共查询到20条相似文献,搜索用时 234 毫秒
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本文从电镀层的表面形态及硅烷偶联剂处理的表面这一角度探讨了二氧化硅沉析镀锌层对橡胶粘合性能的影响。结果表明,表面粗糙高度约为7um的纯镀锌层及表面粗糙的二氧化硅沉析镀锌层,其与橡胶的粘合强度比表面光滑时的粘合强度高2~5倍,由此证实了粗糙表面的锚固效果。然而,从它们粘合界面破坏的情况看,镀层表面出现剥离破坏的几率较高。与此相对比,经过烷硅偶联剂处理的粗糙状二氧化硅沉析镀锌层,其与橡胶的粘合性能则有很大改进,虽经盐雾试验100小时后,试样的粘合强度仍保持在试验前的水平,镀层表面出现剥离破坏的几率几乎为零,而且,即使不涂底胶,偶联剂处理的试样也表现出相当牢固的粘合性能。 相似文献
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为了解决低磁性电连接器用铝合金表面镀锌的失效问题,采用金相显微镜、扫描电镜和能谱仪分析了失效部位镀层的微观结构。结果显示,产品失效是镀后热风吹干过程中局部锌层受到而氧化或结合力下降所致。最后提出改用冷风吹干,必要时采用化学镀镍层代替电镀锌层。 相似文献
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Howard S. Bender 《应用聚合物科学杂志》1969,13(6):1253-1264
A correlation has been made between dynamic mechanical properties and impact resistance of a multicoat paint system. It has been determined that the shear or rigidity modulus and damping of free primer films are some of the parameters that control the impact characteristics of the system. Those films of low modulus and high damping show the best chip resistance. A series of physical and chemical modifications were made on the primer and chipping results were compared with dynamic mechanical properties of free paint films. It was found that increasing cure temperature, addition of catalysts, decreasing the oil length of the resin, increasing the amount of pigmentation and increasing the tension and strain rate all led to increased paint chipping and increases in the modulus of rigidity. Two new primers were synthesized which incorporated the above results and were found to give increased gravel impact resistance. 相似文献
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以凹土代替部分二氧化钛制备涂料,通过改变凹土的用量测定涂料的性能变化情况,并对凹土进行超细粉碎处理前后对涂料性能的影响进行对比。凹土替代二氧化钛,不但可以改善涂料的某些性能,还可以降低涂料成本,但用量不宜太多,与适量的碳酸钙混合使用效果更好。相同的代替量,超细凹土优于原粉凹土。 相似文献
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A new hydroxymethyl-pendant salan (3) containing a chiral backbone and an extra O4 cavity has been prepared through a facile one-pot procedure. The ligand has been characterized by ESI-MS, elemental analysis and 2D NMR techniques. To continue our previous work on the catalytically asymmetric F-C reactions using multimetallic complexes involving salan-type ligands, we investigated the applicability of 3 for both asymmetric Henry and F-C reactions, in comparison with previously reported results using salans 1 and 2. It was revealed that although 3 was not a suitable ligand for homometallic copper-catalyzed Henry reaction, it was effective for the hetereobimetallic Cu/Zn-catalyzed asymmetric F-C reaction, affording desired alkylated product with good yield and moderate enantiomeric excess (ee), after screening of various catalyst combinations. 相似文献
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