of the PI/ZrP composites. Specially, compared with pure PI, the tensile strength and elongation at break of the optimum sample of PI‐0.6 are increased by 13.7% and 35.7%, while its wear volume is reduced by 85%. This work provides a new paradigm for using other layered 2D nanosheets to prepare high‐performance PI‐based composite materials.  相似文献   

20.
We report an in situ thermal reduction of graphene oxide (GO) in a styrene–ethylene/butylene–styrene (SEBS) triblock copolymer matrix during a melt‐blending process. A relatively high degree of reduction was achieved by melt‐blending premixed GO/SEBS nanocomposites in a Haake mixer for 25 min at 225 °C. Infrared spectral results revealed the successful thermal reduction of, and the strong adsorption of SEBS on, the graphene sheets. The glass transition temperature of polystyrene (PS) segments in SEBS was enhanced by the incorporation of thermally reduced graphene oxide (TRGO). The resultant TRGO/SEBS nanocomposites were used as a masterbatch to improve the mechanical properties of PS. Both the elongation at break and the flexural strength of PS/SEBS blends were enhanced with the addition of the TRGO. Our demonstration of the in situ thermal reduction of GO via melt blending is a simple, efficient strategy for preparing nanocomposites with well‐dispersed TRGO in the polymer matrix, which could be an important route for large‐scale fabrication of high‐performance graphene/polymer nanocomposites. © 2013 Society of Chemical Industry  相似文献   

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