Preparation, structure and thermal stability of Cu/LDPE nanocomposites
Preparation, structure and thermal stability of Cu/LDPE nanocomposites
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DOI：
10.1016/j.matchemphys.2005.05.010
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发表时间：
2006-01
影响因子：
4.6
通讯作者：
X. Xia;S. Cai;C. Xie
中科院分区：
文献类型：
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作者：
X. Xia;S. Cai;C. Xie
采用熔融共混技术在单螺杆挤出机中制备了铜/低密度聚乙烯（Cu/LDPE）纳米复合材料。采用x射线衍射（XRD）、扫描电镜（SEM）、x射线能谱（EDS）、差示扫描量热（DSC）和热重分析（TGA）对其结构和热特性进行了表征。XRD、SEM和SEM - eds cu能谱分析结果表明，纳米复合材料是聚合物和铜纳米粒子的杂化产物，铜纳米粒子的聚集体总体上分布均匀。结果还表明，由于铜纳米粒子的存在和相同的冷却条件，纳米复合材料与纯LDPE基础树脂具有不同的晶体结构和相同的取向特性。DSC结果表明，纳米铜颗粒的加入降低了复合材料的熔融温度，但提高了复合材料的结晶温度，降低了复合材料基体的结晶度。TGA结果表明，铜纳米粒子的存在提高了纳米复合材料的热稳定性，与纯LDPE相比，该实验的热稳定性最高提高了18℃。热重分析结果还表明，铜纳米粒子的掺入对Cu/LDPE纳米复合材料热稳定性的影响不同于非金属纳米粒子对聚合物/非金属纳米复合材料和铜微粒子对Cu/LDPE微复合材料热稳定性的影响。当Cu/LDPE纳米复合材料中铜纳米颗粒的含量大于2wt.%时，其热稳定性的增加幅度减小。这种差异可能是由于金属纳米粒子的活性远远高于非金属纳米粒子，以及不同铜颗粒的尺寸效应不同造成的。
Copper/low-density-polyethylene (Cu/LDPE) nanocomposites have been prepared using a melt-blending technique in a single-screw extruder. Their structure and thermal characteristics are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results of XRD, SEM and SEM–EDS Cu-mapping show that the nanocomposites are a hybrid of the polymer and the copper nanoparticles, and the copper nanoparticles aggregates were distributed uniformly in general. The results also show that the nanocomposites and the base resin, the pure LDPE, have a different crystalline structure and the same oriented characteristics owing to the presence of copper nanoparticles and the same cooling condition. The results of DSC show that the incorporation of copper nanoparticles can decrease the melting temperatures but increase the crystallization temperatures, and can lower the crystallinity degree of the matrix of the composites. The results of TGA show that the presence of copper nanoparticles can improve the thermal stability of the nanocomposites, a maximum increment of 18°C is obtained comparing with the pure LDPE in this experiment. The results of TGA also show that the influence of the incorporation of the copper nanoparticles on the thermal stability of the Cu/LDPE nanocomposites is different from that of the non-metal nanoparticles on the polymer/non-metal nanocomposites and the copper microparticles on the Cu/LDPE microcomposites. The increase of the thermal stability of the Cu/LDPE nanocomposites will decrease when the content of the copper nanoparticles is more than 2wt.%. The difference might be caused by the fact that the activity of the metal nanoparticles is much more higher than that of the non-metal nanoparticles, and the different size effect the different copper particles has.