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1.
Investigation of rheological and mechanical properties of wood flour reinforced polypropylene
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This study aims to investigate the rheological and mechanical properties of polypropylene when reinforced by wood flour. In the study, wood flour (WF) was added as filling material to polypropylene (PP), and its effects were investigated. The grain size of the wood flour was 300 μm. Wood flour was mixed into polypropylene material at different rates of weight. Viscosity changes of the polypropylene at various temperatures and pressure values of the concentration rates were documented. As a result, viscosity increases as the amount of wood flour filling is increased; yet as temperature, pressure and shear rate are increased, viscosity decreases. The study also focuses on the changes in its mechanical properties of polypropylene reinforced with wood flour. The tensile strength of reinforced polypropylene at varying percentages (wt. 5 %, wt. 10 % and wt. 15 %) was observed to decrease by 11 %, 16 % and 21 %, respectively, compared to that of non‐reinforced polypropylene. Additionally, impact tests showed that the highest energy absorption was in 10 % wood flour reinforced polypropylene. 相似文献
2.
Influence of Carbon Nanofiber Addition on Mechanical Properties and Crystallization Behavior of Polypropylene 总被引:2,自引:0,他引:2
Xin TONG ) Yong CHEN) Huiming CHENG)) Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang China) Materials Science & Engineering College Shenyang Ligong University Shenyang China 《材料科学技术学报》2005,21(5):686-690
1.IntroductionOne of the important applications for carbon nan-otubes(CNTs)is to be used as reinforcing filler,becauseCNTs have unique mechanical properties and large as-pect ratio.Various polymers have been used as the ma-trices to investigate the reinforcing effect of CNTs[1~5].Poly(propylene)(PP)as a common plastic and semicrys-talline polymer has attracted much attention in the re-search of CNT/polymer composites,including the influ-ence of GNTs on the mechanical properties[6~10],cr… 相似文献
3.
Ilaria Armentano Costantino Del Gaudio Alessandra Bianco Mariaserena Dottori Francesca Nanni Elena Fortunati Josè Maria Kenny 《Journal of Materials Science》2009,44(18):4789-4795
Composite materials based on poly(ε-caprolactone) (PCL) and carbon nanofibres (CNFs) were processed by solvent casting and
electrospinning. The main objective was to investigate the effects of the CNFs on the microstructural, thermal and mechanical
properties of the PCL matrix composites processed by two different routes. The hybrid materials obtained with different CNF
content (1, 3 and 7 wt%) were analysed by electron microscopy (FESEM), differential scanning calorimeter (DSC), thermogravimetry
(TGA) and mechanical testing. The composite films showed a good dispersion in the PCL matrix while electrospun samples were
consisted of homogeneous and uniform fibres up to 3 wt% CNFs with average fibre diameter ranged between 0.5 and 1 μm. Composite
films and mats revealed an increased crystallization temperature with respect to the neat PCL matrix. Mechanical properties
of solvent cast films and electrospun mats were assessed by uniaxial tensile tests. A stiffness increase was achieved in PCL
films depending on the CNF content, while mechanical properties of mats were only slightly affected by CNF introduction. 相似文献
4.
《Composites Part A》2002,33(1):43-52
Short bamboo fiber reinforced polypropylene composites (BFRP) and short bamboo–glass fiber reinforced polypropylene hybrid composites (BGRP) were fabricated using a compression molding method. Maleic anhydride polypropylene (MAPP) was used as a compatibilizer to improve the adhesion between the reinforcements and the matrix material. By incorporating up to 20% (by mass) glass fiber, the tensile and flexural modulus of BGRP were increased by 12.5 and 10%, respectively; and the tensile and flexural strength were increased by 7 and 25%, respectively, compared to those of BFRP. Sorption behavior and effects of environmental aging on tensile properties of both BFRP and BGRP systems were studied by immersing samples in water for up to 1200 h at 25°C. Compared to BFRP, a 4% drop in saturated moisture level is seen in BGRP. After aging in water for 1200 h, reduction in tensile strength and modulus for BGRP is nearly two times less than that of BFRP. Use of MAPP as coupling agent in the polypropylene matrix results in decreased saturated moisture absorption level and enhanced mechanical properties for both BFRP and BGRP systems. Thus it is shown that the durability of bamboo fiber reinforced polypropylene can be enhanced by hybridization with small amount of glass fibers. 相似文献
5.
The effect of up to 2 wt% of “as received” carbon nanofiber (CNF) loading on the microstructural, physical, and mechanical (compressive and splitting tensile strengths) properties of hybrid CNF/silica fume cement composites has been studied. Silica fume (SF) facilitated CNF dispersion due to its small particle size and improved the interfacial interaction between the CNFs and the cement phases. The CNFs were found embedded as individual fibers throughout the paste and self-aggregated as clumps in pockets. Mechanically, the CNFs embedded in the paste and at the pocket edges acted to offset the effect of defects created by the pockets. The addition of CNFs promoted pore refinement of the composites and increased the pore volume in the 6–200 nm pore diameter range, ascribed in part to interstitial pores between the entangled CNFs. 相似文献
6.
This study compares the mechanical and thermal properties of glassy and rubbery epoxy–matrix composites reinforced with 1 and 4 wt.% single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphite, and carbon nanofibers (CNFs). The tensile modulus of most glassy composites was higher than that of the epoxy and increased with higher filler concentration and 4% graphite/epoxy and 4% SWCNT/epoxy exhibited approximately the same highest tensile modulus. The elongation of glassy composites was significantly lower than that of the epoxy and decreased with increasing filler loading. Most rubbery composites showed a higher tensile modulus and elongation than the epoxy and the modulus increased with rising filler content and 4% SWCNT/epoxy showed the highest tensile modulus and tensile strength. In the rubbery regime, glassy and rubbery composites displayed a higher storage modulus than the corresponding epoxy and 4 wt.% SWCNT/epoxy composites showed a 300% improvement in storage modulus compared to the epoxy. 相似文献
7.
《Composites Part B》2007,38(2):152-158
The mechanical properties of newly developed aspen fiber–polypropylene composites (APC) were experimentally explored and numerically predicted at the temperatures and humidity that are typical for domestic housing applications. The mechanical properties of APCs with five different fiber-loadings were evaluated at the room temperature, 4 °C, and 40 °C. Environmental effects on the mechanical properties of APCS were experimentally quantified after conditioning the APCs with two different fiber-loadings in the following temperature and humidity for over 7000 h: (1) hot/dry at 40 °C and 30% relative humidity (RH), (2) hot/wet at 40 °C and 82% RH, (3) cold/dry at 4 °C and 30% RH, and (4) cold/wet at 4 °C and 82% RH. The tensile moduli, flexural moduli, and the flexural strength increased as the woodfiber content increased in the composites. However, the tensile strength decreased as the fiber content increased. The tensile strength was shown to slightly improve with an addition of a coupling agent between the aspen fibers and polypropylene. The simple empirical micromechanics Halpin–Tsai model for randomly distributed short fiber reinforced composites was employed to predict the homogenized elastic moduli of APC, by optimizing the interfacial model parameter. Scanning electron microscopy (SEM) micrographs confirmed that an addition of the adhesion promoter maleated anhydride polypropylene (MAPP) between the aspen fibers and polymeric matrix improved the interfacial bonding. 相似文献
8.
In this study, the mechanical properties and structure orientation of pure polyamide 1212 (PA1212) were compared with those of PA1212–carbon nanofibers (CNFs) nanocomposites. The tensile strength of the composite containing 0.3 wt.% modified CNFs was improved from 328 MPa (pure PA1212) to 373 MPa after drawing. The reinforcing effect was investigated in terms of crystallization behavior, crystal morphology, alignment of CNFs, and crystal orientation degree. Spherulites developed into oriented crystals after drawing, and the CNFs aligned along the drawing direction. The heterogeneous nucleation effect of the aligned CNFs improved the crystal orientation degree, which produced the reinforcing effect. The oriented fibril structures with rigid nanofibers acting as nuclei reinforced the entire oriented crystals in the composites. 相似文献
9.
Hydrophobic cellulose nanofibers (CNFs) were prepared by surface modification using alkenyl succinic anhydride (ASA). The hydrophobicity of CNFs was varied by changing the degree of substitution (DS) from 0 to 0.83. Modified CNFs were mixed with high-density polyethylene (HDPE) using a twin-screw extruder and the resulting composites were injection molded. The tensile properties initially improved with increasing DS up to ∼0.3–0.5, and then decreased with further substitution. The tensile strength and modulus of 10 wt.% HDPE/CNF composites containing 8.8 wt.% ASA (DS: 0.44) were 43.4 MPa and 1.97 GPa, respectively. These values were both almost 70% higher than those of composites containing unmodified CNF, and 100% and 86% higher, respectively, than those for pure HDPE. X-ray computed tomography measurements showed that CNFs modified with a DS of 0.44 were dispersed uniformly within the resin matrix, whilst unmodified CNFs and those modified with a DS of 0.77 agglomerated within the composites. 相似文献
10.
11.
In this study, we report a novel, eco-friendly and simple method to fabricate cellulose nanofibers (CNFs)/silver nanowires (AgNWs)/acrylic resin (AR) composite electrode. CNFs with average diameter of 15 nm were disintegrated only by one time-pass grinding. Aqueous dispersion of AgNWs was embedded onto the surface of CNFs film by simple vacuum filtration. The final composite electrode was obtained by impregnating CNFs/AgNWs film to AR with the assist of adhesive tape. This electrode with AgNWs density of 134 mg/m2 showed low sheet resistance (4 Ω/sq), and high light transmittance (85%) which was 6% lower than that of neat AR. The coefficient of thermal expansion of the composite electrode was as low as 25.32 ppm K−1. The tensile strength and Young’s modulus of CNFs/AgNWs/AR composite film were 35.71 MPa and 1.63 GPa, which were about 8 and 5.8 times larger than neat AR film, respectively. 相似文献
12.
The objective of this study was to investigate the incorporation of poplar wood fibers both with and without a novel coupling agent, alkyl ketene dimer (AKD), on the mechanical properties of wood fiber/polypropylene (PP) composites. The resulting properties were compared to those obtained with the most commonly used coupling agent, maleic anhydride grafted PP (MAPP). Tensile and impact strengths of the composites decreased with increasing poplar wood fibers content. Tensile modulus of the composites increased by the incorporation of the wood fibers content up to 70 wt% but further increment in the wood fibers decreased the tensile modulus. At the constant content of poplar wood fibers (70 wt%), the tensile strength determined for the coupled composites with 5% AKD increased by 41% in comparison with the non-coupled composites while the tensile modulus increased by 45%, the impact strength of the coupled composites increased by 38%. The performance of 5% AKD on the mechanical properties of the composites is a little better than 3% MAPP. The good performance of 5% AKD is attributed to the enhanced compatibility between the poplar wood fibers and the polymer matrix. The increase in mechanical properties of the composites demonstrated that AKD is an effective coupling agent for wood fiber/PP composites. 相似文献
13.
A mixture design was used in experiments, to determine the optimal mixture for composites of rubberwood flour (RWF) and reinforced recycled polypropylene (rPP). The mixed materials were extruded into panels. Effects were determined of the mixture components rPP, RWF, maleic anhydride-grafted polypropylene (MAPP), and ultraviolet (UV) stabilizer, on the mechanical properties. The overall composition significantly affected flexural, compressive, and tensile properties. The fractions of recycled polypropylene and rubberwood flour increased all the mechanical material properties; however, increasing one fraction must be balanced by decreasing the other, and the rubberwood flour fraction had a higher effect size. The fraction of MAPP was best kept in mid-range of the fractions tested, while the UV stabilizer fraction overall degraded the mechanical properties. Our results suggest that the fraction of UV stabilizer should be as small as possible to minimize its negative influences. The models fitted were used for optimization of a desirability score, substituting for the multiple objectives modeled. The optimal formulation found was 50.3 wt% rPP, 44.5 wt% RWF, 3.9 wt% MAPP, 0.2 wt% UV stabilizer, and 1.0 wt% lubricant; the composite made with this formulation had good mechanical properties that closely matched the model predictions. 相似文献
14.
Jianli Kang Philip Nash Jiajun Li Chunsheng Shi Naiqin Zhao Sijie Gu 《Journal of Materials Science》2009,44(20):5602-5608
The effect of heat treatment of carbon nanofibers (CNFs) on the mechanical properties of CNF (Ni/Y)–Cu composites was investigated.
CNF (Ni/Y)–Cu composite powder mixtures were prepared by a combination of in situ chemical vapor deposition (CVD) and co-deposition
processes. The in situ CNF (Ni/Y)–Cu powder synthesized by CVD was subject to heat treatment at temperatures ranging from
700 to 1,000 °C. The morphology and quality of CNFs were characterized by transmission electron microscope, scanning electron
microscope, and Raman spectroscopy. Heat treatment can improve the CNFs by eliminating the amorphous carbon and disordered
graphite. Bulk composites containing various fractions of CNFs were fabricated from the powder by cold pressing and sintering
followed by repressing. With the same fraction of CNFs (2.5 wt%), the strengthening efficiency of the CNFs heat treated at
800 °C is 88% higher than that of as-synthesized CNFs. The strengthening mechanism of CNFs in the composites is discussed
in detail. 相似文献
15.
Fabrication of the new structure high toughness PP/HA-PP sandwich nano-composites by rolling process
In this study a designed rolling setup was used to fabricate new structure polypropylene/hydroxyapatite-polypropylene (PP/HA-PP) sandwich nano-composites. To check the effect of rolling process and PP layers content on the structure and mechanical properties of these sandwich composites, different mechanical tests and analysis were performed on these composites. Results of tensile, bending and buckling tests show the rolling process improves the strength, modulus and flexural rigidity of composites significantly while with increasing the PP layers content from 10 vol.% to 20 vol.% decreases the stiffness, flexural rigidity and modulus of composites slightly. Results of impact test demonstrate the rolling process and increasing the volume percentage of the PP layers in sandwich composites cause a dramatic improve in impact absorbed energy of the PP/HA-PP sandwich composites. The results of Differential Scanning Calorimetry (DSC) analysis confirm the rolling process increases the crystallinity and molecular alignment of polypropylene in composites. The results of mechanical tests and DSC analysis show the increasing of polypropylene molecular alignment by rolling process is the most dominant reason of improvement the mechanical properties of sandwich composites. 相似文献
16.
纳米纤维素/聚乳酸复合包装薄膜的制备及表征 总被引:3,自引:3,他引:0
目的添加适量的纳米纤维素改善聚乳酸的脆性,以适应产品的包装。方法将聚乳酸(PLA)与纳米纤维素(CNFs)共混制备复合包装材料,测试该复合材料的力学性能、透光率、红外谱图,并用扫描电子显微镜(SEM)观察了复合包装材料的表面形貌。结果纳米纤维素添加到聚乳酸中增加了其力学性能,当纳米纤维素质量分数为2%时,拉伸强度和冲击强度都达到最大;随着添加CNFS比例的增大,CNFs/PLA复合薄膜材料的透光率随之降低,雾度随之升高,但是该薄膜作为包装材料对商品的可视性影响不大。结论纳米纤维素(CNFs)是具有一定长径比的纳米级线状材料,对材料的拉伸强度具有增强作用。 相似文献
17.
SPTW 对聚丙烯复合材料力学性能的影响 总被引:3,自引:2,他引:1
目的研究六钛酸钾晶须添加量的不同对聚丙烯复合材料力学性能的影响。方法采用硅烷偶联剂KH550改性六钛酸钾晶须(SPTW),利用熔融共混法,将改性过的六钛酸钾晶须与聚丙烯(PP)、马来酸酐接枝聚丙烯(PP-g-MAH)熔融共混制得PP/PP-g-MAH/SPTW复合材料。结果比较不同含量的六钛酸钾晶须对复合材料力学性能的影响,发现添加适量改性过的六钛酸钾晶须可明显改善复合材料的力学性能。随着六钛酸钾含量的不断增加,其弯曲强度也增大,当SPTW的质量分数为12%时,弯曲强度提高了21.5%,随着含量的继续增加,弯曲强度开始下降;其拉伸强度和冲击强度都呈先增加后降低的趋势,在SPTW质量分数为8.3%左右时,其拉伸强度和冲击强度分别提高了19.7%和31.8%。结论在聚丙烯中添加经硅烷偶联剂KH550改性的SPTW,其质量分数为12%时,力学性能最佳。 相似文献
18.
Geotextiles are generally made from natural or synthetic fibers and both fibers offer their own advantages and disadvantages for geotechnical applications. In this study, the jute fibers were treated with 4 wt.% sodium hydroxide (NaOH) solution in order to enhance their tensile properties. A series of needlepunched nonwoven geotextiles were then fabricated by formulating blends of untreated jute and polypropylene fibers and corresponding sets of nonwovens containing alkali treated jute and polypropylene fibers in defined weight proportions. Subsequently, a comparison has been made between the physical and mechanical properties of these blended nonwoven geotextiles. In general, the alkali treated jute blended nonwoven geotextiles offer higher puncture resistance in addition to higher tensile and tearing strengths in the cross-machine (preferential) direction than their corresponding blended geotextiles consisting of untreated jute fibers. Blended nonwoven geotextiles consisting of more than 40 wt.% jute fibers were not found to be useful in enhancing the mechanical properties. 相似文献
19.
Effect of carbon nanofibers (CNFs) content on thermal and mechanical properties of CNFs/SiC nanocomposites 总被引:1,自引:0,他引:1
Carbon nanofibers dispersed β-SiC (CNFs/SiC) nanocomposites were prepared by hot-pressing via a transient eutectic phase route at 1900 °C for 1 h under 20 MPa in Ar. The effects of additional CNFs content between 1 and 10 wt.% were investigated, based on densification, microstructure, thermal and mechanical properties. The CNFs/SiC nanocomposites by the CNFs contents below 5 wt.% exhibited excellent relative densities over 98% with well dispersed CNFs. However, the CNFs/SiC nanocomposites containing the CNFs of 10 wt.% possessed a relative density of 92%, accompanying CNFs agglomerates and many pores located inside the agglomerates. The three point bending strength gradually decreased with the increase of CNFs content, but the indentation fracture toughness increased to 5.7 MPa m1/2 by the CNFs content of 5 wt.%. The thermal conductivity was enchanced with the increase of CNFs content and represented a maximum value of 80 W/mK at the CNFs content of 5 wt.%. 相似文献
20.
The effects of carbon nanofibres (CNFs) on the mechanical performance and healing efficiency of self-healing epoxy/poly(ε-caprolactone) (PCL) blends were examined. Through a simple polymer blending process, phase-separated epoxy/PCL blends were prepared, which showed self-healing capability upon thermal activation. The introduction of CNFs into a co-continuous phase-structured epoxy/PCL system, at the content of as low as 0.2 wt.%, has been found to yield combinational improvements in the flexural strength, tensile strength, toughness and hardness with no adverse effect on the self-healing performance. Significantly enhanced mechanical performance by low content of CNFs enables the development of epoxies and advanced polymer composites with longer service life and less maintenance. 相似文献