Dispersion and major property enhancements in polymer/multiwall carbon nanotube nanocomposites via solid-state shear pulverization followed by melt mixing

A continuous, solventless, scalable process called solid-state shear pulverization (SSSP) in conjunction with melt mixing (MM) to produce well-dispersed polymer/multiwall CNT (MWCNT) nanocomposites was investigated. Polypropylene and two types of MWCNT was synthesized by FE-SEM were prepared by making a CNT suspension in 50/50 w/w deionized water/2-propanol through low-level bath type sonication for 1.5 h with poly(sodium 4-styrenesulfonate) as dispersant and casting on plasma-treated Si wafers. Crystallization was measured at 411 K by differential scanning calorimetry after annealing at 513 K for 5 minutes. The result shows that in nanocomposites made by SSSP, the CNT agglomerates are sharply reduced in size, forming loose structures interpenetrated by PP. Due to poor dispersion, the melt-mixed hybrid exhibits the slowest crystallization of the PP/CNT-1 systems.