共查询到20条相似文献,搜索用时 31 毫秒
1.
Chou Yong Tan Ramesh Singh Yee Ching Teh Yoke Meng Tan Boon Kar Yap 《International Journal of Applied Ceramic Technology》2015,12(2):437-442
In this work, the sinterability of forsterite powder synthesized via solid‐state reaction was investigated. X‐ray diffraction (XRD) analyses indicate that the synthesized powder possessed peaks that correspond to stoichiometric forsterite. Scanning electron micrographs revealed that the powders were formed agglomerates, which were made up of loosely packed fine particles. Subsequently, the forsterite powders were cold isostatically pressed into a disk shape under 200 MPa and sintered in air at temperature ranging from 1200°C to 1500°C (interval of 50°C) with ramp rate of 10°C/min and dwelling time of 2 h. The sinterability of each sintered samples was examined in terms of phase stability, relative density, Vickers hardness, fracture toughness, and microstructural examination. XRD examination on all the sintered samples exhibited pure forsterite, in which the generated peaks were found to be in a good agreement with JCPDS card no. 34‐0189. The densification of forsterite progressed to reach a maximum relative density of ~91% at 1500°C. This study also revealed that high‐strength forsterite ceramic can be synthesized via solid‐state reaction as forsterite attained favorable mechanical properties, having fracture toughness of 4.88 MPam1/2 and hardness of 7.11 GPa at 1400°C. 相似文献
2.
Sourav Ghosh Kartick P. Dey Milan K. Naskar 《Journal of the American Ceramic Society》2013,96(1):28-31
Nanofiber‐like mesoporous γ‐Al2O3 was synthesized using freshly prepared boehmite sol in the presence of triblock copolymer, P123 following evaporation‐induced self‐assembly (EISA) process followed by calcinations at 400°C–1000°C. The samples were characterized by thermogravimetry (TG), differential thermal analysis (DTA), X‐ray diffraction (XRD), N2 adsorption–desorption, and transmission electron microscopy (TEM). The adsorption efficiency of the samples with Congo red (CR) was studied by UV – vis spectroscopy. XRD results showed boehmite phase in the as‐prepared sample while γ‐Al2O3 phase obtained at 400°C was stable up to 900°C, a little transformation of θ‐Al2O3 resulted at 1000°C. The Brunauer‐Emmett‐Teller surface area of the 400°C‐treated sample was found to be 175.5 m2g ? 1. The TEM micrograph showed nanofiber‐like morphology of γ‐Al2O3. The 400°C‐treated sample showed about 100% CR adsorption within 60 min. 相似文献
3.
Abd El‐Aziz A Said Mohamed M M Abd El‐Wahab Alian Mohamed Alian 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2007,82(6):513-523
Different ratios of phosphotungestic acid supported on silica gel were prepared by an impregnation method with PWA loadings ranging from 1 to 30% w/w and calcined at 350 and 500 °C for 4 h in a static air atmosphere. The catalysts were characterized by thermogravimety (TG), differential thermal analysis (DTA), X‐ray diffraction, FT‐IR spectroscopy and N2 adsorption measurements. The surface acidity and basicity of the catalyst were investigated by the dehydration–dehydrogenation of isopropanol and the adsorption of pyridine (PY) and 2,6‐dimethyl pyridine (DMPY). The gas‐phase estrification of acetic acid with ethanol was carried out at 185 °C in a conventional fixed‐bed reactor at 1 atm using air as carrier gas. The results clearly revealed that the catalyst containing 10% w/w PWA/SiO2 is the most active and delivers reaction selectively to ester with 85% yield. The Brønsted acid site resulting from hydroxylation of tungsten oxide plays the main role in the formation of ester. Copyright © 2007 Society of Chemical Industry 相似文献
4.
The subsolidus phase relationship in the CaO–CuO–TiO2 ternary system at 950°C in air was investigated. Total 26 samples having various nominal compositions were prepared by the solid‐state reaction at 950°C in air, and their equilibrium phases were analyzed by powder X‐ray diffraction (XRD). The CaCu3Ti4O12 phase exhibits variable stoichiometry and forms as the Ca1?xCu3+xTi4O12‐type (?0.019 ≤x ≤0.048) solid solution at 950°C in air. On the basis of our results and previous reports on the binary phase diagrams, the subsolidus phase diagram of the CaO–CuO–TiO2 ternary system could be constructed at 950°C in air. 相似文献
5.
Marioara Nechifor 《应用聚合物科学杂志》2010,116(3):1450-1458
A novel monomer diacid, 6,6′‐methylenebis(2‐oxo‐2H‐chromene‐3‐carboxylic acid), was synthesized and used in a direct polycondensation reaction with various aromatic diamines in N‐methyl‐2‐pyrrolidone solution containing dissolved LiCl and CaCl2, using triphenyl phosphite and pyridine as condensing agents to give a series of novel heteroaromatic polyamides containing photosensitive coumarin groups in the main chain. Polyamide properties were investigated by DSC, TGA, GPC, wide‐angle X‐ray scattering, viscosity, and solubility measurements. The copolymers were soluble in aprotic polar solvents, and their inherent viscosities varied between 0.49 and 0.78 dL g?1. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 27,500–43,900 g mol?1 and 46,500–66,300 g mol?1, respectively, and polydispersities in the range of 1.48–1.69. The aromatic polyamides showed glass‐transition temperatures (Tg) ranging from 283 to 329°C and good thermal properties evidenced by no significant weight loss up to 380°C and 10% weight loss recorded above 425°C in air. All the polyamides exhibited an amorphous nature as evidenced by wide‐angle X‐ray diffraction and demonstrated a film forming capability. Water uptake values up to 3.35% were observed at 65% relative humidity. These polymers exhibited strong UV‐vis absorption maxima at 357–369 nm in DMSO solution, and no discernible photoluminescence maxima were detected by exciting with 365 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
6.
Tengyang Zhu Xing Yang Yayun Zheng Xiaoqi He Feifei Chen Jujie Luo 《Polymer Engineering and Science》2019,59(Z1):E14-E23
A series of poly(amide‐co‐poly(propylene glycol)) (PA‐PPG) random copolymers with different content of PPG were designed by polycondensation reaction. These random copolymers were blended up to 60% with commercially available Pebax 2533. The blend membranes were characterized by Fourier‐transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscope (SEM). Gas permeation properties of these blend membranes were investigated using five single‐gases (CO2, H2, O2, CH4, and N2) at different temperature of 25–55°C and 1.0 atm. The impacts of content of PA‐PPG with different PPG content and operating temperature on CO2 separation properties of Pebax/PA‐PPG blend membranes were studied. The results showed that CO2 permeability gradually increased with the increasing operating temperature, whereas CO2 permeability gradually decreased with the increase in content of PA‐PPG. CO2/N2 selectivity gradually increased with the increase in content of PA‐PPG. In particular, Pebax/PA‐PPG (50)–60% displayed excellent CO2 and O2 separation properties (PCO2 = 79.7 Barrer and PO2 = 13.6 Barrer, CO2/N2 = 34.7 and O2/N2 = 5.9) at 25°C and 1.0 atm. POLYM. ENG. SCI., 59:E14–E23, 2019. © 2018 Society of Plastics Engineers 相似文献
7.
Jianfeng Wu Meng Liu Xiaohong Xu Yaxiang Zhang Xinbin Lao 《International Journal of Applied Ceramic Technology》2014,11(2):246-253
Si3N4–SiC composite ceramics used for volumetric receivers were fabricated by pressureless sintering of micrometer SiC, Si3N4, andalusite, and other minor additions powders. Mechanical, thermal expansion, thermal conductivity, and thermal shock resistance properties were tested at different sintering temperatures. The best sintering temperature of optimum formula A2 is 1360°C, and the bending strength reaches 79.60 Mpa. And moreover, its thermal expansion coefficient is 6.401 × 10?6/°C, thermal conductivity is 7.83 W/(m K), and no crack occurs even subjected to 30 cycles thermal shock with a bending strength increase rate of 4.72%. X‐ray diffraction results show that the phase constituents of the sintered products mainly consist of SiC, Si3N4, mullite, and quartz. Microstructure that is most appropriate and exhibits maximal thermal shock resistance was detected using SEM. The porosity of Si3N4–SiC ceramic foam prepared from formula A2 is 95%, which provides a rapid and steady action for the receiver. The evaluation of the present foam shows that Si3N4–SiC ceramic composite is a good candidate for volumetric receivers. 相似文献
8.
Structural evaluation and mechanical property of boron nitride fibers during melt‐drawn fabrication process
下载免费PDF全文
![点击此处可从《International Journal of Applied Ceramic Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chonghai Wang Changqing Hong Liwen Yan Xue Lin Mingxia Zhang Jiazhi Wang Qiang Qu 《International Journal of Applied Ceramic Technology》2018,15(3):660-667
Boron nitride (BN) fibers were fabricated on a large scale through the melt‐drawn technique from low‐cost boric acid, NH3, and N2. Evolution of structure and properties of BN fibers during the fabrication process was studied by Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), and X‐ray photoelectron spectroscopy (XPS). The mechanical properties of BN fibers were tested and analyzed. The results shown that both the mechanical properties and the crystallinity of BN fibers slightly increased with the temperature from 450 to 850°C, due to the combination of the fused‐B3N3. For BN fibers heat‐treated at 850 or 1000°C, the tensile strength (σR) and elastic modulus (E) were strongly increased because of the increase in crystallization of the BN phase. The meso‐hexagonal BN fibers with a diameter of 5.0 μm were fabricated at 1750°C, of which the tensile strength (σR) and elastic modulus (E) are 1200 MPa and 85 GPa, respectively. BN fibers with excellent mechanical properties and proper diameters were obtained by nitriding of green fibers during their conversion into ceramic. 相似文献
9.
Jing Luo Zongbo Zhang Wei Liu Xiujun Wang Zhijian Peng Yongming Luo Caihong Xu 《应用聚合物科学杂志》2012,126(3):853-859
A polymeric precursor, polysiloxazane (PSON), for SiCON ceramics has been synthesized by the partial hydrolysis of MeViSiCl2, MeHSiCl2, and MeSiCl3 followed by ammonolysis reaction of the hydrolyzed intermediates with NH3. The structure and thermal properties of the polymeric precursor were investigated by means of Fourier transfer infrared spectra (FTIR), 1H‐NMR, 29Si‐NMR, gel permeation chromatography, and thermogravimetric analysis. The structure of the SiCON ceramics derived from the pyrolysis of PSON was characterized by FTIR and X‐ray diffraction. The as‐synthesized PSON produced mainly α‐Si3N4 crystalline phase during pyrolysis at 1500°C under N2 atmosphere, whereas when pyrolyzed at 1500°C under Ar atmosphere, crystalline phases of α/β‐SiC and/or α‐Si3N4 were detected. © 2012 Wiley Periodicals, Inc. J fAppl Polym Sci, 2012 相似文献
10.
Esther García‐Tuñon Jaime Franco Salvador Eslava Vineet Bhakhri Eduardo Saiz Finn Giuliani Francisco Guitián 《Journal of the American Ceramic Society》2013,96(3):759-765
Millimeter‐sized hydroxyapatite (HA) single crystals were synthesized from chlorapatite (ClAp) crystals via the ionic exchange of Cl? for OH? at high temperature. X‐ray diffraction, Fourier‐transform infrared spectroscopy, and chloride content measurements were used to follow the progress of this conversion, and to assess the effect of the experimental conditions (temperature, time, and atmosphere). Cl?→OH? exchange took place homogeneously and was enhanced by firing in wet air. After firing at 1425°C for 2 h 92% of the Cl? ions were exchanged by OH? while maintaining crystal integrity. Temperatures above 1450°C damaged the surface of the crystals, destroying the hexagonal habit at 1500°C. The composition of these apatite crystals was close to bone mineral content. Their nanoindentation hardness (8.7 ± 1.0 GPa) and elastic nanoindentation modulus (120 ± 10 GPa) were similar to those of the starting ClAp (6.6 ± 1.5 GPa, and 110 ± 15 GPa, respectively). However, their average flexural strength was ~25% lower due to the formation of defects during the thermal treatments. 相似文献
11.
Soluble and crosslinkable poly(phthalazinone ether ketone)s with pendent terminal ethynyl groups: synthesis,characterization and click modification
下载免费PDF全文
![点击此处可从《Polymer International》网站下载免费的PDF全文](/ch/ext_images/free.gif)
New poly(phthalazinone ether ketone)s (PPEKs) with pendent terminal ethynyl groups were synthesized by the aromatic nucleophilic substitution (SNAr) polycondensation reaction of a new bisphenol monomer, 2‐(3‐ethynylphenyl)hydroquinone, with 4‐(4′‐hydroxyphenyl)phthalazin‐1(2H)‐one and 4,4′‐bis(4‐fluorophenyl) ketone, followed by click modification reaction with 1‐azidopyrene. Fourier transform infrared and NMR spectral data of the model compound indicated that the terminal ethynyl groups were stable in SNAr reaction conditions, thus allowing the synthesis of the desired polymers. The PPEKs obtained with glass transition temperature (Tg) in the range 152–245 °C were amorphous, characterized by wide‐angle X‐ray diffraction, and dissolved in organic solvent to cast into transparent and flexible films. Differential scanning calorimetry results indicated that the curing reaction of the terminal ethynyl groups of the copolymers took place upon heating to 250 °C. The Tg of cured PPEKs was increased to about 260 °C. They also exhibited excellent thermal stability with 5% weight loss temperatures ranging from 448 to 527 °C in various atmospheres. The PPEKs with pendent terminal ethynyl groups were subsequently functionalized with pyrene through click reaction. A dilute chloroform solution displayed a red‐shifted emission profile. © 2014 Society of Chemical Industry 相似文献
12.
Synthesis and growth mechanism of single crystal β‐Si3N4 particles with a quasi‐spherical morphology
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Si‐Yuan Sun Yi‐Yao Ge Qi Wang Zhao‐Bo Tian Jie Zhang Wei Cui Guang‐hua Liu Ke‐Xin Chen 《Journal of the American Ceramic Society》2018,101(10):4526-4537
Single‐crystal β‐Si3N4 particles with a quasi‐spherical morphology were synthesized via an efficient carbothermal reduction‐nitridation (CRN) strategy. The β‐Si3N4 particles synthesized under an N2 pressure of 0.3 MPa, at 1450°C and with 10 mol% unique CaF2 additives showed good dispersity and an average size of about 650 nm. X‐ray photoelectron spectroscopy analysis revealed that there was no SiC or Si–C–N compounds in the β‐Si3N4 products. Selected‐area electron‐diffraction pattern and high‐resolution image indicated single crystalline structure of the typical β‐Si3N4 particles without an obvious amorphous oxidation layer on the surface. The growth mechanism of the quasi‐spherical β‐Si3N4 particles was proposed based on the transmission electron microscopy and energy dispersive X‐ray spectroscopy characterization, which was helpful for controllable synthesis of β‐Si3N4 particles by CRN method. Owing to the quasi‐spherical morphology, good dispersity, high purity, and single‐crystal structure, the submicro‐sized β‐Si3N4 particles were promising fillers for preparing resin‐based composites with high thermal conductivity. 相似文献
13.
Norihiro Takamura Lisa Viculis Chunxin Zhang Richard M Laine 《Polymer International》2007,56(11):1378-1391
The reaction of 4‐vinyl‐1‐cylcohexene with [HMe2SiOSiO1.5]8 provides tetra‐ and octa‐2‐cyclohexenylethyloctasilsesquioxanes. The tetrabifunctional [cyclohexenylethylMe2SiOSiO1.5]4‐[HMe2SiOSiO1.5]4 (average degree of functionalization) melts near 80 °C and can be cast and then cured (by thermal hydrosilylation) into transparent nanocomposite shapes. These materials, while not nanoporous, offer dielectric constants of 2.8–2.9 at 100 kHz to 3 MHz, and are air stable to temperatures ≥ 400 °C. The resulting materials appear (by X‐ray diffraction) to be partially ordered after curing. The octafunctional material also melts at low temperatures (ca 120 °C) and can be copolymerized with hydridosiloxanes to give similar materials with lower thermal stability. The synthesis and characterization of the starting materials is described, as well as thermal curing studies and properties characterization of the resultant nanocomposites. Copyright © 2007 Society of Chemical Industry 相似文献
14.
A series of novel polyimides was prepared from various diamines (with bisphenol units) and various aromatic tetracarboxylic dianhydrides via a two‐step (thermal imidization) method. The monomers and polymers were produced in high yields. The benzophenone series exhibited better solubility than the pyromellitic series and, especially, those with the alkyl (methyl)‐substituted ring exhibited good solubility and could be readily dissolved in polar aprotic solvents such as dimethylformamide and N,N′dimethylacetamide. The glass transition temperatures of all polyimides were found to be 235–322 and 223–332°C, respectively, by DSC and dynamic mechanical analysis. Thermogravimetric analyses indicated that the polymers were fairly stable up to 482–617°C (10 wt % loss in N2) and 480–610°C (10 wt % loss in air). Wide‐angle X‐ray diffractograms revealed that most polyimides were predominantly amorphous. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 945–952, 2003 相似文献
15.
Fengdong Qu Caihui Feng Chao Li Wei Li Shanpeng Wen Shengping Ruan Haifeng Zhang 《International Journal of Applied Ceramic Technology》2014,11(4):619-625
Co3O4 nanofibers were prepared by an electrospinning method and characterized by differential thermal and thermal gravimetric analyzer (DTA‐TGA), X‐ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FT‐IR), and scanning electron microscopy (SEM). Xylene‐sensing properties of the as‐prepared nanofibers were also investigated in detail. The results showed that the morphology of the as‐prepared fibers was largely influenced by the calcination temperature. The Co3O4 nanofibers calcined at 500°C exhibited the highest response to xylene in a wide concentration range. Moreover, Co3O4 nanofibers calcined at 500°C also exhibited good selectivity, fast response (15 s) and recovery (22 s) rate at a low operating temperatures of 255°C. These properties make the fabricated nanofibers good candidates for xylene detection. 相似文献
16.
Taihang Li Jingling Yan Huili Yang Dongfeng Li Zhen Wang Mengxian Ding 《应用聚合物科学杂志》2009,114(2):1226-1234
A novel diamine, 1,4‐bis [3‐oxy‐(N‐aminophthalimide)] benzene (BOAPIB), was synthesized from 1,4‐bis [3‐oxy‐(N‐phenylphthalimide)] benzene and hydrazine. Its structure was determined via IR, 1H NMR, and elemental analysis. A series of five‐member ring, hydrazine‐based polyimides were prepared from this diamine and various aromatic dianhydrides via one‐step polycondensation in p‐chlorophenol. The inherent viscosities of these polyimides were in the range of 0.17–0.61 dL/g. These polymers were soluble in polar aprotic solvents and phenols at room temperature. Thermogravimetric analysis (TGA) showed that the 5% weight‐loss temperatures of the polyimides were near 450°C in air and 500°C in nitrogen. Dynamic mechanical thermal analysis (DMTA) indicated that the glass‐transition temperatures (Tgs) of these polymers were in the range of 265–360°C. The wide‐angle X‐ray diffraction showed that all the polyimides were amorphous. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
17.
Moisés Frias Raquel V. de la Villa Rosario García María I. Sánchez de Rojas Trino A. Baloa 《Journal of the American Ceramic Society》2013,96(10):3188-3195
This study reports on exhaustive scientific research into the influence of the activation temperature of inert waste from drinking water treatment plants for use as supplementary cementing material in cements. The effect of activation temperature on the mineralogy of the reactive products resulting from pozzolanic activity and on the evolution of the hydrated phases formed during the pozzolanic reaction at 28 d of curing was analyzed with the assistance of different instrumental techniques such as X‐ray fluorescence, X‐ray diffraction, thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopy. The results show that all the activated products (based on metakaolinite) presented high pozzolanic activity at all ages of the reaction (up to 90 d), although 600°C at 2 h are the recommended ideal activation conditions from an energetic and economic viewpoint. The activation temperature (600°C–900°C for 2 h of retention) plays an important role in the reaction kinetics in activated drinking water waste/Ca(OH)2 systems. The hydrated phases identified under these activation conditions were very similar, but with important differences in the crystalline aluminates phases content. Thus, the formation of stratlingite (C2ASH8) is favored at low temperatures (<800°C); whereas at higher temperatures (at 900°C), tetra calcium aluminate hydrate (C4AH13) appears as the only crystalline phase. Finally, this type of treatment of drinking water waste (based on kaolinite) is ideal to obtain future pozzolans based on recycled metakaoline, a product that is currently listed in international standards for the manufacture of commercial cements. 相似文献
18.
Kevin C. Seymour Robert W. Hughes Waltraud M. Kriven 《Journal of the American Ceramic Society》2015,98(12):4096-4101
The thermal expansion behavior of the orthorhombic phase in the Ln2TiO5 (Ln = La, Nd, Gd, Dy, and Y) system was evaluated, using synchrotron X‐ray diffraction from room temperature to approximately 1500°C in air. The components of the thermal expansion tensor were calculated from the refined d‐spacings, using the program CTEAS. Subsequent analysis of the thermal expansion and crystallographic information revealed that the mechanism behind the thermal expansion was a result of strained trigonal‐bipyramidal structures overcoming an energy barrier to become more relaxed. The temperature at which a significant shift in the trigonal‐bipyramidal structure manifests was correlated with the size of the rare‐earth cation that dictates the volume of the overall cell. Larger rare‐earth cations with larger cell volumes allow more room for the trigonal‐bipyramidal structures to easily relax. 相似文献
19.
Valeria Di Sarli Gianluca Landi Luciana Lisi Almerinda Di Benedetto 《American Institute of Chemical Engineers》2017,63(8):3442-3449
The potential of diesel particulate filters wash‐coated with highly dispersed nano‐metric ceria particles for continuous regeneration has been investigated. To this end, catalytic filters were prepared, soot‐loaded (avoiding the formation of the cake layer), and regenerated—under isothermal conditions—at temperature ranging from 200–600°C. Results have shown that catalytic oxidation of soot starts from 300°C and, at all temperatures, the selectivity to CO2 is higher than 99%. 475°C is the minimum temperature at which the filter is regenerated via catalytic path. At this temperature, the catalytic filter maintains substantially the same performance over repeated cycles of soot loading and regeneration, indicating that the thermal stability of ceria is preserved. This has been further confirmed by comparison between the outcomes obtained from characterization (X‐ray powder diffraction, N2 adsorption at 77 K, Hg intrusion porosimetry, and scanning electron microscope/energy dispersive X‐ray analysis) of fresh filter and filter subjected to repeated regeneration tests. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3442–3449, 2017 相似文献
20.
A series of silylene–acetylene preceramic polymers 3a–e were synthesized by polycondensation reaction of dilithioacetylene with dichlorosilane (H2SiCl2) or/and methyldichlorosilane (MeSiHCl2). Their structures were confirmed by infrared spectra (IR), and 1H and 29Si NMR spectroscopies. Differential scanning calorimetry (DSC) diagrams show exotherms centered at 200 to 233°C temperature range, attributed to crosslinking reaction of the acetylene and Si? H groups. After thermal treatment, the obtained thermosets 4a–e possess excellent thermal stability. Thermogravimetric analysis (TGA) under nitrogen show the Td5s (temperature of 5% weight loss) for all the thermosets are above 600°C, and the overall char yields are between 95.62% and 89.67% at 900°C. After pyrolysis at 1200°C, the obtained ceramic residues 5a–e exhibit good thermo‐oxidative stability with final weight retention between 98.76% and 91.66% at 900°C under air. In particular, perhydroploy(silylene)ethynylene 3a , which has the highest Si/C ratio in silylene–acetylene polymers, has the highest char yield, and the derived ceramic material 5a displays the best thermo‐oxidative stability. Based on Scanning electron microscopy and its associated energy‐dispersive X‐ray microanalysis (SEM EDX) and 13C magic angle spinning nuclear magnetic resonance (MAS NMR) analysis, ceramic 5a contains the highest SiC content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献