碳纳米球/聚乙烯复合物的制备与表征

The Preparation and Characterization of Carbon Nanosphere/Polyethylene Composites

以碳纳米球为载体,经格氏试剂处理后,与TiCl4反应制成负载型Ziegler-Natta催化剂,在AlEt3存在下,催化乙烯聚合,原位制备聚乙烯(PE)/碳纳米球(CSs)复合物,催化剂活性达5.7×106gPE/(molTi·h),聚乙烯分子量为4.9×105.HRTEM和SEM结果表明,常压聚合条件下聚乙烯/CSs复合物为核-壳结构,颗粒呈圆形,直径约为1μm左右,复合物颗粒中包含碳纳米球.介电分析结果表明,由于碳纳米球的引入,复合物的介电性能相较于普通聚乙烯有明显的提高,从而提高了聚乙烯的抗静电性能,且介电常数和介电损耗都随着聚合时间的延长而降低.此外,采用WAXD,DSC和TGA表征了PE/CSs复合物的结晶性能和热性能,结果表明聚乙烯/CSs复合物具有好的结晶性能和热稳定性能.

Carbon nanospheres （CSs） treated with Grignard reagent were used as carrier,which reacted with TiC14 to form supported Ziegler-Natta catalyst. In the presence of A1Et3, this catalyst catalyzed ethylene polymerization to obtain PE/CSs composites in situ. The catalytic activity for ethylene polymerization was up to 5.7 ×10^6 gPE/（molTi·h） and the weight average molecular weight of the obtained polymer was 4.9 × 10^5. As characterized by TEM and SEM,the particles of obtained composites were spherical with diameters of about 1 μm,furthermore,they featured a core-shell structure as expected. The dielectric analysis results indicated that compared with normal polyethylene, by the introduction of carbon nanospheres the PE/CSs composites dielectric properties experienced an obvious increase, which improved the anti-static function of PE. The dielectric result showed a slight decline of the dielectric constant of PE/CSs composites with increase of the polymerization time,and lower dielectric loss was also observed due to the decrease of CSs content in PE/CSs composites. Moreover, the crystalline properties and thermal stability of the PE/CSs composites were determined by WAXD, DSC and TGA. It turned out that PE/CSs composite possessed good crystalline properties and thermal stability.