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1.
Cetyl trimethyl ammonium bromide (CTAB) was used for the intercalation modification of nano-montmorillonite (MMT). The spectra of Fourier transform infrared spectrometer (FTIR) and X-ray diffraction (XRD) suggested that CTAB had intercalated into the layers of MMT. And the interlayer spacing of MMT increased from 1.198 to 3.616 nm. The thermogravimetric analysis (TGA) curves of organic montmorillonite (OMMT) showed three-step degradation. The scanning electron microscope (SEM) photographs showed that surface morphology of MMT remained unchanged. Then polyphenylene sulfide (PPS)/organic montmorillonite (OMMT) composites were prepared by melt blending. And composites were treated at 180 °C for 24 h. The results of SEM showed that OMMT had good dispersion behavior and adhesion with PPS. The results of differential scanning calorimetry (DSC) showed the addition of OMMT resulted in heterogeneous nucleation crystallization of PPS. The results of TGA showed there was a good improvement of the thermal stability of PPS. The FTIR and color measurement analysis showed the addition of OMMT could improve the thermal oxidation stability. 相似文献
2.
Polymer composites of polyamide 6,6 reinforced with short glass fiber were prepared by injection molding, conditioned under dry, 50 % relative humidity and wet. Investigations by DSC, DMA and tensile tests were conducted. FLD study showed that more fiber degradation occurred during processing of the composites with higher fiber loading. DSC analysis revealed that the incorporation of glass fiber and moisture into the PA 6,6 matrix resulted in a remarkable decrease in the degree of crystallinity. DMA results revealed the glass transition temperatures were sensitive to moisture absorption and their values moved to a lower temperature upon exposure to moisture. Incorporation of glass fiber into the polyamide 6,6 gave rise to a significant improvement in tensile modulus and tensile strength, while tensile strain was reduced. Exposure to different environments from dry to wet conditions resulted in a decrease in the strength and modulus, while tensile strains decreased. 相似文献
3.
Hye Jin Zo Seong Hwan Joo Tak Kim Pan Seok Seo Jin Hong Kim Jong S. Park 《Fibers and Polymers》2014,15(5):1071-1077
In this article, we demonstrated the preparation of carbon-fiber-reinforced composites using a polyamide 6 (PA6)/thermoplastic polyurethane (TPU) blend, in which the addition of TPU resulted in superior mechanical performances and increased thermal stability. According to various characterization techniques, these results are attributed to an enhanced adhesion and a homogeneous dispersion of long-carbon-fibers (LCFs) with TPU sizing in blended polymer matrix. Above all, dynamic-mechanical thermal analysis (DMTA) measurements clearly show that the dynamic storage modulus (E') of the blend composites is increased by threefold with temperature ranges below and above the glass transition temperature. The presence of LCFs in TPU systems induces effective fiber orientation, exhibiting simultaneous improvements in the tensile strength, flexural strength, and thermal stability. 相似文献
4.
The aim of this paper is to study the effect of fibre content on mechanical and morphological properties and thermal stability of roselle fibres (RFs) reinforced polyurethane (TPU) composites. The RF/TPU composites were prepared at difference fibre contents; 10, 20, 30, 40 and 50 wt% by melt mixed mixer and hot press at 170 °C. Mechanical (tensile, flexural and impact strength) and Thermogravimetric analysis (TGA) properties of RF/TPU composites were measured according to ASTM standard. Obtained results indicated that effect of fibre contents display improved tensile and flexural and impact strength properties. RF/TPU composites show the best mechanical and thermal properties at 40 wt% roselle fibre content. Scanning electron microscopy (SEM) micrograph of fractured tensile sample of the roselle composite revealed good fibre/matrix bonding. TGA showed that RF/TPU with difference fibre contents had improved thermal stability. 相似文献
5.
Thanate Ratanawilai Kamonchanok Nakawirot Arsiwan Deachsrijan Chatree Homkhiew 《Fibers and Polymers》2014,15(10):2160-2168
This study aims to investigate the effects of two types of wood flour; oil palm mesocarp flour (OMF) and rubberwood flour (RWF), and their particle sizes on mechanical, physical, and thermal properties of wood flour reinforced recycled polypropylene (rPP) composites. The composite materials were manufactured into panels by using a twin-screw extruder. The rPP composites based on RWF significantly showed higher flexural, tensile, and compressive properties (both strength and modulus) as well as hardness and thermal stability than those composites based on OMF for the same particle sizes. However, distribution of RWF in the rPP matrix was less homogeneous than that of the rPP/OMF composites. Furthermore, a decrease of the particle sizes of filler for the rPP/OMF or RWF composites increased the flexural, tensile, compressive, and hardness properties. Likewise, the thermal stability of both OMF and RWF composites were insignificantly affected by the particle sizes. 相似文献
6.
Organic fiber from animal waste was used for the development of environmentally friendly animal fiber based polyester composites using cow hair. The cow hair fibers were cut into 10 mm lengths to produce the needed short fiber for random dispersion in the matrix. Before use, some of the fibers were treated with sodium hydroxide for fiber surface modification while some were left as untreated. Composites were developed using predetermined proportions of the fibers in an open mould production process. Samples were formed into tensile and flexural shape in their respective moulds and were stripped off the moulds after curing while further curing was ensured for 27 days before testing. Tensile and flexural properties of the cow hair fiber reinforced polyester composites were evaluated from which it was discovered that the untreated fiber reinforced composites possess better enhancement of mechanical properties compared to the treated fiber reinforced composites and the unreinforced polyester material. Mathematical models for the tensile and flexural properties were developed using statistical packages and estimation using developed software. The developed models revealed high degree of correlation between the experimental values and the predicted values. This denotes that the models can be used to predict the mechanical properties of cow hair reinforced polyester composites for various reinforcement contents. 相似文献
7.
Byoung Chul Chun Tae Keun Cho Mi Hwa Chong Yong-Chan Chung David Martin Jihua Chen Jong-Shin Park 《Fibers and Polymers》2007,8(1):43-49
Nanocomposite of polyurethane (PU), Nylon66 (nylon), and montmorillonite (MMT) was prepared by a twin screw extruder, and
the dispersion of MMT and the mechanical properties of the nanocomposite were analyzed. Dimethyl hydrogenated tallow 2-ethylhexyl
ammonium modified Cloisite 25A (C25A) and methyl tallow bis-2-hydroxyethyl ammonium modified Cloisite 30B (C30B) were used
as MMT. XRD and TEM analysis indicated that the continuous melt mixing by a twin screw extruder was effective in MMT dispersion.
C30B having hydroxyl group on its surface has better dispersion than C25A in the PU/nylon matrix. Maximum stress and strain
at break were the maximum at 1 wt% MMT regardless of matrix composition, and decreased at higher MMT content. Best MMT dispersion
was also observed at 1 wt% MMT for the entire matrix composition. Aggregation of MMT occurred at MMT content higher than 1
wt%. Nylon addition also induced the aggregation of MMT because of the high polarity of nylon surface. Dispersion of MMT was
very important in improving the mechanical properties of PU/nylon nanocomposite. 相似文献
8.
Thermomechanical and mechanical properties of polycaprolactone/flax composites were investigated. The composites were prepared by melt mixing with three different filler loadings. Except from heating (to eliminate the moisture) no other procedures were applied to the raw materials, neither compatibilizer agent was used. The tensile and impact properties were evaluated and dynamic mechanical analysis was performed. Additionally the materials have been characterized by means of DSC technique. The resulting material reveal enhanced mechanical properties due to reinforcement caused by fibers and by high interfacial adhesion. 相似文献
9.
Wrya Mohammadi Aframehr Banafsheh Molki Pejman Heidarian Tayebeh Behzad Morteza Sadeghi Rouhollah Bagheri 《Fibers and Polymers》2017,18(11):2041-2048
In this study, the effect of calcium carbonate (CaCO3) nanoparticles on the barrier properties and biodegradability of polylactic acid (PLA) was investigated. For this purpose, nanocomposite films with various CaCO3 nanoparticle contents (0, 3, 5, 10, and 15 wt%) were prepared by solution casting method. The gas permeability of nitrogen (N2), oxygen (O2), and carbon dioxide (CO2) was evaluated through a constant volume and variable pressure apparatus at different pressures and temperatures. According to results, barrier properties were improved by loading CaCO3 nanoparticles up to 5 wt%, and the gas permeability of CO2, O2, and N2 was decreased from 1.4, 0.31, and 0.07 Barrer to 0.48, 0.095, and 0.019 Barrer, respectively. In addition, it was also observed that the gas permeability of samples was decreased by increasing feeding pressure and increased by enhancing temperature. Furthermore, morphological results confirmed the formation of agglomerations and large clusters over 5 wt% CaCO3 nanoparticles. Finally, the thermal properties and biodegradability of PLA were increased by employing CaCO3 nanoparticles. These results suggested PLA nanocomposites as favorable candidates for food packaging applications. 相似文献
10.
Bahram Khan Muhammad Bilal Khan Niazi Arshad Hussain Zaib Jahan 《Fibers and Polymers》2017,18(1):64-73
Biodegradable packaging is gaining much attention in food industry as the awareness on sustainability has increased. Thermoplastic starch is a possible alternative. This study evaluated the influence of malic acid (MA) and citric acid (CA), used as a plasticizer, on the mechanical properties of thermoplastic starch (TPS) obtained by spray drying. TPS powder was produced from solution spray drying. This powder was further compression molded to prepare TPS dog-bone test samples. X-ray Diffraction (XRD) results showed that both the spray dried TPS powder and dog-bone test samples were amorphous in nature irrespective of the amount of plasticizer added. Scanning electron microscope (SEM) was used to examine the morphology of solution spray dried TPS powder. No noticeable difference was observed in the morphology. Particles were spherical in shape with homogenous surface. The FT-IR analysis indicated the interaction of plasticizers with starch chains by hydrogen bonding. During TGA analysis, apart from moisture loss at 100 °C, samples were thermally stable up to 170 °C. Mechanical testing of TPS dog-bone revealed that sample containing malic acid as plasticizer exhibited a more elastic behavior as compared to citric acid plasticized formulations. It was revealed that the tensile strength of TPS dog-bone samples was inversely proportional to the quantity of plasticizer used. 相似文献
11.
A series of polyurethane (PU)/monmorillonite (MMT) or nylon 66/MMT nanocomposite were prepared by melt-compounding method
to take a close look at the MMT dispersion in the nanocomposite depending on the polymer matrix and the compatibilizer content.
Cloisite 30B, the brand name, was selected as MMT, because surface was covered with methyl tallow bis-2-hydroxyethyl ammonium
group and the reduced surface hydrophilicityity rendered MMT dispersed better in polymer matrix compared to bare MMT. MMT
dispersion, due to the difference in hydrophilicity and the fondness of similar hydrophilicity, was better in nylon than PU.
Maximum stress and tensile modulus could be increased by the control of MMT content for both nylon and PU, and the compatibilizer,
when added at the same MMT content, also could increase the tensile properties of both nylon and PU. It was found from this
investigation that the good dispersion of MMT in polymer matrix can improve the mechanical properties of nanocomposite. 相似文献
12.
Sisal fibres were subjected to a 2 % sodium hydroxide solution treatment for 2, 5 and 8 h at 35 °C. Change in chemical composition of the alkali treated fibres in comparison to that of the untreated fibres was evaluated. Fibres were characterized with respect to its FTIR, linear density, crystallinity, tenacity, modulus and % breaking strain. Tenacity of the fibres increased initially and then decreased as the time of alkali treatment was increased. Modulus of elasticity of the fibres increased with increase in alkali treatment time. Fibres lost breaking strain (%) gradually with increase in treatment time. Variation in mechanical properties of composites was studied with respect to the duration time of alkali treatment of fibres. The failure mode was particularly investigated before and after treatment for better understanding of the effect of alkali treatment. 相似文献
13.
This paper presents the results of a current study on polypropylene matrix composites processed by injection, with two different glass fiber lengths and five different volume fractions. Physical and mechanical properties were obtained, namely flexural strength, stiffness modulus and fracture toughness. The mechanical properties of the composites increased significantly with the increase of the fibers volume fraction in agreement with the Counto model. The effect of water immersion time was also analysed. Immersion in water promotes a marked decrease in mechanical properties in the early seven-ten days, and afterwards tends to stabilize. Water causes a decrease of the relative strength which increases with fiber volume fraction and reaches about 29 % and 32 % for 20 % of 4.5 mm fiber length and for 25 % of 12 mm fiber length respectively, after 28 days immersion in water. Fracture toughness increases with fiber volume fraction and is always higher for 12 mm fiber length composites than for 4.5 mm fiber length composites. 相似文献
14.
Mohammad Farsi 《Fibers and Polymers》2012,13(4):515-521
The objective of this investigation was to evaluate the mechanical, thermal stability and viscoelastic behaviors of experimental
PP composites made from wheat straw and PP-g-MA coupling agent. Four levels of wheat straw, 10, 20, 25 and 30 wt % and two
levels of coupling agent, 0 and 3 % wt were mixed with PP in rotary type mixer and injection molding process, respectively.
Tensile characteristics and impact strength, thermal gravity and dynamic mechanical and thermal analysis of the samples were
evaluated. Based on the results, it was observed that the tensile properties increased and impact strength decreased with
the increase in the fiber loading from 10 % to 30 %. Further, the composites treated with PP-g-MA exhibited improved mechanical
properties which confirmed efficient fiber-matrix adhesion. DMT analysis showed that the PP composites made of 30 % wheat
straw containing 3 % PP-g-MA showed the highest E’ and lowest tan δ than the untreated ones. Also, the thermal stability of
wheat straw was lower than PP and as filler content in the composites increased, the thermal stability decreased and the ash
content increased. 相似文献
15.
A series of the long glass fiber reinforced thermoplastic polyurethane elastomers and poly (styrene-acrylonitrile) (LGF/TPU/SAN) composites with different contents of long glass fiber were prepared by using self-designed impregnation device. Dynamic mechanical properties of TPU/SAN matrix reinforced with 10, 20 and 30 % by weight long glass fibers have been investigated by using dynamic mechanical thermal analysis (DMA). The results indicated that the content of long glass fiber and scanning frequency had some influence on dynamic mechanical properties and glass transition of LGF/TPU/SAN composites. In addition, the Arrhenius relationship has been used to calculate the activation energy of a-transition of the LGF/TPU/SAN composites. SEM demonstrates the relatively good dispersion of the long glass fiber in the TPU/SAN matrix. In addition, Effects of the content of long glass fiber on mechanical properties of the LGF/TPU/SAN composites are investigated. 相似文献
16.
Zhiling Wang Enju Wang Shuxiang Zhang Zheng Wang Yiping Ren 《Industrial Crops and Products》2009,29(1):133-138
Maleated graft polyolefins as cross-linking agents (CAs) are widely used to improve properties of wood thermoplastic composites made by melt extrusion process. In this study, novel CAs, free isocyanate group (NCO)-terminated urethane pre-polymers (UPs) were synthesized and used in manufacturing wheat straw (WS)/recycled polyethylene (PE) composites. The composites using polymeric diphenylmethane diisocyanate (pMDI) as a CA were also made in comparison. The relationship between composite properties and the level of CA and its content as well as the composite density and hot pressing time were investigated based on wood based board processes. The results show that the internal bonding (IB) strength, the IB after soaked in boiling water for 2 h (2hWIB), the modulus of rupture (MOR), the modulus of elasticity (MOE) and the 24 h thickness of swell after absorption of water (24hTS) of the composites are significantly improved with increased CA contents and composite densities. The optimal hot pressing time is 1.1 min/mm at 180°C. The cross-linking function is attributed to the reaction between free NCOs of CA molecules with hydroxyls of WS and the moisture in the raw materials, as well as the interaction between weak polar chain segments in the CA molecules to the non-polar PE. It is highly feasible to manufacture high quality composite using WS and recycled PE as raw materials when cross-linked with just 2.5% of UPs. 相似文献
17.
Ni-coated short carbon fibers (Ni-SCFs) were prepared using an electrodeposition method. Short carbon fiber (SCF) reinforced epoxy composites were prepared by changing the fiber content (0.1–0.7 wt%). To investigate the effect of Ni-coated short carbon fibers on the mechanical and electrical properties of the composites, we prepared two kinds of reinforcements: the short carbon fibers treated by 400 °C (400 °C treated SCFs) and Ni-SCFs. Fracture characteristics of the composites revealed the Ni coatings and the epoxy matrix had a better interface, so that the results of tensile and bending strength were better in epoxy/Ni-SCFs composites than those in epoxy/400 °C treated SCFs composites. The 400 °C treated SCFs decreased the electrical resistivity of the epoxy composites, compared to the pure epoxy. However the epoxy/Ni-SCFs composites had lower electrical resistivity than epoxy/400 °C treated SCFs with the same fiber content. 相似文献
18.
In recent years, composites based on glass fiber reinforced polymer have been widely used in order to meet increasing durability and safety regulations, particularly in the power cable, automotive and plane industry. In this paper, mechanical and electrical properties of high density polyethylene (HDPE) and HDPE containing glass fiber polymer composites were investigated and compared at different temperatures. Composite materials were prepared with the hot pressing method. Tensile strength, % elongation and the modulus of elasticity (or Young’s modulus) were determined for each sample at different temperatures. In addition to this, at different temperatures τ σ and τ E have mechanical and electrical lifetime respectively, corresponding to mechanical tension (σ) and electrical strength (E), and this was investigated for each sample. As compared to the mechanical and electrical properties of neat HDPE, HDPE/0.5 % glass fiber composites have been found to have better mechanical and electrical durability. 相似文献
19.
20.
Ting-Ting Li Rui Wang Ching-Wen Lou Jan-Yi Lin Jia-Horng Lin 《Fibers and Polymers》2014,15(2):315-321
Effects of needle-punching and thermo-bonding on tensile property, air permeability, puncture resistances and EMI shielding effectiveness were discussed for carbon-reinforced composite and glass-reinforced composite. The result shows that, needle-punching significantly improves static and dynamic puncture resistances. As increase of needle-punched density, static and dynamic puncture resistances show firstly increasing and then decreasing trend. Thermo-bonding almost has no influence on static puncture resistance, but effectively decreases dynamic puncture resistance. Comparatively, carbon-reinforced composite shows higher static and dynamic puncture resistances than glass-reinforced composites when being needle-punched at 200 needles/cm2. Meanwhile, carbon-reinforced composite has superior EMI shielding effectiveness to 40–60 dB at frequency of above 1 GHz, reaching 99.99 % shielding efficacy. 相似文献