功能化石墨烯-碳纳米管协同强韧化HDPE纳米复合材料的制备和性能

Preparation and Performance of Nanocomposites HDPE Toughened-reinforced Synergetically with Functionalized Graphene and Carbon Nano-tubes

使用L-天门冬氨酸连接氧化石墨烯和酸化多壁碳纳米管(WMCNT-COOH)合成杂化材料LGC,然后用纳米填料LGC填充马来酸酐接枝高密度聚乙烯(HDPE-g-MAH),用熔融共混法制备了LGC/HDPE-g-MAH纳米复合材料。对LGC杂化填料和LGC/HDPE-g-MAH纳米复合材料进行了红外分析(FTIR)、拉曼光谱分析(Raman)、X射线衍射分析(XRD)、扫描电子显微镜分析(SEM)、示差扫描量热仪分析(DSC)、热失重分析(TGA)、动态热机械分析(DMA)和力学性能测试,研究了LGC含量对LGC/HDPE-g-MAH纳米复合材料性能的影响。结果表明:L-天门冬氨连接了GO和WMCNT-COOH,三者通过酰胺键连接在一起形成LGC杂化材料。LGC杂化材料内部官能团(氨基或羧基等)与聚合物基体中的羧基发生相互作用,改善了基体与填料之间的界面。根据DMA分析,损耗因子的变化证实了LGC与基体分子链之间强烈的相互作用。热学分析结果表明:纳米复合材料的结晶温度、熔融温度和热稳定性能都提高了。力学分析表明:随着LGC含量的增加,复合材料的拉伸强度和冲击强度呈现出先增大后降低的趋势;当LGC含量为0.5%和0.75%(质量分数)时,复合材料的冲击强度和拉伸强度分别比HDPE-g-MAH提高了95.9%和62.4%。

Hybrid materials LGC were prepared with the L-aspartic acid connected graphene oxide and the acidified MWCNT （WMCNT-COOH） as raw materials. Then nanocomposites of LGC/HDPE-g-MAH with different amount of LGC were prepared by melt blending method with maleic anhydride grafted high density polyethylene （HDPE-g-MAH） as raw material and LGC as nano-fillers. The LGC hybrids and LGC/HDPE-g-MAH nanocomposites were characterized by using Fourier transform infrared spectroscopy （FTIR）, Raman spectrum （Raman）, X-ray diffraction （XRD）, Scanning electron microscope （SEM）, Differential scanning calorimetric analysis （DSC）, Thermogravimetric analysis （TGA）, Dynamic mechanical analysis （DMA） and mechanical properties characterizations. Results show that L-aspartic linked effectively GO and WMCNT-COOH, while the LGC formed via an amide bond. Functional groups （amino or carboxyl group, etc.） in LGC may interact with the carboxyl groups of polymer matrix, which improved the interface between the matrix and the filler; the changes of dissipation factor verified that strong interactions exist between LGC and HDPE-g-MAH matrix chains; therewith the crystallization temperature, melting temperature and thermal stability of nanocomposites were enhanced; while with the increasing amount of LGC, the tensile strength and impact strength of the nanocomposites increased first and then decreased, by addition of 0.5%and 0.75%（mass fraction） LGC, the impact strength and tensile strength of the nanocomposites were enhanced by 95.9% and 62.4% respectively in comparison , with the blank HDPE-g-MAH.