The effect of carbon nanotubes on the rheology and electrical resistivity of polyamide 12/high density polyethylene blends

Different melt mixing sequences were applied to incorporate multiwalled carbon nanotubes (CNTs) into blends prepared from high density polyethylene (PE) and polyamide 12 (PA). Electron microscopy, rheology and electrical resistivity were used to characterize the morphology and microstructure. At a composition of 75PA/25PE, presence of CNT at the interface promoted by premixing the CNTs in the PE phase, resulted in finer phase morphology and a decrease in the resistivity of up to five decades relative to other mixing procedures used. At a composition of 25PA/75PE, premixing the CNT in the PA phase resulted in their segregation inside and around the PA domains and a four decade lower resistivity. Interestingly, compounds that yielded the lowest resistivity were also characterized by increased low frequency melt storage modulus (G′) which indicates the existence of a correlation between the two properties.