Piezoelectric properties and microstructural changes of smart asphalt-based composites containing electroactive polymer and carbon black

Abstract

The requirements for smart asphalt pavement with piezoelectric properties are becoming necessary as the demand for clean energy and intelligent transportation are increased. To develop asphalt-based composite with electroactive performance for pavement electricity generation and to recycle battery waste, carbon black was first added to polyvinylidene fluoride-hexafluoropropylene to prepare electroactive polymer modifier (EPM) with high content of electroactive crystalline phases. Then carbon black and EPM were added into asphalt to prepare asphalt-based composites containing electroactive polymer (ACEP). The Output voltage, environmental scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and basic performance tests were conducted to study the piezoelectric properties, microstructural changes, electroactivity generation mechanism and basic performance of ACEP. The result shows that 5 % EPM has good dispersion, and stable crystallization rate of about 26 % and considerable electroactive crystalline phase content in asphalt, but more holes and defects inside ACEP appears when EPM is excessive. Also, the addition of EPM can slightly improve low-temperature property and thermal stability of ACEP. This is because the F element in EPM can interact with the polar groups in the gum and asphaltene. The 5 % ACEP sample with a thickness of 5 mm can output a voltage of about 260 mV. The penetration, ductility and softening point of 5 % ACEP were 55.2 dmm, 285 mm and 62.3°C, respectively. It is found that ACEP has a good combination of piezoelectric and basic pavement properties and can be used to build smart asphalt pavement with piezoelectric properties. This also provides a way to recycle battery waste.