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在高性能聚合物纳米复合材料的构筑中,为了实现碳纳米颗粒的精准选择,揭示碳纳米颗粒形貌对聚合物复合材料微观结构及宏观性能的影响十分必要。采用热压法制备了富勒烯、碳纳米管、石墨烯和炭黑等不同形貌碳纳米颗粒填充改性的聚乙烯复合材料,并利用正电子湮没寿命谱探讨了碳纳米颗粒形貌对复合材料自由体积特性的影响。此外,系统地研究了碳纳米颗粒形貌对聚乙烯复合材料流变、力学、电学和热学性能的影响,并将形貌对宏观性能的影响与复合材料自由体积分数的变化进行了关联。 相似文献
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《玻璃钢/复合材料》2021,(4)
高体分比颗粒增强复合材料被广泛应用于工程领域。本文通过建立该类复合材料的弹塑性细观力学模型,系统研究了该类材料在单轴拉压情况下的宏观弹塑性力学性能。在有效模量预测方面,分别采用Mori-Tanaka模型和Ju等提出的相互作用细观力学模型研究了高体分比颗粒增强复合材料的宏观有效模量,指出了Mori-Tanaka模型的局限性。针对高体分比颗粒增强复合材料弹塑性力学性能,采用Hill定理和场扰动方法建立了宏观应力与基体等效应力的关系,分别采用Mori-Tanaka模型和Ju模型研究了颗粒增强复合材料在不同体分比下的宏观弹塑性力学性能,并将理论预测与实验数据和有限元模拟结果进行了对比分析。结果表明,针对高体分比颗粒增强复合材料宏观弹塑性力学性能预测,本文方法相比传统模型结果更准确,可为工程领域中该类材料的弹塑性力学性能预测提供一定的理论参考。 相似文献
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丁永红;许晓峰;刘晶如;俞强;姚超 《中国塑料》2011,26(12):43-46
采用不同硅烷偶联剂对纳米凹凸棒土(简称纳米凹土)进行了改性,通过熔融共混法制备了聚对苯二甲酸乙二醇酯(PET)/纳米凹土复合材料,用毛细管流变仪和旋转式流变仪及扫描电子显微镜研究了PET/纳米凹土复合材料的流变特性、动态黏弹性以、动态力学性能及复合材料的微观形态。结果表明,纳米凹土的加入降低了PET的熔体黏度和玻璃化转变温度;使复合材料呈现假塑性流体特征;纳米凹土颗粒间不存在相互作用;硅烷偶联剂使纳米凹土能降低熔体的表观黏度,在PET中分散得较好。 相似文献
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本文介绍了一种以组分材料性能为基础确定SMC材料平面及交叉方向热弹性能的计算预测方法,将SMC材料模型看作对称的三层复合材料结构,因此采用经典的层板理论来探讨SMC的有效变形特征。中心层的性能用单向复合材料来表达,用Kerner-Hashin理论来预测颗粒填料复合材料的性能;对片状颗粒填料的复合材料Lewis-Nielser理论可使试验与理论数据很好符合。但体系加入低收缩添加剂对性能的影响不能仅用力学模型来说明。 相似文献
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大气污染治理水平的提高对静电除尘器的净化效率提出更高要求。利用数值模拟设计静电除尘器有助于优化结构和提高性能,而模拟过程中选用的颗粒荷电模型很大程度决定了模拟结果的准确性。通过建立双区静电除尘器电场、流场和颗粒运动模型,计算两种荷电模型下双区静电除尘器内部颗粒运动轨迹,分析荷电模型对荷电区和收尘区内颗粒轨迹的影响。通过两种荷电模型下0.4 μm颗粒和7.5 μm颗粒去除率模拟值与实测值的对比,发现荷电模型导致的模拟值差异随颗粒粒径的减小而增大。定电量模型适用于电场荷电为主的大粒径颗粒,对扩散荷电的忽略使得该模型下小粒径颗粒的模拟去除率远小于实测值。综合考虑电场荷电量和扩散荷电量随时间变化的模型可以很好地反映小粒径颗粒的荷电特性,更适用于对小粒径颗粒荷电行为特征的数值模拟。 相似文献
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仪器化冲击仪在理论研究中的作用:Ⅰ仪器简介及数据处理 总被引:1,自引:0,他引:1
介绍了仪器化冲击仪的实验装置及工作原理,仪器化冲击仪除了能给出普通冲击仪所给出的总能量外,还能记录下载荷-时间(F(t)-t)曲线及能量-时间(E(t)-t)曲线,可以得到许多有用的描写断裂行为的参数如最大载荷Fmax,裂纹起始能Ei,裂纹扩展能Ep及韧度参数DI等,同时还可以对断裂过程进行分析研究,由此说明仪器化冲击仪在理论研究中将起到很重要的作用。 相似文献
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本文介绍了XQ-1型纤维强伸度仪结构和原理,并对三种不同类型的纤维强力测试仪器的特点及测试结果进行了分析. 相似文献
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碳纤维增强PEEK复合材料的摩擦学性能研究 总被引:7,自引:0,他引:7
用磨损试验机对碳纤维增强聚醚醚酮(PEEK)复合材料进行室温干滑动磨损试验。考察了碳纤维的含量,石墨润滑剂,对靡时间及载荷对材料靡损量及摩擦系数的影响,并用电子显微镜对其磨损表面进行了观察与分析,同时对材料的磨损机理进行了探讨,研究结果表明,随着载荷的升高和对磨时间的延长,材料的摩擦系数逐渐降低并趋于稳定,磨损量呈上升趋势,加入碳纤维可以明显地降低材料的摩擦系数和磨损量,当碳纤维含量为5%-10%时复合材料的摩擦系数和磨损量最低;加入适量固体石墨可进一步降低复合材料的摩擦系数和磨损量。 相似文献
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通过低温震荡方法制备了过氧化氢凝胶。研究了微米和纳米级颗粒状二氧化硅对过氧化氢的胶凝行为及其所形成凝胶的刺激响应性。用R/S软物质测定仪研究了某过氧化氢凝胶配方的触变性能。结果表明,二氧化硅的粒度与表面性质直接影响其胶凝能力,亲水性纳米二氧化硅比亲水性微米二氧化硅具有更好的胶凝能力,而疏水性微米和纳米二氧化硅不能胶凝过氧化氢。亲水性纳米二氧化硅的过氧化氢凝胶具有显著的温度/剪切双重刺激响应性,并随过氧化氢浓度的增加而增强。在实验的基础上,提出了凝胶形成和刺激触变的可能机理。实验发现,加入微量表面活性剂与氢氟酸,能够有效提高凝胶的稳定性。 相似文献
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介绍FP565G2全自动TAG闭口闪点测试仪的工作原理及测定方法,通过使用FP56 5G2自动闭口闪点仪对已知闭口闪点的样品进行测定,分析自动闪点仪使用的影响因素并对操作进行改进。将FP565G2测定结果与现行闭口闪点的国家标准GB/T261的测试结果进行比较,FP565G2自动闭口闪点仪重复性要求和精确度要求都在标准方法允许的误差范围内。 相似文献
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A. Lindner B. Lestriez S. Mariot C. Creton T. Maevis B. Lü hmann R. Brummer 《The Journal of Adhesion》2006,82(3):267-310
The viscoelastic and adhesive properties of a series of model, lightly crosslinked acrylic polymer networks have been investigated. The model networks were statistical copolymers of 2-ethyl-hexyl acrylate and acrylic acid or terpolymers of 2-ethyl-hexyl acrylate, acrylic acid, and stearyl acrylate synthesized in solution. All were lightly crosslinked after the polymerization was completed to obtain typical properties of pressure-sensitive adhesives. The bulk rheological properties of the networks were characterized by dynamical mechanical spectroscopy and in uniaxial extension. Their adhesive properties were tested with an instrumented probe tester fitted with a cylindrical steel probe. The presence of acrylic acid in the copolymer caused an increase in both elastic modulus and resistance to interfacial crack propagation characterized by the critical energy-release rate Gc and the incorporation of stearyl acrylate caused a decrease in both modulus and Gc. In both cases, however, the modification of Gc controlled the overall behavior. The analysis of the nonlinear elastic properties of the adhesives with the Mooney-Rivlin model provided new insights on the role played by the ratio between entanglements and crosslink points in controlling the formation and extension of the bridging fibrils observed upon debonding. 相似文献
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分别将纳米三氧化二铝(Al2O3)、纳米二氧化钛(TiO2)、纳米二氧化硅(SiO2)颗粒和碳纳米管(CNTs)填充到环氧树脂(EP)/玻璃纤维(GF)复合材料中,制备了纳米填充EP/GF复合材料,GF的体积含量为30 %。用环块摩擦试验机研究了纳米填充物对EP/GF复合材料的摩擦磨损性能的影响。结果表明,1.0 %(质量分数,下同)的CNTs能够较大幅度地降低复合材料的摩擦因数和磨损率,而纳米Al2O3、纳米TiO2和纳米SiO2颗粒可以明显提高复合材料的耐磨损性能。 相似文献
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The scratch resistance of four clearcoat formulations was evaluated using a CSM nano-scratch tester, an AMTEC-Kistler simulated
carwash tester, and a laboratory scale macro-scratching tester. Significant differences in the rank-order of all the clearcoats
were found when comparing the scratch and mar behavior using macro-scratching, nano-scratching, and AMTEC-Kistler testing.
Field vehicles were also examined where the mean and median widths of scratches found on vehicles were 237 and 141 μm, respectively.
The range of loads associated with events with the potential to create real-world scratches was found to be significantly
higher (5–35 N) than the forces needed to make scratches of the same mean size as those seen in the field (7–10 N). These
results indicated that a significant improvement in the scratch resistance of these clearcoats would be needed before customers
would notice improvements in their paint finish’s scratch resistance. 相似文献
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The cohesive peel spectra of pressure-sensitive adhesive (PSA) tapes have been measured using a non-stationary peel tester. The experimental evidence and a viscoelastic analysis based on a peel model indicate that there are no significant effects of acceleration in the normal rate region. The nonstationary peel tester can be regarded as a useful tool for testing and evaluating PSA tapes. 相似文献
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Yasar Totik 《Journal of Coatings Technology and Research》2010,7(4):485-492
Scratch tests have been used to investigate the adhesion of niobium nitride (NbN) coatings that were deposited by pulsed dc
reactive magnetron sputtering at target currents of 1.5, 2.5, and 3.5 A onto M2 tool steel and silicon wafer. The coating
adhesion on each material substrate was investigated using a progressive load scratch tester (PLST) and a multi-pass scratch
tester (MPST). Microhardness tests and scanning electron microscopy (SEM) were also used to examine the hardness and microstructure
of the NbN coatings. These results have indicated that the structural, mechanical, and adhesion properties of the NbN coatings
improve with increasing target currents. While performing PLST and MPST tests, the highest adhesion and lowest friction force
were obtained for the coatings deposited at a target current of 3.5 A. In addition, the triboscobic behaviors that were observed
from the MPST of the coatings indicated that the target currents affect the friction behavior of the coatings. 相似文献