Abstract Composites of polypropylene (PP) and graphite nanosheets (GN) are prepared by melt blending PP with a master batch of GN suspended in atactic polypropylene (Mw = 129.000 g/mol). aPP/GN master batches were obtained by wet ball-milling graphite in toluene using the aPP as dispersant. The procedure gives single flakes of GN with crystallite out-of-plane thickness as low as 17.7 nm. PP/aPP/GN composites were obtained with finely dispersed GN, predominantly as single nanosheets from master batches containing aPP dispersant and graphite. Crystallization of the iPP in the composites is facilitated by the presence of aPP and GN. PP spherulites are formed as the graphitic fillers act as strong nucleating agents: the dimensionality of the crystal growth (n = 2-3) and the crystallinity increases with increasing filler content in isothermal and non-isothermal crystallizations. The yield strength of the composites can be enhanced up to 20% by the presence of GN; the presence of aPP counteracts a decrease in elongation at break. Composites prepared from parent graphite or GN without aPP show larger aggregates of nanosheets in the composites.

中文翻译：

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石墨纳米片 - 使用无规聚丙烯作为分散剂的甲苯分层石墨聚丙烯复合材料

摘要 聚丙烯 (PP) 和石墨纳米片 (GN) 的复合材料是通过将 PP 与悬浮在无规立构聚丙烯中的 GN 母料 (Mw = 129.000 g/mol) 熔融共混制备的。使用 aPP 作为分散剂，通过在甲苯中湿球磨石墨获得 aPP/GN 母料。该过程产生具有低至 17.7 nm 的微晶面外厚度的单片 GN。PP/aPP/GN 复合材料是通过精细分散的 GN 获得的，主要是来自含有 aPP 分散剂和石墨的母料的单个纳米片。aPP 和 GN 的存在促进了复合材料中 iPP 的结晶。当石墨填料作为强成核剂时，会形成 PP 球晶：晶体生长的维数 (n = 2-3) 和结晶度随着等温和非等温结晶中填料含量的增加而增加。GN的存在可使复合材料的屈服强度提高20%；aPP 的存在抵消了断裂伸长率的降低。由母体石墨或没有 APP 的 GN 制备的复合材料在复合材料中显示出更大的纳米片聚集体。