High-speed shear dispersion of MWCNTs assisted by PVP in water and its effective combination with wet-mixing technology for NR/MWCNTs nanocomposites

Due to their advantages of low lost, low filling, high-performance and multifunction, multi-walled carbon nanotubes (MWCNTs) are ideal filler for preparing high-performance and multifunctional rubber-based nanocomposites. However, the poor dispersion of MWCNTs in rubber matrix and their weak interfacial adhesion with rubber matrix limit their industrial applications seriously. Herein, natural rubber (NR)/MWCNTs nanocomposites (NMNCs) with good static and dynamic mechanical properties, electrical and thermal conductivity have been successfully prepared via high-speed shear dispersion of MWCNTs assisted by polyvinylpyrrolidone in water and its effective combination with rubber wet-mixing technology, on the basis of the systematic optimization of the most common dispersants and exfoliation methods of carbon nanotubes (CNTs). Compared with NMNCs prepared by traditional dry-mixing technology (D-NMNCs), NMNCs prepared by wet-mixing technology (W-NMNCs) in this work exhibit better tensile properties, lower compression temperature rise and DIN abrasion, higher electrical and thermal conductivity, better ice and wet-slip resistance (i.e., the higher loss tangents at -20 and 0 degrees C, respectively), and lower rolling resistance (i.e., the lower loss tangent at 60 degrees C), benefiting from the better dispersion of MWCNTs and the stronger interface interaction of NR-MWCNTs in W-NMNCs. In a word, the preparation route of W-NMNCs developed in this work is very suitable for industrialization and conductive to breaking the insurmountable "Devil's Triangle" problem in tire industry, and W-NMNCs have potential high-technology applications in green, antistatic, and heat-dissipation tires, antistatic conveyors, vibration absorption, and so forth.