共查询到19条相似文献,搜索用时 93 毫秒
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混凝土化学组成的研究,对提升水泥混凝土强度有着十分重要的作用。主要研究了胶凝材料体系的硅酸盐水泥的化学组分与其相对掺量、还有配合比对混凝土强度的影响。综述了不同胶凝材料的化学组成与其反应机理,要特别说明的是C_3S和4CaO·Al_2O_3·Fe_2O_3的含量对强度的影响最大。水泥熟料发生的水化反应得到的水化产物,也对其产生了一定影响。通过优化胶凝材料不同的化学组分掺量,可以有效提高水泥混凝土强度。 相似文献
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粘土/丁苯橡胶纳米复合材料的制备和性能 总被引:55,自引:4,他引:55
通过两种方法制备了粘土均匀分散于橡胶中的纳米复合材料。电子显微镜显示粘土以单层和多层的形式分散于橡胶基体中,X-光衍射显示了粘土的晶层间距得到扩充,粘土层间插入了高分子。纳米复合材料具有与用炭黑补强的材料同样的良好性能。 相似文献
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采用3种有机改性剂分别对无机粘土进行改性,然后通过熔融共混制得了天然橡胶(NR)/有机粘土纳米复合材料。通过热重分析(TGA)和X-射线衍射(XRD)表征了粘土的有机改性程度。用扫描电镜(SEM)和流变手段表征了纳米复合材料的形态和流变特性。结果表明,含有2条长烷基链和含有2个羟乙基官能团的改性剂对粘土具有更好的改性效果,但由于羟乙基官能团具有强极性,与非极性的NR相容性差,导致有机粘土在基体中大量团聚。各纳米复合材料的储能模量在低频区表现出不同程度的"二次平台"或者"上翘",在时间扫描过程中随着时间变化表现出不同的结构演变。 相似文献
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采用伊蒙粘土替代部分炭黑,研究伊蒙粘土用量对伊蒙粘土/炭黑/天然橡胶复合材料硫化特性、物理性能、动态力学性能和导热性能的影响。结果表明:随着伊蒙粘土用量增大,混炼胶的Payne效应减弱,最大转矩减小,正硫化时间缩短;硫化胶的耐热老化性能、气密性、抗冲击性能提高;添加5和7份伊蒙粘土的硫化胶物理性能和耐磨性能与未添加伊蒙粘土的硫化胶相当,且明显好于添加10和15份伊蒙粘土的硫化胶;伊蒙粘土可明显提高硫化胶的抗湿滑性能、减小滚动阻力。 相似文献
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自从丰田中心率先研究出了尼龙6/有机粘土纳米复合材料之后,聚合物/层状硅酸盐纳米复合材料引起了很多高分子科学家的关注。纳米复合材料就是一些无机填料以纳米级均匀分散在高聚物基体中形成的复合材料。粘土片层被聚合物插层或剥离可形成聚合物/粘土纳米复合材料。 相似文献
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《国际聚合物材料杂志》2012,61(4):217-228
Tensile, compressive, flexural and wear resistance properties of Hibiscus sabdariffa fiber-reinforced phenolic (Resorcinol Formaldehyde) resin matrix-based composites were evaluated to assess the possibility of using these fibers as a new eco-friendly material in engineering applications. Polymer composite samples were fabricated by a compression-molding technique developed in our laboratory. The effect of fiber dimension on mechanical properties was evaluated. The interfacial bonding between Hibiscus sabdariffa fiber and the polymer matrix has been found to affect the mechanical properties of the resorcinol formaldehyde resin matrix. It has been observed that particle-reinforced polymer composites exhibit better mechanical properties as compared to short and long fiber-reinforced polymeric composites. These composites were further subjected to an evaluation of morphological, thermal, physical (swelling and moisture absorption) and chemical properties. 相似文献
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改性白炭黑对NR/BR/SBR并用橡胶力学性能的影响 总被引:1,自引:0,他引:1
本文系统研究了经不同改性剂单独及复配改性后白炭黑对NR/BR/SBR并用橡胶力学性能的影响.结果表明:经硅烷偶联剂WD-50,WD-81以及油酸改性的白炭黑填充后并用橡胶的力学性能明显增强,抗拉强度提升到15.07 MPa,撕裂强度达到36.46 MPa,300%定伸应力提升到3.21 MPa,硬度为57 HA,拉断伸长率为869.01%,扯断永久变形为19.6%,符合普通橡胶板的国标要求.并用橡胶拉伸断面SEM照片显示,改性后的白炭黑可以较好的和橡胶基质融合. 相似文献
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This study assessed the potential of wood residues as fiber sources for wood-plastic composites (WPC) and examined the impact for intrinsic fiber properties on strength development. Sawmill sawdust, underused wood species, bark, composite panel, and pulp and paper sludge residues were sampled. Fibers were characterized for cellulose content, ash content, and fiber aspect ratio. WPC samples were formed by twin-screw extrusion compounding, followed by injection molding at three fiber proportions. WPC mechanical properties, water uptake, and water swelling increased with increasing fiber proportion, whereas tenacity decreased. WPC made with residues had lower mechanical and physical properties than those made with clean wood, with some exceptions. Kraft sludge produced one of the best WPC formulations in terms of thickness swell, water swelling, tensile strength, and impact energy. Deinking sludge produced the toughest and the most dimensionally stable WPC. Panel industry residues formed roughly similar WPC to those made with clean wood. Bark led to poorest WPC in terms of mechanical properties. High correlation coefficients were found between cellulose content, wood content, and all WPC properties except impact energy. However, the correlations between aspect ratio and the WPC were insignificant. 相似文献
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利用简便的方法制备了活性白土/壳聚糖复合物吸附剂,并通过红外光谱(FT-IR)、热重(TG)、X-射线衍射(XRD)和透射电镜对所制备的吸附剂进行表征.结果表明,壳聚糖嵌入到活性白土的片层结构中,形成了稳定的复合结构,进而增大了活性白土的片层间距,有利于提高活性白土的吸附性能.活性白土/壳聚糖复合物作为吸附剂,对草莓汁、西瓜汁、橙汁均具有较好的澄清效果.对草莓汁澄清条件为:吸附剂用量为0.02 g,35℃、吸附时间1.5h、pH 5,澄清度为69.36%;对西瓜汁的澄清条件为:吸附剂用量为0.02 g,25℃、吸附时间1.5h、pH 6,澄清度达到98.42%;对橙汁的澄清条件为:吸附剂用量为0.02 g,30℃、吸附时间1h、pH 6,澄清度为61.08%. 相似文献