Melt viscosity behavior of C60 containing star polystyrene composites
Melt viscosity behavior of C60 containing star polystyrene composites
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DOI：
10.1039/c3sm00103b
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发表时间：
2013-06
期刊：
影响因子：
3.4
通讯作者：
Haiying Tan;Donghua Xu;D. Wan;Yujie Wang;Lu Wang;Jun Zheng;Feng Liu;L. Ma;T. Tang
中科院分区：
文献类型：
--
作者：
Haiying Tan;Donghua Xu;D. Wan;Yujie Wang;Lu Wang;Jun Zheng;Feng Liu;L. Ma;T. Tang
研究了三臂和六臂星形聚苯乙烯(SPS)/C60复合材料的熔体粘度行为。研究发现，SPS/C60复合材料熔体粘度的变化趋势与SPS支链的相对分子质量和C60的含量有关。当SPS的mA小于聚苯乙烯(PS)缠结临界分子量(Mc)时，低C60含量的SPS/C60复合材料在0.05rad S−1(η*0.05)下的复粘度低于纯SPS。然而，当Ma大于PS的Mc时，SPS/C60复合材料的η*005值高于纯SPS。这些结果与前人对线型PS/C60复合材料熔体粘度行为的研究结果相反(A.Tuteja et al.，Macromolics，2007，40,9427-9434)，当脂多糖的相对分子质量小于PS的Mc时，LPS/C60复合材料在低剪切频率下的η*高于纯LPS，而当LPS的相对分子质量大于PS的Mc时，LPS/C60复合材料在低剪切频率下的η*低于纯LPS。探讨了SPS/C60复合材料熔体粘度行为的可能机理。预期SPS的拓扑结构导致C60在SPS基质中的分散程度高于C60在脂多糖基质中的分散状态。当SPS的相对分子质量不同时，SPS与C60的接触状态也可能不同，从而使C60起到润滑剂或屏障的作用，导致SPS/C60熔体粘度的降低或增加。
The melt viscosity behavior of three-arm and six-arm star polystyrene (SPS)/C60 composites was studied. It was found that the changing trend in the melt viscosity of SPS/C60 composites depended on the molecular weight of the arm chain (Ma) of SPS and the content of C60. When the Ma of SPS was smaller than the critical molecular weight for the entanglement (Mc) of polystyrene (PS), the complex viscosity obtained at 0.05 rad s−1 (η*0.05) of SPS/C60 composites with a low content of C60 was lower than that of pure SPS. When the Ma was larger than the Mc of PS, however, the η*0.05 of the SPS/C60 composites was higher than that of pure SPS. These results were contrary to the previous work on the melt viscosity behavior of linear PS (LPS)/C60 composites (A. Tuteja et al., Macromolecules, 2007, 40, 9427–9434), where the η* at low shear frequencies of LPS/C60 composites was higher than that of pure LPS when the molecular weight (Mw) of LPS was smaller than the Mc of PS, and the η* at low shear frequencies of LPS/C60 was lower than that of pure LPS when the Mw of LPS was larger than the Mc of PS. The possible mechanism behind the melt viscosity behavior of SPS/C60 composites was discussed. It was expected that the topological structure of SPS induced a more heterogeneous dispersion of C60 in the SPS matrix than the dispersion state of C60 in the LPS matrix. When the molecular weight of SPS was different, the contact states between SPS and C60 might also be different, which would make C60 act as a lubricator or barrier, leading to the reduction or increase of the melt viscosity of SPS/C60, respectively.