抗静电LLDPE/CNT复合材料的制备及其性能研究

Preparation and Characterization of Antistatic LLDPE/CNT Composites

中文关键词: 线性低密度聚乙烯  碳纳米管  抗静电  复合材料

英文关键词: linear low density polyethylene  carbon nanotube  antistatic  composite

中文摘要:

      目的 制备特种产品用抗静电包装材料。方法 采用碳纳米管(CNT)对线性低密度聚乙烯(LLDPE)进行熔融复合改性，研究CNT含量对LLDPE电学性能、力学性能、结晶行为及热稳定性的影响，并对确定的最优体系进行应用性能考核。结果 CNT具有较大的长径比，直径为10~20 nm，纯度较高。LLDPE/CNT复合材料表面电阻率变化呈现明显的“渝渗”现象，当CNT质量分数从3%增加至5%时，其表面电阻率由10¹³ Ω骤降至10⁵ Ω。随着CNT含量增加，LLDPE/CNT复合材料的拉伸强度增加，断裂伸长率和冲击强度有所降低。CNT没有改变LLDPE的熔融行为，但其结晶度和熔点随着CNT含量增加而略有降低。LLDPE/CNT复合材料起始降解温度和最大降解速率处温度随着CNT含量增加而增加。CNT质量分数为4%的LLDPE/CNT复合材料综合性能最优，热氧老化后其表面电阻率几乎无变化，相比纯LLDPE，其熔融指数有所下降，氧化诱导时间大幅提升。结论 通过CNT对LLDPE树脂进行改性，制备了综合性能优良的抗静电LLDPE/CNT复合材料，在特种产品包装领域具有良好的应用前景。

英文摘要:

      The work aims to prepare antistatic packaging material for special products. Carbon nanotubes (CNT) were utilized to melt blending with linear low density polyethylene (LLDPE), the effect of CNT content on the electrical property, mechanical property, crystallization behavior and thermal stability were investigated. The application performance of optimal formula system was also conducted. It was shown that the CNT possessed large length diameter ratio, high purity and had a diameter of 10-20 nanometers. The percolation phenomenon was observed in LLDPE/CNT composites. With the CNT content increased from 3% to 5%, the surface resistivity decreased from 1013Ω to 105Ω sharply. With the increase of CNT, the tensile strength increased, the elongation at break and impact strength decreased. The CNT showed little influence on the melting behavior of LLDPE; however the crystallinity and melting temperature decreased and the degradation temperature increased slightly with the increase of CNT. It was also revealed that the composites with 4wt% CNT content exhibited optimal comprehensive performance. The thermo-oxidative aging had little influence on the antistatic property of LLDPE/CNT composites. The melt flow index decreased and the oxidation induction time increased compared with neat LLDPE. In conclusion, antistatic LLDPE/CNT composites with excellent comprehensive properties prepared by modifying LLDPE resin with CNT exhibit great technological potential for application in special product packaging.