纳米ZrO_2/LLDPE复合材料的非等温结晶动力学

Non-isothermal Crystallization Kinetics of Nano-ZrO_2 /LLDPE Composites

以纳米氧化锆(ZrO2)作为成核剂改性线性低密度聚乙烯(LLDPE),采用差示扫描量热仪(DSC)研究了含不同ZrO2质量分数的纳米ZrO2/LLDPE复合材料的非等温结晶行为,并分析了基于Jeziorny理论和莫志深理论的结晶动力学参数,利用Kissinger法和Takhor法计算了结晶活化能。结果表明:纳米ZrO2的加入使结晶速率变慢,阻碍了晶粒的生长;与LLDPE相比,当纳米ZrO2质量分数为10%时,复合材料的活化能降低,纳米ZrO2在结晶过程中起到异相成核的作用;而纳米ZrO2质量分数为5%时,复合材料的活化能增大,纳米ZrO2的异相成核作用不明显。

Nano-zirconia （nano-ZrO2） was used as nucleation agent to improve the properties of linear low density polyethylene （I.LDPE）. The behaviors of nano-ZrO2/LLDPE composites contenting various mass fractions of ZrO2 were investigated by means of differential scanning calorimetry （DSC） in the non-isothermal crystallization process. Jeziorny and Mo methods were used to analyze the parameters of non isothermal crystallization kinetics. The activation energies in crystallization were evaluated by Kissinger and Takhor methods. The results demonstrate that the addition of ZrO2 slowed the crystallization rate of LLDPE and restrained the crystal growth. The addition of 10wt% nano ZrO2 decreased the activation energy of LLDPE, which improved the heterogeneous nucleation during non isothermal crystallization process of LLDPE. The activation energy of LLDPE increased and heterogeneous nucleation was not obvious for LLDPE with 5wt% of nano-ZrO2.