Effects of Alkylation of Silica Filler on Rubber Reinforcement

1994 ◽  
Vol 67 (5) ◽  
pp. 834-844 ◽  
Author(s):  
Yu-Chun Ou ◽  
Zhong-Zhen Yu ◽  
A. Vidal ◽  
J. B. Donnet

Abstract Rubber reinforcement of silicas with different surface alkylation have been evaluated by studies of NH3-modified swelling, swelling volume fraction, stress-strain tests, and scanning electron microscopy. Effects of silica alkylation on filler dispersion has been explained on the basis of surface energy and acid-base interactions. Bound rubber reductions have been explained according to acid-base interactions and/or physical entanglements. Hysteresis losses have been interpreted based on the reductions of polymer-filler and filler-filler interactions. The results show that the extent of reinforcement in NR and SBR vulcanizates is reduced when the silicas are alkylated, especially in the case of the hexadecyl group. However, in NBR vulcanizates the alkylation seems to have less influence on the reinforcement characteristics of the silica.

Author(s):  
Xiaochun Li ◽  
Zhiwei Li

Permalloy NiFe matrix nanocomposite layers were electroplated on a copper substrate. The volume fraction of nano-sized Si3N4 particles in NiFe matrix was controlled by the addition of various percentages of Si3N4 particles in the NiFe electrolyte. The nanocomposite layers were analyzed by a scanning electron microscopy (SEM). Microhardness test was performed. With nano-sized Si3N4 particles in the NiFe matrix, the microhardness of NiFe was improved. The samples were then annealed at 800 °C for about 20 hours. The microhardness declined more with more Si3N4 particles in the NiFe matrix. The analysis result from Energy Dispersive Spectrometer (EDS) in the SEM showed that the hardness declination could be caused by the segregation of Si3N4 in the NiFe matrix. Finally this paper presents nanocomposite micromolds fabricated by electroplating onto polymer molds that were fabricated by micro-stereolithgraphy.


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1002
Author(s):  
Chunping Huang ◽  
Yang Xia ◽  
Chun Xia ◽  
Fencheng Liu

A double reinforced layer on an aluminum alloy surface was produced using friction stir processing (FSP) by adding 34CrNiMo6 powder into Al (AA2024) substrate for better wear resistance and gradient transitions. The microstructures of the composites were analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The phase composition was examined by X-ray diffraction (XRD). The results show that the double reinforced layer of the Al13Fe4 intermetallic compound could be successfully fabricated via FSP. The volume fraction of Al13Fe4 in the double reinforced layer was higher than in the single reinforced layer due to adding 34CrNiMo6 powder and reinforced twice, and the Al13Fe4 particles were dispersed more homogeneously in the double reinforced layer. The interfaces between the double and single reinforced layer had a good metallurgical bond. The microhardness of the double reinforcement layer was significantly increased. Compared with the AA2024 substrate, the microhardness of the double and single reinforced layers increased five- (576 HV) and two-fold (254 HV), respectively.


2005 ◽  
Vol 498-499 ◽  
pp. 251-257 ◽  
Author(s):  
E.G. Gomes ◽  
J.L. Rossi

The material used in this work was produced by spray forming AA7475 aluminium alloy and co-depositing silicon carbide particles (20% volume fraction). The spray formed composite billets were hot extruded into round bars. The microstructure was examined in the as received and heat treated (annealed, aged, and overaged) conditions by scanning electron microscopy. Scanning electron microscopy revealed an extensive Mg2Si phase precipitation at the Al/SiCp interface due probably to Mg segregation from the matrix to the interface, during the heat treatments.


2011 ◽  
Vol 194-196 ◽  
pp. 52-55 ◽  
Author(s):  
Bao Cai Wu ◽  
Feng Shi ◽  
Xin Yu Cheng ◽  
Rui Min Lin ◽  
Chun Ming Liu

Microstructures and textures after annealing at 680°C in low carbon Al-killed steels with low finishing temperature and high coiling temperature were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and X-Ray Diffractometer (XRD). The results show that higher coiling temperature and lower finishing temperature can both cause the appearance of equiaxed grain and line cementite. The equiaxed grain in 2# steel with higher coiling temperature is the more obvious. Advantage textures are weak in the steels with higher coiling temperature and lower finishing temperature and volume fraction of {111}fiber in 2# steel with higher coiling temperature is only 7.17%, so the stamping property should be worse.


2018 ◽  
Vol 38 (5) ◽  
pp. 199-210 ◽  
Author(s):  
Xiu-Wei Yu ◽  
Hao Wang ◽  
Zhong-Wei Wang

Variation of yarn fiber volume fraction, induced by the compression between adjacent yarns during the manufacturing process of textile composites, is difficult to be determined by using a single imaging method. A method combining scanning electron microscopy and micro-computed tomography is proposed to quantify the variation of yarn fiber volume fraction of textile composites, which is decomposed into systematic trend and stochastic deviation. The method takes the advantages of high resolution of scanning electron microscopy and wide 3D view of micro-computed tomography. Average fiber cross-sectional areas are acquired by analyzing hundreds of fiber cross-sectional areas in scanning electron microscopic images. Yarn cross-sectional area is determined by fitting ellipse to the labeled yarn cross-section in slices of micro-computed tomography images. The results of E-glass/epoxy and carbon/epoxy specimens show that their systematic trends of yarn fiber volume fraction combined with standard deviations of stochastic deviation, relative to the respective global means, fluctuate between [−11.4%, 15.3%] and [−12.9%, 10.7%], respectively. Yarn FVF varies in specimen obviously and needs to be considered in mechanical property prediction.


Author(s):  
Armin Shahmohmmadi ◽  
Mostafa Baghani ◽  
Masoud Shariat Panahi ◽  
Kui Wang ◽  
Ehsan Hasanpur ◽  
...  

In this study, the corrosion behavior of biodegradable composites is modeled. These composites are made of Poly-Lactic acid and Magnesium with different volume fractions. The scanning electron microscopy images of these composites were taken, and statistical reconstruction of the composite based on scanning electron microscopy images was done by the phase recovery algorithm, the three-dimensional structure of this composite was extracted with this reconstruction, then a three-dimensional cellular automata model was developed to predict the corrosion of this composite. Results of experiments for the composite with 10% of Magnesium volume fraction were used to calibrate the parameters of the cellular automata model, and with these parameters, the results for the composite with 5% of Magnesium volume fraction was obtained, and with comparing these data with the results of the experiment, our model was validated. In the end, we estimated the mechanical properties of these composites and analyzed the results.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Omar A. Al-Hartomy ◽  
Ahmed A. Al-Ghamdi ◽  
Falleh Al-Salamy ◽  
Nikolay Dishovsky ◽  
Desislava Slavcheva ◽  
...  

In this study the influence of fullerenes in concentrations from 0.5 to 1.5 phr on both the vulcanization characteristics of the compounds and physicomechanical, dynamic, and dielectric properties and thermal aging resistance of nanocomposites on the basis of natural rubber has been investigated. The effect of the filler dispersion in the elastomeric matrix has been also investigated. Neat fullerene and the composites comprising it have been studied and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).


2019 ◽  
Vol 6 (2) ◽  
pp. 378-385
Author(s):  
Hoo Tien Nicholas Kuan ◽  
Kennedy Jadum ◽  
Mahshuri Yusof ◽  
Sim Nee Ting ◽  
Chee Khoon Ng

The mechanical properties of oxo-biodegradable high-density polyethylene (oxo-HDPE) composites reinforced betel nut husk (BNH) fibre were studied in this research. A neat oxo-HDPE laminate and four betel nut fibre reinforced oxo-HDPE composites were fabricated using hot press compression moulding method. The composites contain 7%, 12%, 17%, and 22% fibres volume fraction respectively. The cross section of the composite was observed under scanning electron microscopy (SEM) and all five laminates are put through tensile test and hardness test. The result of the study shows that adding betel nut husk (BNH) fibres as reinforcement increases its tensile strength, specific tensile strength, and hardness of the composites. The good lamination observed under scanning electron microscopy (SEM) enable good transfer and distribution of stresses from the matrix to the fibres.


Metalurgi ◽  
2017 ◽  
Vol 32 (3) ◽  
pp. 137 ◽  
Author(s):  
Rizki Syahfina ◽  
Bintoro Siswayanti ◽  
Sigit Dwi Yudanto ◽  
Agung Imaduddin ◽  
Nurul Suhada ◽  
...  

Bi1.6Pb0.4Sr2Ca2Cu3O10+δ with the addition of carbon nanotubes (CNT) and TiO2 have been synthesized using solid state reaction method with the repeated sintering process. 0.1 wt % of CNT and 5 wt% of TiO2 have been added to analyze the effect on the synthesizing of 2223 phases. The samples were analyzed using XRD (X-ray diffractometer) and SEM (Scanning Electron Microscopy). Based on the XRD results, 2223 and 2212 were formed. The addition of CNTs and TiO2 reduced the intensity of 2223 phases. This is due to the addition of CNTs and TiO2 as an impurity and prevent the formation of the phases. Also, the repeated sintering process led to the increase of 2223 phase, and the decrease of 2212 phase. However, the repeated sintering process in the B-CNT and B-TiO samples eliminates the impurities phase thus increasing the volume fraction 2223 and decreasing the volume fraction 2212. Based on morphological structure through SEM observation, the addition of CNT in the Bi(Pb)-2223 samples formed longer plates with large porosity spaces while the addition of TiO2 formed clumps on the Bi(Pb)-2223 morphological structure. However, the repeated sintering process improves the morphological structure of B-CNT and B-TiO becomes increasingly denser and the smaller porosity space.AbstrakTelah dilakukan sintesis Bi1,6Pb0,4Sr2Ca2Cu3O10+δ dengan penambahan CNT (carbon nanotube) dan penambahan TiO2 menggunakan metode reaksi padatan dengan proses sintering berulang. Penambahan CNT sebesar 0,1 %berat dan TiO2 sebesar 5 %berat dan sintering berulang dilakukan untuk mempelajari pengaruhnya terhadap pembentukan fasa 2223 beserta pengotornya, dan mempelajari perubahan morfologi Bi1,6Pb0,4Sr2Ca2Cu3O10+δ. Bi1,6Pb0,4Sr2Ca2Cu3O10+δ yang dibuat dianalisis dengan XRD (x-ray diffractometer) dan SEM (scanning electron microscopy). Berdasarkan hasil XRD, penambahan 0,1 %berat CNT dan TiO2 sebesar 5 %berat pada superkonduktor Bi(Pb)-2223 diketahui menghasilkan fasa 2223, fasa 2212, dan juga fasa pengotor. Namun proses sintering berulang mampu mengurangi fasa impuritas, meningkatkan fraksi volume 2223, serta menurunkan fraksi volume 2212.   Berdasarkan pengamatan struktur morfologi melalui SEM, penambahan CNT pada superkonduktor Bi(Pb)-2223 membentuk serpihan memanjang dengan ruang porositas yang besar sedangkan penambahan TiO2 membentuk gumpalan pada struktur morfologi Bi(Pb)-2223. Proses sintering berulang mampu memperbaiki struktur morfologi B-CNT dan B-TiO menjadi semakin rapat dan ruang porositas yang semakin kecil.  


2018 ◽  
Vol 777 ◽  
pp. 44-49
Author(s):  
Waraphorn Buakhlee ◽  
Pimsiree Suwanna ◽  
Wirunya Keawwattana

Due to the dispersion of silica and reducing filler-filler interaction, the improvement of filler-rubber interaction was enhanced the physical properties of silica/NR compounds. This research was then focused on the production of silica masterbatches with surface treatment by surfactant to enhance the silica dispersion. The silica dispersion examined by scanning electron microscopy (SEM)c and the mechanical properties of vulcanizates prepared from the masterbatches were compared with those prepared by a conventional direct mixing method. The mechanical properties of silica/NR masterbatches exhibited greater modulus, tensile strength and hardness compared to the corresponding conventional mixes. A better silica/NR interaction of silica/NR masterbatch was achieved confirming by higher the bound rubber content and lower Payne effect, leading to the greater mechanical properties.


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