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1.
Regenerated cellulose‐saponite nanocomposite films were prepared from LiOH/urea solutions, and exhibited high optical transparency and flexibility. The saponite platelets formed intercalated nanolayered structures in the composites. The longitudinal directions of both the cellulose II crystallites and the saponite platelets were preferentially oriented parallel to the film surface in the composites. The good nanodispersibility and high orientation of the saponite platelets in the composite films resulted in high mechanical strength, high Young's modulus, and good thermal dimensional stabilities, and gas barrier properties in the composites, compared with a reference cellulose film. Moreover, the tensile strength and Young's modulus of the composite film reached 241 MPa and 7.7 GPa, respectively, when a simple drawing process was applied to the wet composite film; this is probably owing to the improvement in the orientation of the cellulose II crystallites and saponite platelets in the composites. The composite films also showed high toughness and ductility. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3168–3174, 2013 相似文献
2.
Amitava Bhattacharyya Sohel Rana Shama Parveen Raul Fangueiro Ramasamy Alagirusamy Mangala Joshi 《应用聚合物科学杂志》2013,129(5):2383-2392
The present article reports the development and characterization of carbon nanofiber (CNF)‐incorporated carbon/phenolic multiscale composites. Vapor‐grown CNFs were dispersed homogeneously in to phenolic resin using an effective dispersion route, and carbon fabrics were subsequently impregnated with the CNF‐dispersed resin to develop carbon fiber/CNF/phenolic resin multiscale composites. Mechanical and thermal transmission properties of multiscale composites were characterized. Elastic modulus and thermal conductivity of neat carbon/phenolic and multiscale composites were predicted and compared with the experimental results. It was observed that incorporation of only 1.5 wt % CNF resulted in 10% improvement in Young's modulus, 12% increase in tensile strength, and 36% increase in thermal conductivity of carbon/phenolic composites. Fracture surface of composite samples revealed the formation of stronger fiber/matrix interface in case of multiscale composites than neat carbon/phenolic composites. Enhancement of above properties through CNF addition has been explained, and the difference between the predicted values and experimental results has been discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
3.
P. A. Mahanwar Suryasarathi Bose Abhishek Venkatesh Tirumalai 《Polymer-Plastics Technology and Engineering》2013,52(5):597-600
Particle-filled polymer composites have become attractive because of their wide applications and low cost. Various factors influence the mechanical properties of thermoplastic composites. Of these, the aspect ratio of the reinforcement, interfacial adhesion, and binder content are the most important. Other than these, the particle size and particle size distribution of the reinforcement also influence the mechanical properties. In this paper, injection molded mica composites were investigated, using nylon-6 as a binder. Many models are available to predict the Young's modulus of the composites. A theoretical model for Young's modulus by Lewis and Nielsen was used to predict the Young's modulus of the composites. Tetra isopropyl titanate (TYZOR® TPT) was used to modify the adhesion between the reinforcement and the binder by mixing it with the reinforcement prior to compounding. It was found that Young's modulus was greater than the predicted values. 相似文献
4.
Elastic and plastic properties of epoxy resin syntactic foams filled with hollow glass microspheres and glass fibers
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Representative volume elements of syntactic foams with a random filling of short glass fibers and hollow glass microspheres in epoxy resin were established by a random sequential adsorption method. The fiber volume fraction was set at 4%, and the microsphere volume fraction range was from 5 to 30%. This numerical simulation was studied with ANSYS software. The influence on the elastic and plastic mechanical properties of syntactic foams of the microsphere volume fraction and relative wall thickness were investigated, and the plastic strain evolution process in the composites was analyzed. The results show that the compressive yield limit and Young's modulus values of the syntactic foams decreased with increasing microsphere volume fraction when the microsphere relative wall thickness was 0.02, but these properties were enhanced with increasing microsphere volume fraction when the relative wall thickness exceeded 0.04. The specific strength and tangent modulus values of the composites increased with increasing microsphere volume fraction. In addition, we observed that the yield stress, Young's modulus, and tangent modulus values of the syntactic foams were obviously enhanced by the addition of glass fibers. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44188. 相似文献
5.
Syndiotactic polypropylene (SPP)/ethanol swelled microfibrous cellulose (MFC) composite was prepared by a melting mixer, and its morphology and tensile properties were studied. The scanning electron microscope microphotograph did not show the aggregated MFC part up to the 40 wt % MFC loading content, and the Young's modulus was exponentially increasing with the increase of the MFC loading content. These results suggested that the MFC was well‐dispersed in the SPP matrix by an ethanol surfactant work. The Young's modulus was much higher than that of the composite with commonly used fibrous cellulose and moreover, exceeded the theoretical one obtained from the Halpin‐Tsai equation. The differential scanning calorimetry and wide‐angle X‐ray diffraction measurements showed that the MFC acted as a good α‐nucleation agent for SPP. It was found that the excessive Young's modulus of the MFC composite was originated from an increase of that of the SPP matrix induced by the α‐nucleation effect. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
6.
Poly(ε-caprolactone) (PCL) is one of the ecofriendly biodegradable polymers with excellent moldability but with rather low mechanical properties especially for the industrial and biomedical use. In this research, to overcome the problem, the two types of cellulose nanofibers, the cellulose acetate nanofibers (CA-NF) and the cellulose nanofibers (C-NF), were composited into PCL for the enhancement of the mechanical properties of PCL. CA-NF were prepared by electrospinning and converted into C-NF afterward by deacetylation. It was found that the Young's modulus of the CA-NF/PCL composite at the fiber concentration of 35 wt% significantly increased by ~3 times as compared with that of neat PCL, whereas C-NF/PCL of the same fiber concentration also increased by ~4.5 times. It was also found that the Young's moduli of CA-NF/PCL nearly reached the theoretical values calculated by the equation suggested by Tsai, but that the Young's moduli of C-NF/PCL could not reach the theoretical values. It indicates that CA-NF possessed better compatibility with PCL than C-NF, agreeing well with the fracture-surface analyses of the two composites by the scanning electron microscopy. 相似文献
7.
E. López-López J.P. Erauw R. Moreno F. Cambier C. Baudín 《Journal of the European Ceramic Society》2013,33(15-16):3195-3200
Zirconium titanate-zirconia composites have potential for applications involving variations of temperature. Elastic characterization is necessary to evaluate stresses developed in materials which may be used in these kinds of applications. In this work, Young's and shear modulus and Poisson's ratio of two zirconium titanate-zirconia bulk composites (Z(Y)T70 and Z(Y)T50) have been determined at room temperature by the Impulse Excitation Technique (IET). Furthermore, Young's modulus (E) has been determined at high temperature (up to 1400 °C) for both composites. Young's modulus of Z(Y)T70 composite decreases ≈6% between room temperature and 400 °C due to the presence of zirconia. From 400 to 1400 °C, the decrease of E (≈14%) is due to the presence of zirconium titanate. Young's modulus behaviour at high temperature of Z(Y)T50 composite is determined by the degree of microcrack healing, which depends on the maximum temperature reached. 相似文献
8.
The article reports the results of studies on the effect of chitosan (0, 5, 10, 20, 30, and 40 wt %) on thermal and mechanical properties of poly(hydroxybutyrate) composites. The addition of chitosan causes an increase in the glass transition temperature (Tg) while a decrease in the enthalpy of fusion (ΔHfus), crystallization (ΔHcry) and percentage of crystallinity as determined by differential scanning calorimeter (DSC). The thermogravimetric analysis reveals that high amount of chitosan decreases the thermal stability of the composites. The Young's modulus of the composite increases and is high for the composite having 40 wt % of chitosan. Increase in the amount of chitosan decreases the elongation at break and impact strength of composites. Finally, the Young's modulus of the composites has been compared with the theoretical predictions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
9.
Effect of fiber compression on flexural modulus of the natural fiber composites was examined. The kenaf, bagasse, and polypropylene were mixed into pellets, and composites were fabricated by injection molding. To predict flexural modulus of the composites, the Young's modulus of kenaf and bagasse fiber were measured. Using the obtained Young's modulus, the flexural modulus of the composites was predicted by Cox's model that incorporates the effect of fiber compression. It was found that those fibers with high Young's modulus were more compressed than that with low Young's modulus. Moreover, the distribution of fiber length and orientation in the composites were also investigated. To calculate the orientation factor for the prediction model, the distribution function of fiber orientation was determined to a triangular function. The flexural modulus of the composites increased with increase of volume fraction. The predicted values were in good agreement with the experimental values. Furthermore, it was revealed by SEM that the porous structure of the natural fibers was compressed. The fiber compression ratio (3.6) in bagasse was higher than that in kenaf (1.4) due to the difference in porous structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 911–917, 2006 相似文献
10.
Sy Trek Sean 《Polymer-Plastics Technology and Engineering》2013,52(4):421-425
This paper deals with the effect of processing conditions on the mechanical properties of composite material made from newsprint and polystyrene. A masterbatch compound with weight ratio of 50:50 (polystyrene/fiber) was prepared using a Brabender intensive type mixer. Composites with various percentage of fiber, e.g., 40, 30, 20, and 10% of fiber were obtained by adding the measured amount of polymer to the masterbatch followed by another mixing period of time. Test samples were compression molded into shoulder-shaped test specimens, using a steam-heated press, and, kept in room conditioning at 23°C and 50% of relative humidity for a week 48 h prior to testing. The Young's modulus and the strength at break were evaluated, and the averages of six measurements were reported. Test results showed that newsprint loading level has a significant impact on mechanical performance of the resulting composites. Tensile strength increased at first linearly with newsprint content, then reached asymptote at higher level of newsprint content 40% or more. As the Young's modulus is concerned, there is a linear relationship between tensile Young's modulus and fiber concentration as proposed by the various models in the literature. 相似文献
11.
《Ceramics International》2017,43(5):4576-4582
This paper presents the effects of microfibre contents on mechanical properties of fly ash-based geopolymer matrices containing glass microfibres at 0, 1, 2 and 3 mass%. The influence of glass microfibres on the fracture toughness, compressive strength, Young's modulus and hardness of geopolymer composites are reported, as are the microstructural properties investigated using scanning electron microscopy. Results show that the addition of 2 mass% glass microfibres was optimal, exhibiting the highest levels of fracture toughness, compressive strength, Young's modulus and hardness. The results of the microstructural analysis indicate that the glass microfibres act as a filler for voids within the matrix, making a dense geopolymer and improving the microstructure of the binder. This leads to favourable adhesion of the composites, and produces a geopolymer composite with good mechanical properties, comparable to pure geopolymer. The failure mechanisms in glass microfibre-reinforced geopolymer composites are discussed in terms of microstructure. 相似文献
12.
Graphene oxide (GO) has attracted huge scientific interest due to its unique physical and chemical properties as well as its wide‐scale applicability including facile synthesis and high yield. Here, we report preparation of nanocomposites based on GO and unsaturated polyester resin (PE). The synthesized samples were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and tensile strength measurements. A good dispersion of the GO sheets within the resin matrix was observed from the morphological analysis. A significant enhancement in mechanical properties of the PE/GO composites is obtained at low graphene loading. Around 76% improvement of tensile strength and 41% increase of Young's modulus of the composites are achieved at 3 wt % loading of GO. Thermal analysis of the composite showed a noticeable improvement in thermal stability in comparison to neat PE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
13.
Jia Xin Chan Joon Fatt Wong Azman Hassan Norhayani Othman Jeefferie Abd Razak Umar Nirmal Shahrir Hashim Yern Chee Ching Muhamad Zaini Yunos Ridwan Yahaya T. M. Sampath U. Gunathilake 《应用聚合物科学杂志》2023,140(6):e53463
Polybutylene terephthalate (PBT) composites were prepared with 1.0 phr synthetic wollastonite nanofibers (SWN), natural wollastonite (NW) and graphene oxide (GO) to study the effect of different fillers on mechanical, thermal, tribological, and flammability properties. The properties of PBT composites are related to the size, structure, and interfacial adhesion of the fillers in PBT matrix. PBT/SWN demonstrated the highest tensile strength and Young's modulus (6% and 9% increment), followed by PBT/NW (1.3% and 7% increment) and PBT/GO (2% decrement and 4% increment). PBT/SWN gave the highest degradation temperature (409°C), followed by PBT/GO (404.7°C). The maximum enhancement in wear resistance (73%) by PBT/SWN and anti-friction performance (26%) by PBT/GO evinced the excellent load-bearing ability of SWN and the great lubricating effect of GO. PBT/NW had the lowest peak heat release rate, smoke, and carbon dioxide production rate. This study shows that PBT composites have great potential in different automotive applications. 相似文献
14.
Jian Zhao Yanlei Liu Jianglong Cheng Shengming Wu Zhaobo Wang Haiqing Hu Chunhua Zhou 《Polymer International》2017,66(12):1827-1833
Solvent‐exfoliated graphene (SEG)‐reinforced polystyrene (PS) composites were prepared using a straightforward solution‐casting method. SEG sheets, obtained by sonication‐assisted solvent direct exfoliation from natural graphite, were well dispersed in the PS matrix as evidenced from scanning electron microscopy and transmission electron microscopy observations. Addition of 0.5 wt% SEG resulted in a 6% increase in tensile strength and a 77% improvement in Young's modulus over pure PS due to the effective load transfer between SEG and PS matrix. The Young's moduli of the PS/SEG composites were obtained from both tensile experiments and calculations using the well‐established Halpin–Tsai model. Results from dynamic mechanical analysis indicated that the storage modulus of the PS/SEG composites was significantly improved relative to neat PS. The glass transition temperatures of the composites were found to increase substantially upon addition of SEG, consistent with differential scanning calorimetry analysis. © 2017 Society of Chemical Industry 相似文献
15.
Khaled Labidi Zhi Cao Montassar Zrida Alan Murphy Ahmed Hichem Hamzaoui Declan M. Devine 《应用聚合物科学杂志》2019,136(18):47392
Alfa fiber/polypropylene composites were manufactured using twin-screw extrusion. Fibers were extracted using alkaline and steam explosion methods. Three chemical treatments were also applied to the alkaline-extracted fibers: stearic acid (SA), and potassium permanganate dissolved in water (KW) and in acetone (KA). Finally, thermal annealing was applied to the composites. The results indicate that composites with steam-exploded fibers had a significantly higher melt flow index than composites with alkaline-extracted fibers. Moreover, the incorporation of fibers into the matrix increased the Young's modulus, where the optimum results were obtained utilizing the alkaline-extracted fibers. Both extraction methods also significantly decreased the water uptake, especially the steam explosion. The three chemical treatments increased the melt flow index and conversely decreased the tensile strength and Young's modulus. In addition, KW treatment decreased the water uptake. Finally, thermal annealing increased the tensile strength and Young's modulus of composites with SA-treated fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47392. 相似文献
16.
Rafel Reixach Francesc X. Espinach Elena Franco‐Marqus Francisco Ramirez de Cartagena Neus Pellicer Josep Tresserras Pere Mutj 《Polymer Composites》2013,34(11):1840-1846
Stiffness is one of the most relevant properties of composite materials. Although fiberglass has been traditionally used as reinforcement, natural fibers are seen as possible replacements due to concerns for environmental protection. In this work fibers from orange tree prunings were prepared and converted into mechanical, thermomechanical and chemi‐thermomechanical pulps, to be used as reinforcement for polypropylene. Polypropylene composite materials with 20–50% of reinforcing fibers were prepared and mechanically characterized. The intrinsic Young's modulus of the fibers was back calculated by means of the Hirsch model. The moduli were also obtained by Halpin‐Tsai equations with Tsai‐Pagano methods and then compared to establish the influence of the aspect ratio. Finally, a fiber tensile modulus factor was defined in order to characterize the contribution of the fibers to the Young's moduli of the composites. POLYM. COMPOS., 34:1840–1846, 2013. © 2013 Society of Plastics Engineers 相似文献
17.
The morphology and the tensile properties of unreinforced and short carbon fibre (SCF) reinforced Nylon 6/multiwalled carbon nanotube (MWCNT)-composites are investigated. The morphology analysis shows that MWCNT and SCF are randomly oriented in the composites. Furthermore, the SCF fail due to fibre pull-out, while the MWCNT fail due to fracture. Young's modulus and tensile strength of SCF reinforced Nylon 6 and Nylon 6/MWCNT-composites increase with increasing total filler volume content. Replacing SCF by MWCNT further enhances Young's modulus and the tensile strength. An additive modelling approach leads to better results at low MWCNT-volume contents, while at higher MWCNT loadings a multiplicative modelling approach results in a better approximation of the experimental data. Thus the SCF reinforced Nylon 6/MWCNT-composites behave at low MWCNT-volume contents like a polymer composite containing two different types of fillers, while at higher MWCNT loadings a behaviour of a short fibre reinforced nanocomposite is observed. 相似文献
18.
《Ceramics International》2022,48(16):23096-23103
Hydroxyapatite (HAp) is the most common bioactive ceramic used to replace hard tissue in the body. Because of its low resistance and fragile nature, more attention is being given to composites based on HAp such as HAp/TiO2 composites. This study aims at reporting the synthesis of HAp/TiO2 composites (hereafter named HT composite) by sol-gel and co-precipitation methods assisted by ultrasonic radiation. The structural characterization was carried out by X-ray Diffraction (XRD) and Scanning Transmission X-ray Microscopy (STXM) techniques using synchrotron radiation, which allowed a mixture of phases to be identified separately in the two materials once the composite was formed. A Rietveld refinement for XRD data determined the phase percentage and structural parameters obtained for each material. In addition, crystallite size using the modified Scherrer equation was determined. A piezoelectric character of the two materials was confirmed by Piezoresponse Force Microscopy (PFM) to determine the piezoelectric coefficient (deff). Finally, PinPoint-AFM force curves confirmed an increase in the Young's modulus value for the HT composite. 相似文献
19.
Istvánné Ráthy Ákos Kuki Jenö Borda György Deák Miklós Zsuga Kálmán Marossy Sándor Kéki 《应用聚合物科学杂志》2012,124(1):190-194
In this article, we report on the preparation and characterization of novel poly(vinyl chloride) (PVC)–carbon fiber (CF) composites. We achieved the reinforcement of PVC matrices with different plasticizer contents using unidirectional continuous CFs by applying a warm press and a cylinder press for the preparation of the PVC–CF composites. We achieved considerable reinforcement of PVC even at a relatively low CF content; for example, the maximum stress (σmax) of the PVC–CF composite at a 3% CF content was found to be 1.5–2 times higher than that of the PVC matrix. There were great differences among the Young's modulus values of the pure PVC and PVC–CF composites matrices. The absolute Young's modulus values were in the range 1100–1300 MPa at a 3% CF content; these values were almost independent of the plasticizer content. In addition, we found a linear relationship between σmax and the CF content and also recognized a linear variation of the Young's modulus with the CF content. The adhesion of CF to the PVC matrix was strong in each case, as concluded from the strain–stress curves and the light microscopy and scanning electron microscopy investigations. The mechanical properties of the PVC–CF composites with randomly oriented short (10 mm) fibers were also investigated. At low deformations, the stiffness of the composites improved with increasing CF content. Dynamic mechanical analysis (DMA) was used to determine the glass‐transition temperature (Tg) of the PVC–CF composites. The high increase in the Young's modulus entailed only a mild Tg increase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
20.
《Journal of the European Ceramic Society》2007,27(11):3339-3344
The mechanical properties and microstructure of alumina-rich magnesium aluminate spinel/tungsten (14 and 22 vol.% W) composites obtained by hot press at 1650 °C under reducing conditions have been investigated. The R-curve for these composites was estimated by the indentation strength method and compared with that of the monolithic spinel obtained under similar conditions. Rising R-curve behavior was specially observed in the composites when tungsten content was higher. Other mechanical properties such as hardness, toughness, Young's modulus and bending strength, were also determined for both (composites and monolithic magnesium aluminate). Higher values of bending strength were found as the metal volume fraction increases in the composite. The metal content dependence of Young's modulus and Vickers hardness follow the rule of mixtures. Mechanical properties and specially toughness are influenced by the metal content and its grain size. 相似文献