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91.
尼龙/聚丙烯合金的性能与制备 总被引:4,自引:0,他引:4
介绍国外各种尼龙/聚丙烯合金的性能和制备工艺。聚合物合金的相容性原理,以及PA/PP合金适用的各种相容剂。 相似文献
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93.
氢氧化镁表面处理工艺对阻燃PP性能的影响 总被引:11,自引:0,他引:11
为改善氢氧化镁[Mg(OH)2]与聚丙烯(PP)的相容性,将来源不同的两种Mg(OH)2进行表面处理后加入PP中,并对其表面性能、阻燃性能和力学性能进行了测试。结果表明,PP中添加占复合材料总质量65%的Mg(OH)2,其阻燃级别能达到V-0级,氧指数接近30%;且改性后的Mg(OH)2能大大改善阻燃PP的力学性能。同时通过比较不同偶联剂和处理方法对包覆效果的影响,选出了Mg(OH)2表面处理的较优工艺。 相似文献
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95.
The confined etchant layer technique has been applied to fabricate complex three-dimensional microstructures on nitinol for the first time. HF and HNO3 were locally and simultaneously electrogenerated at the mold surface to etch a nitinol workpiece. NaOH was used as an efficient scavenger to confine the etchant close to the mold. Cyclic voltammetry was employed to study the electrochemical behavior of a Pt electrode in the etching solution in order to choose an appropriate potential for etchant generation on the mold. The thickness of the confined etchant layer was estimated to be several micrometers by inspecting the deviation of the sizes of the etched spots from the sizes of those on the microelectrode. Thus, the composition of the electrolyte could be optimized for better etching precision. By optimizing the composition of the electrolyte, complex microstructures on a Pt-Ir mold bearing the logo “XMU” of Xiamen University were successfully fabricated on nitinol. The etched patterns were approximately negative copies of the mold, and the precision of duplication could easily reach the micrometer scale. 相似文献
96.
Aeree Seo 《Electrochimica acta》2006,52(4):1603-1611
Carbon-supported Pt-based ternary alloy electrocatalysts were prepared by incipient wetness method in order to elucidate the origin of the enhanced activity of oxygen reduction reaction in PEMFC. To measure the catalytic activity and stability of the cathode alloy catalysts (electrodes containing Pt loading of 0.3 mg/cm2, 20 wt.% Pt/C, E-TEK), the I-V polarization curves were obtained. All alloy catalysts showed higher performances than Pt/C. It can be concluded that as platinum formed alloys with transition metals, the electronic state of Pt and the nearest neighbor Pt-Pt distance changes, which significantly influence the electrocatalytic activity for oxygen reduction.Long-term stability test was performed with the Pt6Co1Cr1/C alloy catalyst for 500 h. According to XPS analysis, the lower oxide component with Pt6Co1Cr1/C electrocatalyst provides a large portion of platinum in metallic species in the electrocatalyst and it seems to be mainly responsible for its enhanced activity towards oxygen reduction. 相似文献
97.
98.
Changmook Kim Younghun Kim Pil Kim Jongheop Yi 《Korean Journal of Chemical Engineering》2003,20(6):1142-1144
A salt of stearic acid, i.e., magnesium stearate [(C17H35COO)2Mg], can be used as a chemical template for the formation of mesoporous alumina, and is a less expensive reagent than stearic
acid. Mesoporous alumina prepared using this cost-effective surfactant shows similar pore properties with respect to pore
size (3.5 nm) and surface area (above 300 m2Vg) to that prepared using stearic acid. In addition, textural porosity, arising from non-crystalline intraaggregate voids
and spaces, was effectively removed by the addition of magnesium nitrate. The entire transformation from aluminum hydroxide
to active alumina was performed at 550 °C, and the crystallinity of the product was confirmed by powder XRD analysis.27A1 MAS NMR result shows the phase of mesoporous alumina is the γ-alumina form. 相似文献
99.
采用物理共混以及化学交联模压发泡成型工艺制备聚乙烯-醋酸乙烯酯(EVA)/乙丙橡胶(EPDM)/聚氯乙烯(PVC)三元聚合物合金软泡沫体,并制成贴布复合衬垫。讨论了该体系的相容性,动态共交联与发泡的适配,以及贴布复合,造型等问题,结果表明,该衬垫可完合替代国外同类先进产品。 相似文献
100.
PPO与PA,PP是不相容的,制造PPO PA及PPO PP合金需要提高合金中两组分的相容性。本文叙述改善相容性的原理和途径、两种合金的特点及其重要性能。 相似文献