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921.
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923.
Poly(propylene carbonate)/aluminum flake composite films with enhanced gas barrier properties
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A series of poly(propylene carbonate) (PPC)/aluminum flake (ALF) composite films with different ALF contents were prepared via a melt‐blending method. Their cross‐section morphologies, thermal properties, tensile strength (TS), and gas barrier properties were investigated as a function of ALF contents. SEM images reveal the good dispersion and orientation of ALF along with melt flow direction within PPC matrix. The oxygen permeability coefficient (OP) and water vapor permeability coefficient (WVP) of the composite films decrease continuously with ALF contents increasing up to 5 wt %, which are 32.4% and 75.2% that of pure PPC, respectively. Furthermore, the TS and thermal properties of PPC/ALF composite film are also improved by the incorporation of ALF particles. The PPC/ALF composite films have potential applications in packaging area due to its environmental‐friendly properties, superior water vapor, and oxygen barrier characteristics. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41663. 相似文献
924.
采用气压浸渗法制备中体积分数电子封装用 Al/Si/SiC 复合材料。在保证加工性能的前提下,用与 Si 颗粒相同尺寸(13 μm)的 SiC 替代相同体积分数的硅颗粒制得复合材料,并研究其显微组织与性能。结果显示,颗粒分布均匀,未发现明显的孔洞。随着 SiC 的加入,强度和热导率将得到明显提高,但热膨胀系数变化较小,对使用影响也不大。讨论几种用于预测材料热学性能的模型。新的当量有效热导被引入后,H-J 模型将适用于混杂和多颗粒尺寸分布的情况。 相似文献
925.
In this paper, we describe the reliability evaluation for MEMS devices, especially designed tbr DVD(Digital Video Disk) application.
These MEMS devices are fabricated as a mirror plane (shutter plane) used in DVD data picking up. This micromachined annular
shutter mirror (ASM) acts as an adjusting means of the numerical aperture. The electrostatic force can drive the upper plane
up and down for focusing or defocusing of incident laser beam to the selected recording plane. So we need to evaluate the
micromechanical properties of thin film structural materials to ensure the reliability of those MEMS devices. For those, we
perfl)rm the fatigue tests onto the devices in the conditions of much accelerated than those of normal driving. The applied
electrostatic force can induce the change of the thin film properties, and those are observed by direct and indirect methods
(XRD and electrical system). And then, we compare the fatigue effects with electrical, optical data from the intentionally-fatigue-applied
specimen and as-fabricated one under accelerated conditions. Consequently, we can estimate the structural reliability and
will provide the effective suggestion data for the fabrication of stable mirror material before commercialization. 相似文献
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927.
Sip/1 199, Sip/4032 and Sip/4019 environment-friendly composites for electronic packaging applications with high volume fraction of Si particles were fabricated by squeeze-casting technology. Effects of microstructure, panicle volume fraction, panicle size, matrix alloy and heat treatment on the electrical properties of composites were discussed, and the electrical conductivity was calculated by theoretical models. It is shown that the Si/Al interfaces are clean and do not have interface reaction products. For the same matrix alloy, the electrical conductivity of composites decreases with increasing the reinforcement volume fraction. As for the same panicle content, the electrical conductivity of composites decreases with increasing the alloying element content of matrix. Panicle size has little effects on the electrical conductivity. Electrical conductivity of composites increases slightly after annealing treatment. The electrical conductivity of composites calculated by P.G model is consistent with the experimental results. 相似文献
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