Preparation of hyperbranch-structured polyester fiber via thiol-ene click reaction under UV light irradiation for asphalt binder modification

This study reports the application of UV induced “thiol-ene click reaction” by coupling the covalent bonds of venyl-terminated dendritic polyester (VTDP) and polyester (PET) fiber and resulting in the fabrication of hyperbranch-structured PET named as VTDP-PET fiber. The PET fiber or VTDP-PET fiber as additives were blended with styrene-butadiene-styrene modified asphalt (SBSMA) to prepare fiber/SBSMAs. Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry, and X-ray photoelectron spectroscopy characterizations indicated that VTDP-PET fiber was linked with spherical three-dimensional dendritic molecular structure. Cone penetration, dynamic shear rheometer, multistress creep recovery, and thermogravimetric analysis tests showed that VTDP-PET/SBSMA exhibited enhanced resistance to flow, viscoelasticity, resistance against rutting, and thermal stability as compared to those of PET/SBSMA. The newly designed PET fiber and VTDP-PET fiber can be envisioned as effective alternative candidate for the fabricated of modified SBSMA with enhanced performances for practical applications in construction and highway industries.