正应力支配下混合顺序对PA6/HDPE/CNTs体系结构及性能的影响EI北大核心CSCD

利用自行研制的叶片式混炼装置,实现了正应力支配下聚合物复合体系的熔融共混。实验研究了混合顺序以及混合时间对高密度聚乙烯(HDPE)/尼龙6(PA6)/碳纳米管(CNTs)共混物的微观结构、流变特性、热性能及宏观力学性能的影响。结果表明:正应力支配作用能在短混合时间内实现PA6粒子和CNTs的均匀分散,分散效率高;相比于将HDPE,PA6,CNTs三者同时共混或者是先将PA6与CNTs混炼制成母料,再与HDPE共混这两种混合顺序,先将HDPE与CNTs混炼制成母料,再与PA6共混制得的共混物中分散相PA6粒径最小,分散更均匀,共混物的热性能以及力学性能更好。

Microstructure and properties of PA6/HDPE/CNTs blends of different mixing sequences under normal stress dominated flow field

Melt blending method dominated by normal stress for polymer-based composite was realized via a self-developed vane mixer.Effects of mixing sequences and mixing time on the microstructure,rheological properties,thermal properties and tensile strength of PA6/HDPE/CNTs ternary blend were experimentally investigated.SEM results show that the normal stress flow field can realize the uniform dispersion of PA6 and CNTs in a short time.Compared with the other two mixing sequences,the blend of the mixing sequence that HDPE and CNTs are firstly mixed to form the masterbatch,and then the masterbatch is mixed with PA6(HDPE/CNTs+PA6)has the smallest PA6 particle size;DSC results show that Xc is significantly affected by the mixing sequence;mechanical properties show that the better tensile strength is obtained when the mixing sequence is HDPE/CNTs+PA6 and proper mixing time can further improve the tensile strength of the blend.The results aforementioned indicate that the normal stress flow field provides enough energy for the CNTs to overcome the energy barrier of the HDPE/PA6 two-phase interface and migrate into the PA6 phase,which proves that the normal stress flow field has higher dispersion efficiency.