共查询到20条相似文献,搜索用时 31 毫秒
1.
Along with carbon nanotubes (CNT) morphology, impurity, and functionalization, polymer curing cycle is another important factor in determining the mechanical properties of the CNT/polymer composite samples. This work investigates the effect of two different curing cycles on mechanical and thermo-mechanical properties of the nanotube in the composite in order to optimize the curing condition in term of time and temperature. Nanocomposite samples were prepared by mixing multi-wall carbon nanotubes with epoxy resin using sonication method. The mechanical and viscoelastic properties of the resulting composite samples were evaluated by performing tensile and dynamic mechanical thermal analyses (DMTA) test. The results indicate that the mechanical and viscoelastic properties of pure epoxy and composite samples have been affected by the condition curing process. Concerning viscoelastic modeling, the COLE–COLE diagram has been plotted by the result of DMTA tests. These results show a good agreement between the Perez model and the viscoelastic behavior of the composite. 相似文献
2.
Multi-walled carbon nanotubes (MWNTs) were sonicated in the dimethylformamide solution of poly(vinylidene fluoride) (PVDF). The PVDF-covered MWNTs were then melt-blended with poly(methyl methacrylate) (PMMA). The dynamic mechanical behavior of various composites was studied. The presence of a small amount of PVDF leads to a significant improvement in the storage moduli of the MWNT/PMMA composites at low temperatures. The storage modulus of a PVDF/MWNT/PMMA composite containing 0.5 wt.% PVDF is almost twice as that of a MWNT/PMMA composite at 50°C. However, a further increase in the PVDF content leads to a reduction of the storage modulus. The beneficial effect of PVDF diminishes at higher temperatures. 相似文献
3.
Jiao-Ping YangZhen-Kun Chen Qing-Ping Feng Yin-Hu DengYu Liu Qing-Qing NiShao-Yun Fu 《Composites Part B》2012,43(1):22-26
Cryogenic mechanical properties are important parameters for epoxy resins used in cryogenic engineering areas. In this study, multi-walled carbon nanotubes (MWCNTs) were employed to reinforce diglycidyl ether of bisphenol F (DGBEF)/diethyl toluene diamine (DETD) epoxy system modified by poly(ethersulfone) (PES) for enhancing the cryogenic mechanical properties. The epoxy system was properly modified by PES in our previous work and the optimized formulation of the epoxy system was reinforced by MWCNTs in the present work. The results show that the tensile strength and Young’s modulus at 77 K were enhanced by 57.9% and 10.1%, respectively. The reported decrease in the previous work of the Young’s modulus of the modified epoxy system due to the introduction of flexible PES is offset by the increase of the modulus due to the introduction of MWCNTs. Meanwhile, the fracture toughness (KIC) at 77 K was improved by about 13.5% compared to that of the PES modified epoxy matrix when the 0.5 wt.% MWCNT content was introduced. These interesting results imply that the simultaneous usage of PES and MWCNTs in a brittle epoxy resin is a promising approach for efficiently modifying and reinforcing epoxy resins for cryogenic engineering applications. 相似文献
4.
Arash Montazeri Jafar Javadpour Alireza Khavandi Abbas Tcharkhtchi Ali Mohajeri 《Materials & Design》2010
Untreated and acid-treated multi-walled carbon nanotubes (MWNT) were used to fabricate MWNT/epoxy composite samples by sonication technique. The effect of MWNT addition and their surface modification on the mechanical properties were investigated. Modified Halpin–Tasi equation was used to evaluate the Young’s modulus and tensile strength of the MWNT/epoxy composite samples by the incorporation of an orientation as well as an exponential shape factor in the equation. There was a good correlation between the experimentally obtained Young’s modulus and tensile strength values and the modified Halpin–Tsai theory. The fracture surfaces of MWNT/epoxy composite samples were analyzed by scanning electron microscope. 相似文献
5.
Carbon nanotube (CNT)/cellulose composite materials were fabricated in a paper making process optimized for a CNT network to form on the cellulose fibers. The measured electric conductivity was from 0.05 to 671 S/m for 0.5–16.7 wt.% CNT content, higher than that for other polymer composites. The real permittivities were the highest in the microwave region. The unique CNT network structure is thought to be the reason for these high conductivity and permittivity values. Compared to other carbon materials, our carbon CNT/cellulose composite material had improved parameters without decreased mechanical strength. The near-field electromagnetic shielding effectiveness (EMI SE) measured by a microstrip line method depended on the sheet conductivity and qualitatively matched the results of electromagnetic field simulations using a finite-difference time-domain simulator. A high near-field EMI SE of 50-dB was achieved in the 5–10 GHz frequency region with 4.8 wt.% composite paper. The far-field EMI SE was measured by a free space method. Fairly good agreement was obtained between the measured and calculated results. Approximately 10 wt.% CNT is required to achieve composite paper with 20-dB far-field EMI SE. 相似文献
6.
Toshio Ogasawara Sook-Young MoonYoku Inoue Yoshinobu Shimamura 《Composites Science and Technology》2011,71(16):1826-1833
This study examined the mechanical properties of aligned multi-walled carbon nanotube (CNT)/epoxy composites processed using a hot-melt prepreg method. Vertically aligned ultra-long CNT arrays (forest) were synthesized using chemical vapor deposition, and were converted to horizontally aligned CNT sheets by pulling them out. An aligned CNT/epoxy prepreg was fabricated using hot-melting with B-stage cured epoxy resin film. The resin content in prepreg was well controlled. The prepreg sheets showed good drapability and tackiness. Composite film specimens of 24-33 μm thickness were produced, and tensile tests were conducted to evaluate the mechanical properties. The resultant composites exhibit higher Young’s modulus and tensile strength than those of composites produced using conventional CNT/epoxy mixing methods. For example, the maximum elastic modulus and ultimate tensile strength (UTS) of a CNT (21.4 vol.%)/epoxy composite were 50.6 GPa and 183 MPa. These values were, respectively, 19 and 2.9 times those of the epoxy resin. 相似文献
7.
Carbon fiber reinforced epoxy composite laminates, with strategically incorporated fluorine functionalized carbon nanotubes (f-CNTs) at 0.2, 0.3 and 0.5 weight percent (wt.%), are studied for improvements in tensile strength and stiffness and durability under both tension–tension (R = +0.1) and tension–compression (R = −0.1) cyclic loadings, and then compared to the neat (0.0 wt.% CNTs) composite laminate material. To develop the nanocomposite laminates, a spraying technology was used to deposit nanotubes on both sides of each four-harness satin weave carbon fiber fabric piece for the 12 ply laminate lay up. For these experimental studies the carbon fiber reinforced epoxy laminates were fabricated using a heated vacuum assisted resin transfer molding (H-VARTM®) method followed by a 2 soak curing cycle. The f-CNTs toughened the epoxy resin-fiber interfaces to mitigate the evolution of fiber/fabric-matrix interfacial cracking and delamination under both static and cyclic loadings. As a consequence, significant improvements in the mechanical properties of tensile strength, stiffness and resistance to failure due to cyclic loadings resulted for this carbon fiber reinforced epoxy composite laminate. 相似文献
8.
Effect of inclusions size and weight fraction on flexural strength and failure mode of composite containing SC-15 epoxy resin and TiO2 particles has been studied in this investigation. The sizes of particles varied from macro (0.02 mm) to nano (5 nm) scale, and these particles were infused into the part-A of SC-15 through sonic cavitations and then mixed with part-B of SC-15 by using a high speed mechanical agitator. Three-point bending tests were performed on unfilled, 0.5 wt.%, 1.0 wt.% and 1.5 wt.% particles filled SC-15 epoxy to identify the loading effect on mechanical properties of the composites. Results show that 1.0 wt.% nanoparticles reinforced epoxy exhibit the highest mechanical performance. Higher than 1.0%, strength of composite decreased because of poor dispersion. Experimental results also shown that micro-sized particles have little effect on strength of epoxy at such low loading, and strength of composite increased as the size of particles decreased to nano scale. However, degradation in strength was found in 5 nm TiO2/epoxy system due to agglomeration. 相似文献
9.
Role of matrix modification on interlaminar shear strength of glass fibre/epoxy composites 总被引:1,自引:0,他引:1
Yu Liu Jiao-Ping YangHong-Mei Xiao Cheng-Bing QuQing-Ping Feng Shao-Yun Fu Yasuhide Shindo 《Composites Part B》2012,43(1):95-98
Interlaminar shear properties of fibre reinforced polymer composites are important in many structural applications. Matrix modification is an effective way to improve the composite interlaminar shear properties. In this paper, diglycidyl ether of bisphenol-F/diethyl toluene diamine system is used as the starting epoxy matrix. Multi-walled carbon nanotubes (MWCNTs) and reactive aliphatic diluent named n-butyl glycidyl ether (BGE) are employed to modify the epoxy matrix. Unmodified and modified epoxy resins are used for fabricating glass fibre reinforced composites by a hot-press process. The interlaminar shear strength (ILSS) of the glass fibre reinforced composites is investigated and the results indicate that introduction of MWCNT and BGE obviously enhances the ILSS. In particular, the simultaneous addition of 0.5 wt.% MWCNTs and 10 phr BGE leads to the 25.4% increase in the ILSS for the glass fibre reinforced composite. The fracture surfaces of the fibre reinforced composites are examined by scanning electron microscopy and the micrographs are employed to explain the ILSS results. 相似文献
10.
Characterization of epoxy functionalized graphite nanoparticles and the physical properties of epoxy matrix nanocomposites 总被引:1,自引:0,他引:1
Sandi G. Miller Jonathan L. Bauer Michael J. Maryanski Paula J. Heimann Jeremy P. Barlow Jan-Michael Gosau Ronald E. Allred 《Composites Science and Technology》2010
This work presents a novel approach to the functionalization of graphite nanoparticles. The technique provides a mechanism for covalent bonding between the filler and matrix, with minimal disruption to the sp2 hybridization of the pristine graphene sheet. Functionalization proceeded by covalently bonding an epoxy monomer to the surface of expanded graphite, via a coupling agent, such that the epoxy concentration was measured as approximately 4 wt.%. The impact of dispersing this material into an epoxy resin was evaluated with respect to the mechanical properties and electrical conductivity of the graphite–epoxy nanocomposite. At a loading as low as 0.5 wt.%, the electrical conductivity was increased by five orders of magnitude relative to the base resin. The material yield strength was increased by 30% and Young’s modulus by 50%. These results were realized without compromise to the resin toughness. 相似文献
11.
Yuanqing LiTing Yu Tzesian PuiPeng Chen Lianxi ZhengKin Liao 《Composites Science and Technology》2011,71(14):1665-1670
A surface-draw method to fabricate recyclable carbon nanotube/polyvinyl butyral (CNT/PVB) composite fibers is reported. This method is effective for both single-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube. The CNT mass content of CNT/PVB composite fibers can vary from 0 to 80 wt.%, which is higher than most CNT/polymer composites reported to date. The diameter of the composite fibers can be controlled in the range of 10-100 μm, with essentially unlimited draw length. The composite fibers with 7.4 wt.% SWCNTs showed optimal tensile properties. Compared with pure PVB fibers, the tensile strength, failure strain, and elastic modulus of the composite fiber have improved about 127%, 27%, and 73%, respectively. In addition, SWCNT/PVB composites with 66.7 wt.% SWCNTs have the highest conductivity of 42.9 S m−1. More importantly, the major benefit is the “greenness” of the method, which involves environment friendly ethanol-water solvent with no functionalization of the nanotube required, and only simple apparatus are needed. The CNT/PVB composite fibers obtained can be dissolved in ethanol solution and reformed with the surface draw method without any additional treatment; and the material properties after recycle is comparable to those fabricated in the first round. 相似文献
12.
This study examined the effects of multi-walled carbon nanotube (CNT) dispersion on stress-strain behaviors of poly-ether-ether-ketone (PEEK) at room temperature. Tensile test specimens containing 9 wt.% and 15 wt.% of CNT were fabricated using injection molding. Results of focused ion beam (FIB) observations show that many CNTs in the CNT/PEEK composite are aligned longitudinally. Although the PEEK stress-strain behavior is almost linear up to 1.5% strain, the stress-strain curves of CNT/PEEK composites exhibit considerable nonlinear and hysteretic behaviors from extremely low strain (<0.1%) under both tensile and compressive loading. The experimental results suggest that the viscoelastic deformation effects on nonlinear and hysteresis behaviors are not strong below 1.5% strain. Presumably, the slippage at the CNT-PEEK interface occurs with increasing applied stress because of poor interfacial load-transfer capability. 相似文献
13.
Multi-walled carbon nanotube (MWNT)-reinforced carbon fiber/silicon carbide (Cf/SiC) composites were prepared using a polymer infiltration and pyrolysis (PIP) process. The MWNTs used in this study were modified using a chemical treatment. The MWNTs were found to be well dispersed in the matrix after ultrasonic dispersion, and the mechanical properties of the Cf/SiC composite were significantly improved by the addition of MWNTs. The addition of 1.5 wt.% of MWNTs to the Cf/SiC composite led to a 29.7% increase in the flexural strength, and a 27.9% increase in the fracture toughness. 相似文献
14.
Chang-Rong YuDa-Ming Wu Ying LiuHui Qiao Zhong-Zhen Yu Aravind Dasari Xu-Sheng DuYiu-Wing Mai 《Composites Science and Technology》2011,71(15):1706-1712
Functional polypropylene (PP) nanocomposites were prepared by melt compounding with multiwalled carbon nanotubes (MWNT) as the electrically conductive component and barium titanate (BT) spherical nanoparticles as the ferroelectric component. To make PP electrically conductive, more than 3 wt.% MWNT is required. Surface modification of either MWNT or BT with titanate coupling agent further improves the electrical conductivity of the PP/MWNT/BT ternary nanocomposites. Interestingly, by modifying both MWNT and BT, 2 wt.% MWNT are sufficient to make the ternary nanocomposite electrically conductive. In addition, the incorporation of MWNT greatly increases the dielectric permittivity of PP/BT nanocomposites. However, to retain a low dielectric loss, the MWNT loading should be slightly less than the percolation threshold of the nanocomposites. The improved electrical conductivity and dielectric properties make the ternary nanocomposites attractive in practical applications. 相似文献
15.
Kah Ling Low Soon Huat Tan Sharif Hussein Sharif Zein David S. McPhail Aldo R. Boccaccini 《Materials & Design》2011
Response surface methodology (RSM) coupled with the central composite design (CCD) was used to optimize the mechanical properties of calcium phosphate cement/multi-walled carbon nanotubes/bovine serum albumin (CPC/MWCNTs/BSA) composites. In this study, CPC composites were reinforced by multi-walled carbon nanotubes (MWCNTs) and bovine serum albumin (BSA) in order to induce high mechanical properties in the CPC/MWCNTs/BSA system. The effect of various process parameters on the compressive strength of CPC/MWCNTs/BSA composites was studied using design of experiments (DOE). The process parameters studied were: wt.% of MWCNTs (0.2–0.5 wt.%), wt.% of BSA (5–15 wt.%) and type of MWCNTs (e.g. as-pristine MWCNT (MWCNT-AP), hydroxyl group functionalized MWCNT (MWCNT-OH) and carboxyl group functionalized MWCNT (MWCNT-COOH)). Based on the CCD, a quadratic model was obtained to correlate the process parameters to the compressive strength of CPC/MWCNTs/BSA composites. From the analysis of variance (ANOVA), the most significant factor affected on the experimental design response was identified. The predicted compressive strength after process optimization was found to agree well with the experimental value. The results revealed that at 0.5 wt.% of MWCNT-OH and 15 wt.% of BSA, the highest compressive strength of 14 MPa was obtained. 相似文献
16.
The interest in carbon nanotubes (CNTs) as reinforcements for aluminium (Al) has been growing considerably. Efforts have been largely focused on investigating their contribution to the enhancement of the mechanical performance of the composites. The uniform dispersion of CNTs in the Al matrix has been identified as being critical to the pursuit of enhanced properties. Ball milling as a mechanical dispersion technique has proved its potential. In this work, we use ball milling to disperse up to 5 wt.% CNT in an Al matrix. The effect of CNT content on the mechanical properties of the composites was investigated. Cold compaction and hot extrusion were used to consolidate the ball-milled Al–CNT mixtures. Enhancements of up to 50% in tensile strength and 23% in stiffness compared to pure aluminium were observed. Some carbide formation was observed in the composite containing 5 wt.% CNT. In spite of the observed overall reinforcing effect, the large aspect ratio CNTs used in the present study were difficult to disperse at CNT wt.% greater than 2, and thus the expected improvements in mechanical properties with increase in CNT weight content were not fully realized. 相似文献
17.
This investigation concerns about study the effect of natural fiber on high performance composite. Effect of addition microfibrillated cellulose (MFC) as natural fiber to plain woven carbon fiber reinforced plastic (CF) reinforced epoxy on mechanical and thermal properties has been investigated. CF/epoxy composites with addition 0.5, 1 and 2 wt.% of MFC were characterized by different techniques, namely tensile, DMA, fracture toughness (mode I) test and SEM. The results reveal that at 2 wt.% of MFC, initiation and propagation interlaminar fracture toughness in mode I improved significantly by 80% and 44% respectively. Although there is slight tendency to increase tensile strength and Young’s modulus with addition MFC up to 2%, it is still not significant with those low contents of MFC. With addition 2 wt.% MFC, the glass transition temperature increased by about 12 °C compared to neat CF/epoxy composite indicating better heat resistance with addition of MFC. 相似文献
18.
The porous WO3 (pore size 2–5 nm) nanoparticles were synthesized using a high intensity ultrasound irradiation of commercially available WO3 nanoparticles (80 nm) in ethanol. The high resolution transmission electron microscopic (HRTEM) and X-ray studies indicated that the 2–5 nm uniform pores have been created in commercially available WO3 nanoparticles without much changing the initial WO3 nanoparticles (80 nm) sizes. The nanocomposites of WO3/SC-15 epoxy were prepared by infusion of 1 wt.%, 2 wt.% and 3 wt.% of porous WO3 nanoparticles into SC-15 epoxy resin by using a non-contact (Thinky) mixing technique. Finally the neat epoxy and nanocomposites were cured at room temperature for about 24 h in a plastic rectangular mold. The cured epoxy samples were removed and precisely cut into required dimensions and tested for their thermal and mechanical properties. The HRTEM and SEM studies indicated that the sonochemically modified porous WO3 nanoparticles dispersed more uniformly over the entire volume of the epoxy (without any settlement or agglomeration) as compared to the unmodified WO3/epoxy nanocomposites. 相似文献
19.
Melt processing of thermoplastic-based nanocomposites is the favoured route to produce electrically conductive or electrostatic dissipative polymer composites containing carbon nanotubes (CNT). As these properties are desired at low filler fractions, a high degree of dispersion is required in order to benefit from the intrinsic CNT properties. This study discusses the influence of screw configuration, rotation speed, and throughput on the residence time and specific mechanical energy (SME) and the resulting macroscopic CNT dispersion in polycaprolactone (PCL) based masterbatches containing 7.5 wt.% multi-walled carbon nanotubes (MWNT) using an intermeshing co-rotating twin-screw extruder Berstorff ZE25. 相似文献
20.
Petra Pötschke Timo Andres Tobias VillmowSven Pegel Harald BrünigKazufumi Kobashi Dieter FischerLiane Häussler 《Composites Science and Technology》2010
Poly(lactic acid) (PLA)/multi-walled carbon nanotube (MWNT) composites were melt spun with different take-up velocities (max. 100 m/min) to obtain electrically conductive fibres. The incorporation of MWNT contents between 0.5 and 5.0 wt.% was realised in a previous melt mixing process using twin-screw extrusion. The relative resistance change of the fibres caused by contact with different solvents (water, n-hexane, ethanol, methanol) and solvent concentrations was used as liquid sensing response, whereas the time dependent resistance was recorded during immersion and drying cycles. Transmission electron microscopy and Raman spectroscopy indicated enhanced orientation of MWNT along the fibre axis with take-up velocity, resulting in decreased sensitivity during solvent contact. Additionally, sensitivity decreased as the weight content of MWNT increased and was furthermore dependent on the characteristics of used solvents. In context with the targeted application of leakage detection, fibres with low MWNT amount and low draw down ratio (as extruded fibres with 2 wt.% MWNT) are suitable, as they showed relative resistance changes of up to 87% after 10 min immersion in methanol even if the recovery upon drying was suppressed significantly. 相似文献