共查询到19条相似文献,搜索用时 988 毫秒
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环氧树脂(EP)固化后交联密度高,呈三维网状结构,存在质脆、耐热性和耐冲击性较差等缺陷,从而限制了其应用范围。通过在环氧树脂中添加纳米Si O2,可以起到增强、增韧和提高热稳定性的作用。本文采用物理共混方法浇铸成型制备纳米Si O2/EP复合材料,并用偶联剂KH-550对纳米Si O2进行表面改性。主要研究纳米Si O2粒子的表面处理、分散方法和粒子添加量对纳米Si O2/EP复合材料力学性能的影响。结果表明:纳米Si O2的加入可以提高Si O2/EP复合材料的力学性能,其中采用偶联剂处理与超声波分散结合时纳米Si O2在环氧树脂基体中的分散效果最佳,当纳米Si O2粒子添加量为3%时,复合材料的的综合性能最佳。 相似文献
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采用浇铸成型法制备碳化硅/环氧树脂(SiC/EP)导热复合材料,研究了SiC种类、粒径、用量和表面改性方法对SiC/EP复合材料的导热性能、力学性能和热性能等影响。结果表明:SiC/EP复合材料的导热系数随纳米级SiC用量增加而增大,当φ(纳米级SiC)=17.80%时,导热系数为0.954 6 W/(m.K);SiC/EP复合材料的弯曲强度和冲击强度随纳米级SiC用量增加均呈先升后降态势,当φ(纳米级SiC)=3.50%时,两者均达到最大值。SiC经表面改性后可有效提高复合材料的导热性能和力学性能,并且改性SiC的加入可有效降低EP的玻璃化转变温度。 相似文献
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采用扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)仪和NOL环等方法,对纳米TiO2在环氧树脂(EP)体系中的分散效果、炭纤维表面状态及复合材料性能等进行了系统研究。结果表明:采用高速剪切与超声波复合分散工艺,可以将纳米TiO2均匀分散在EP体系中;当w(纳米TiO2)=2%~3%时,纳米TiO2/EP浇铸体的最大拉伸强度为112 MPa、最大弯曲强度为175 MPa和最大Tg为141.9℃;纳米TiO2可以有效改善炭纤维与EP基体间的界面结合力,形成较理想的界面相,制成的复合材料具有优异的力学性能,其拉伸强度、拉伸模量和剪切强度分别为2.15 GPa、117 GPa和49.9 MPa。 相似文献
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纳米二氧化硅水性浆料的研制 总被引:4,自引:0,他引:4
通过分散剂表面改性的方法.应用高速机械搅拌,高剪切砂磨和超声波分散等多种分散手段.制备了亲水型和疏水型两种类型纳米SiO2的水性浆料,通过常温沉降实验、Zeta电位测试以及透射电镜观察.研究了分散剂类型,用量、润湿剂类型.pH值、水性树脂和分散手段等多种因素对纳米SiO2水性浆料分散稳定性的影响。在最佳分散剂.润湿剂、pH值和加入水性树脂的条件下.通过砂磨和超声波分散相结合的手段.制得了分散稳定性良好的纳米SiO2水性浆料。 相似文献
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主要研究了分散剂、pH、颗粒级配等因素对SiC水基浆料流变性能的影响,并分析了其原因。结果表明,各分散剂对SiC浆料粘度影响效果的大小顺序依次为:四甲基氢氧化铵(TMAH)>六偏磷酸钠(SHMP)>聚乙二醇(PEG)。TMAH、SHMP、PEG三种分散剂的最佳用量分别为0.8wt.%、0.6wt.%、1.0wt.%,最佳pH为13,最佳颗粒级配(F220/F1200,下同)为1.5,当固相体积分数超过50%后SiC浆料的粘度急剧增加。通过优化工艺参数,制备出了流动性较好,固相体积分数为50%、粘度为500mPa.s的SiC陶瓷浆料。 相似文献
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研制了一种纳米TiO2水性浆料。研究了钛酸酯偶联剂、分散剂、pH、有机膨润土以及分散方法对浆料稳定性的影响。获得了最佳配方:0.12%钛酸酯偶联剂B,0.5%分散剂3275,pH=11,0.5%有机膨润土,分散方法为高速剪切30min 砂磨10h 超声波分散30min。获得了稳定性可达到3个月以上的水性纳米TiO2浆料。紫外加速老化试验表明,当纳米TiO2浆料占清漆的3%时,经过1000h的加速老化实验后,清漆不变色。 相似文献
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Xingbang Li He Zhong Jingxian Zhang Yusen Duan Hainan Bai Jingjing Li Dongliang Jiang 《International Journal of Applied Ceramic Technology》2020,17(1):239-247
Stereolithography is an attractive technique for the fabrication of complex-shaped ceramic components with high dimensional accuracy. One of the challenges in this technology is the development of high solid loading, low viscosity photosensitive ceramic suspension. In this study, the dispersion of zirconia in photocurable resin and the slurry properties were intensively investigated. Rheological measurements showed that DISPERBYK-103 proved to be an effective dispersant. 42 vol% ZrO2 suspension was successfully prepared using 3.5 wt% DISPERBYK-103 as the dispersant, with a suitable viscosity (4.88 Pa·s) below the maximum allowable viscosity value (5 Pa·s) for stereolithography applications. The adsorption behavior of DISPERBYK-103 on the surface of zirconia powders was characterized by TG and FT-IR, confirming the dispersion effect of dispersant. Contact angle measurements were also conducted to show that the adsorption of DISPERBYK-103 could help to improve the wettability between powder and photocurable resin. Results showed that DISPERBYK-103 was effective for the preparation of suitable slurries for the development of ZrO2 ceramics through stereolithography. 相似文献
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Jingxian Zhang Mikio Iwasa Dongliang Jiang 《Journal of the American Ceramic Society》2005,88(4):1013-1016
It has been well accepted that polyethylene imine (PEI) is an effective dispersant for silicon carbide (SiC) in aqueous media. However, after the addition of sintering additives (Al2 O3 and Y2 O3 ), this dispersing effect is reduced significantly. In this work, a second dispersant, citric acid, was used to resolve this problem. It was found that citric acid could decrease the slurry viscosity (without sintering additives) and enhance the PEI adsorption on SiC particle surface. The optimal amount of citric acid required to achieve a minimum viscosity for 55 vol% SiC suspensions was equal to ∼0.87 wt% (at pH ∼6.8). With the aid of citric acid, well-stabilized SiC suspensions (containing sintering additives) were realized, which exhibited slight shear thinning rheologies. After tape casting and SPS sintering, dense SiC samples were obtained with a homogeneous fine-crystalline microstructure. Results showed that citric acid was an effective dispersant for improving the dispersion of SiC particles containing sintering additives. 相似文献
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Dispersion and densification of nano Si–(Al)–C powder with amorphous/nanocrystalline bimodal microstructure 下载免费PDF全文
The dispersion behavior and densification of nano Si–(Al)–C powder with amorphous/nanocrystalline bimodal microstructure were investigated. The Si–C powders synthesized by a mechanical alloying (MA) process had a near‐spherical shape with an average particle size of 170 nm. A solid loading of 62 vol% was achieved using polyethyleneimine (PEI) as a dispersant. The optimum dispersant amount was 1 wt% based on zeta potential, sedimentation, and viscosity analysis data. The high zeta potential value (73 mV) compared with that of the commercially available SiC (65 mV) was caused by modified surface properties and consequent promotion of the cationic dispersant adsorption. A Si–Al–C slurry containing 6.5 wt% of sintering additives with a solid loading of 60 vol% was also prepared. The relative density of the dried Si–Al–C slurry was 63.3% without additional compaction, which could be densified at 1650°C at a pressure of 20 MPa using a spark plasma sintering furnace. 相似文献
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分散剂用量对碳化硅浆料流变性能的影响 总被引:13,自引:3,他引:10
使用四甲基氢氧化铵(TMAH)作为分散剂,研究了分散剂用量对SiC浆料流变性能的影响,并分析了其原因。结果表明:TMAH能够显著提高SiC粉体的zeta电位,降低浆料粘度,从而显著优化浆料的流变性能。在pH为10左右,加入质量分数为0.3%和o.6%NTMAH后zeta电位分别提高了11.7mV和21mV。实验中,在不同体积分数SiC浆料中,加入0.6%TMAH时能够达到最优性能,浆料粘度都达到最低。过量的分散剂则会增加浆料中的离子浓度而导致双电层厚度减小,从而恶化浆料的流变性。 相似文献
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围绕陶瓷粉体在光敏树脂中的分散,研究了粉体性质、分散剂种类及其掺加量、固含量对光固化ZrO2陶瓷料浆流变性能的影响。结果表明:粉体性质对料浆的流变性能有着显著影响,比表面积小、球形度高的ZrO2陶瓷粉体更有利于配制低粘度、高固含量的料浆;料浆的流变性能以及稳定性主要受分散剂种类及其掺加量的控制,以相对粉体质量4%的X-100分散剂制备的陶瓷料浆的流变性及稳定性更佳;固含量与粘度之间的关系满足Krieger-Dougherty模型。本文对分散剂的作用机理进行了分析探讨,为光固化ZrO2陶瓷料浆高精度固化成型提供了试验基础。 相似文献