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聚合物基粘土纳米复合材料的流变行为研究 总被引:7,自引:0,他引:7
聚合物基粘土纳米复合材料具有与常规颗粒填充体系类似的流变特性 :在整个频率范围内 ,储能模量和损耗模量均随粘土含量的增加而变高 ,其频率依赖性会表现出非未端行为 :且当粘土含量超过临界值以后 ,储能模量会在低频区表现出似固体的平台发展。但与之不同的是前者在低粘土含量的条件下 (<10 % (wt) )就会表现出似固体行为或非末端行为。这些流变特性还会受到粘土的径厚比、化学特性、聚合物基体的分子结构参数和粘土与基体间的相互作用强度等因素的影响。聚合物基粘土纳米复合材料的流变行为是与其微观结构的形成和演化以及聚合物分子链在特定环境下的粘弹松弛过程紧密联系在一起的。本文综述了插层型、剥离型和聚合物分子链一端受限剥离型聚合物基粘土纳米复合材料在力场作用下的流变特性和粘弹松弛机理方面的研究进展。 相似文献
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聚酰胺/粘土纳米复合材料 总被引:18,自引:1,他引:17
聚酰胺/粘土纳米复合材料是一种新型的有机-无机纳米复合材料。在无机物含量远少于常规填充复合材料的情况下就可以具有较好的力学性能、阻隔性能等,热稳定性能也显著提高,并具有阻燃性和各向异性。是一种性能优异的、具有广泛应用前途的纳米复合材料。综述了该纳米复合材料的制备、性能和应用前景等。 相似文献
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聚壳糖模板法制备纳米硒 总被引:12,自引:0,他引:12
报道了一种利用天然高分子壳聚糖为软模板水相制备纳米硒的方法。研究了反应时间、反应物浓度、温度、超声等实验条件对产物粒度大小、形貌的影响。结果表明 ,当n(Vc)∶n(H2 SeO3 ) =4∶1、壳聚糖质量分数为 1 2 0× 10 -4、常温下反应 2h时 ,可得到均匀稳定的球形纳米硒颗粒 ,平均粒径约 5 0nm ,并随反应体系的总浓度增加而减小。在 80℃反应时 ,得到了棒状纳米硒。采用紫外光谱、红外光谱、X射线衍射和透射电镜等对产物进行了结构分析和形貌观察。 相似文献
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提出了一种温和条件下制备交联聚丙烯酸胺毛细管凝胶电泳柱的新方法──预聚合法.讨论了制备过程中的问题,获得了凝胶组成、毛细管内径及长度等不同的交联聚丙烯酸胺毛细管凝胶电泳柱.采用激光回射干涉检测技术,实现了蛋白质标准样品的毛细管凝胶电泳在柱分离检测. 相似文献
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Polyurethane (PU) has been prepared by using polyether polyol (jagropol oil) and 1,6- hexamethylene diisocyanate (HMDI) as a cross-linker. The organically modified montmorillonite clay (MMT) is well-dispersed into urethane matrix by an in situ polymerization method. A series of PU/MMT nanocomposites have been prepared by incorporating varying amounts of nanoclay viz., 1, 3, 5 and 6 wt %. Thermogravimetric analysis (TGA) of the PU/MMT nanocomposites has been performed in order to establish the thermal stability and their mode of thermal degradation. The TGA thermograms exhibited the fact that nanocomposites have a higher decomposition temperature in comparison with the pristine PU. It was found that the thermal degradation of all PU nanocomposites takes place in three steps. All the nanocomposites were stable up to 205°C. Degradation kinetic parameters of the composites have been calculated for each step of the thermal degradation processes using three mathematical models namely, Horowitz–Metzger, Coats–Redfern and Broido's methods. 相似文献
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Chao Jun JING Liu Sheng CHEN Yi SHI Xi Gao JIN 《中国化学快报》2005,16(8):1117-1120
The synthesis of poly(2-methoxy-5-(2'-ethyl-hexyloxy)-l,4-phenylenevinylene) (MEH-PPV) in the presence of organophilic montmorillonite (OMMT) was reported and the exfoliated MEH-PPV/OMMT nanocomposites was obtained by controlling the ratio of the monomer to the OMMT. 相似文献
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The immobilization of enzymes such as cellulase by radiation polymerization of dispersed polyurethane prepolymer was studied using tolylene-2,4-diisocyanate and 2-hydroxyethyl methacrylate. The polyurethane particles were obtained by the dispersion of polyurethane prepolymer followed by radiation polymerization, in which the enzyme was immobilized on its surface by convalent bonding. The particle diameter of immobilized enzyme particles varied with monomer concentration and composition. The enzymatic activity of immobilized enzyme particles varied with the temperature of dispersion and irradiation, and decreased with increasing particle diameter. 相似文献
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Different polymerizable ammonium surfactants were successfully synthesized via Michael‐addition and quaternarization reactions. Organoclays containing reactive methacrylate groups were prepared by the cationic exchange process. Intercalated nanocomposites were produced by UV initiated polymerization with 5 wt.‐% organophilic clay loading. DMTA tests and tensile analysis implied that a long chain polymerizable modifier could crosslink with the polymer matrix, and mechanical and tensile properties were enhanced dramatically about 80%. Water sorption was not elevated, which was determined by the polymer itself and the hydrophobicity of the modifier, although the water permeation was improved.