多壁碳纳米管/聚丙烯复合材料的晶型及非等温结晶动力学

Crystallographic Form and Non-isothermal Crystallization Kinetics of Multiwalled Carbon Nanotube/Polypropylene Composites

采用熔融共混法制备了多壁碳纳米管/聚丙烯(MWNT/PP)复合材料,利用X射线衍射法(XRD)、差示扫描量热法(DSC)分别研究了纯聚丙烯(PP)及MWNT/PP复合材料的晶型和非等温结晶动力学行为,并运用Mo法研究了纯PP及MWNT/PP复合材料的非等温结晶动力学行为。结果表明,多壁碳纳米管(MWNT)的加入使PP发生了由β晶型向α晶型的转变。MWNT在结晶过程中具有异相成核效应,提高了PP的结晶温度和结晶速率。MWNT/PP复合材料的结晶活化能均明显高于纯PP。MWNT的加入使PP在单位时间内达到一定结晶度所需的降温速率减小。

Multiwalled carbon nanotube/polypropylene （MWNT/PP） composites were prepared by melt blending. The crystallographic form and non-isothermal crystallization kinetics of polypropylene （PP） and MWNT/PP composites were investigated by X ray diffraction （XRD） and differential scanning calorimetry （DSC）. Mo equation was used to indicate the kinetics of non-isothermal crystallization of PP and MWNT/PP composites. The results show that, the addition of multiwalled carbon nanotube （MWNT） leads to the transition of PP from 13 crystallographic form to a crystallographic form. MWNT has an obvious nucleating effect on the crystallization of PP, increasing crystallization temperature and crystallization rate. On the contrary, the activation energies of MWNT/PP composites are higher than that of pure PP. MWNT can decrease the cooling rates of PP needed to reach relative crystallinities in a unite time.