Facile engineering strategy to control polymer chain structure for enhanced dispersion, electrical and sensing properties of nanocomposites

Preventing the aggregation of nanofillers and inducing uniform filler dispersion are key parameters for improving the electrical conductivity and sensing sensitivity of nanocomposites. Although the viscosity and flow index which are determined by the polymer chain structure can significantly influence the nanofiller dispersion, few systematic structural and physical analyses have been reported. In this study, a facile engineering strategy to control the polymer chain structure was designed and applied using quad-screw extrusion (QSE) capable of transferring high shear stresses. According to the increase in rotation speed of the QSE, low molecular weight polymer chains with relatively uniform chain length were prepared, enabling the fabrication of a nanocomposite with uniform dispersion. Compared to the controls, when the optimized matrix (2000 rpm) was applied to the nanocomposite with 1 wt% multi-walled carbon nanotubes, the improved strain sensor sensitivity of 798.3% were achieved owing to the improved filler dispersion and electrical conductivity.