Carbon nanotube localization at interface in cocontinuous blends of polyethylene and polycarbonate

Abstract

A new technique to show good electroconductivity was proposed using carbon nanotube (CNT) localization in cocontinuous immiscible polymer blends comprising ultrahigh-molecular-weight polyethylene (UHMWPE) and polycarbonate (PC). When UHMWPE was added to PC/CNT in the molten state in an internal mixer, CNTs started moving to the UHMWPE phase. However, CNTs require a long time to diffuse into the UHMWPE phase owing to a low diffusion constant. Consequently, they remain at the interface between PC and UHMWPE. When the blends have cocontinuous structure, the localized CNTs at the phase boundary act as a conductive path, leading to a good electroconductivity. Although a similar morphology is obtained by adjusting the balance of interfacial tensions among polymers and CNT, it is difficult to find a system showing appropriate interfacial tensions. As the present method is applicable to various polymer blends, it will be an important technique to prepare a conductive nanocomposite.

Recycled polyethylene/polycarbonate blends compatibilized with oxidized polyethylene/CaCO3

“…Considering its global production quantity of over five million tons a year, 6 recycled PC is a useful feedstock to modify the properties of other low‐strength polymers such as LDPE. However, LDPE and PC resins are thermodynamically immiscible due to polarity differences and the low entropy of mixing and getting phase‐separated during thermo‐mechanical processing 7–12 . Interestingly, plastic industries often use calcium‐based minerals obtained from limestone or calcite (e.g., CaCO 3 ) as an additive for improving the surface finish of the products.…”

Conductive polycarbonate composites prepared by a ternary polymer blend approach involving sea‐island‐type interfacial carbon black networks

“…So far, a large number of CPCs have been successfully prepared using many types of binary polymer blends and various types of conductive fillers. [1][2][3][10][11][12][13][14][15][16] Ternary polymer blends have more complicated phase structure than binary polymer blends. For example, a ternary polymer blend consisting of two major components and one minor component can have four possible morphologies [17][18][19] : tricontinuous structure with the minor component as the continuous interphase of the two major phases, the minor component as islands inside one of the two major phases, and partial wetting, that is, the minor component as droplets located at the interface of the two major phases.…”

“…The percolation threshold significantly decreases via double percolation mechanism. So far, a large number of CPCs have been successfully prepared using many types of binary polymer blends and various types of conductive fillers 1–3,10–16 …”

The Localization Behavior of Different CNTs in PC/SAN Blends Containing a Reactive Component

“…If the filler is pre-localized in the thermodynamically less preferred component, or localizes there due to a lower melting or softening temperature of this component, a too short mixing time and too high melt viscosity may hinder reaching the thermodynamically favorable localization [ 32 , 33 , 34 ]. By adapting the mixing sequence and conditions in a suitable way, it is even possibly to localize such nanofillers at the interface [ 26 , 31 , 33 , 35 , 36 , 37 , 38 , 39 ]. Kinetic hindrance of migration from a non-preferred to a preferred component can also occur, as in the case of spherical particles, such as carbon black and nanotube agglomerates or layered structures, such as phyllosilicates and nano-graphite, resulting in interface localization [ 40 , 41 , 42 ].…”