Thiol‐ene click chemistry for constructing transition layer to enhance the interface interaction between polyacrylonitrile fiber and styrene‐butadiene‐styrene modified asphalt

Abstract Based on the high chemical stability and excellent end‐group functionalization capability of polyhedral oligomeric silsesquioxane (POSS), this study utilized thiol‐functionalized POSS (POSS‐SH) in a click chemistry reaction with styrene‐butadiene‐styrene triblock copolymer (SBS). The objective was to design a functional group forming a chemical bond with the polymer matrix, resulting in the preparation of thiol‐functionalized polyacrylonitrile (PAN) fibers chemically cross‐linked with POSS‐SH/PAN/SBS hybrid material. This hybrid material not only enhanced the compatibility between the components but also facilitated a connection between the fiber and SBS, thereby improving the mechanical properties of the modified asphalt. Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM), and atomic force microscopy analyses confirmed the successful modification of POSS‐SH/PAN fibers. FESEM analysis of the modified asphalt verified that POSS‐SH/PAN fibers contributed to strengthening the interfacial performance between the fiber and asphalt. Cone penetration and dynamic shear rheometer tests indicated that, compared to SBS‐modified asphalt, PAN/SBS and POSS‐SH/PAN/SBS‐modified asphalt exhibited enhanced shear strength, deformation resistance, and viscoelastic properties. Additionally, at 46°C, the storage modulus (G′) of 1.5% POSS‐SH/PAN/SBS‐modified asphalt increased by 11% compared to 1.5% PAN/SBS asphalt, with increases of 13.75% and 10.8% in loss modulus (G″) and complex modulus (G*), respectively.