Electrospinning strategy for the preparation of nano-porous fibers as modifier for inducing the network structure and enhancing mechanical properties of SBS-modified asphalt

Electrospinning is used to control the interface structure of macro-polyacrylonitrile (PAN) fibers, and nano-porous fibers (E-PAN) which possess enhanced adhesion and interface effects. Herein, E-PAN was prepared via electrospinning and was in turn incorporated into styrene-butadiene-styrene (SBS) asphalt to prepare PAN modified asphalt. The effect of E-PAN addition on the performance of modified asphalt was explored. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy (AFM), and AFM tests confirmed that E-PAN exhibited a highly rough nano-porous skeleton without any prominent structural damage during the preparation process. The three major indexes, dynamic shearing rheometer, MSCR, rotational viscosity, and thermogravimetric analysis tests results showed that E-PAN modified asphalt exhibited excellent viscoelasticity, anti-rutting and anti-fatigue properties and thermal stability (T HRI of 192.7°C). FT-IR test of the four components of modified asphalt confirmed that E-PAN chemically crosslinked with the saturates and aromatics in the base asphalt and SBS, which resulted in a uniform and well-developed network structure. In addition, Brauner-Emmett-Teller and fluorescence microscopy results confirmed that E-PAN got fully swollen in a behavior similar to that of SBS in the base asphalt, and hence helped SBS to form an excellent network structure in asphalt. E-PAN played the important role of stress buffer, mutual entanglement, and good thermal insulation inside the asphalt.