Styrene-butadiene-styrene block copolymer modified bitumen with ultraviolet absorbent intercalated layered double hydroxide: Compatibility and anti-ageing properties

Abstract

2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (ultraviolet absorbent, BP) intercalated layered double hydroxide (LDH) was synthesized to enhance the anti-ageing properties of styrene–butadiene–styrene block copolymer (SBS) modified bitumen (SMB). X-ray diffraction and UV–vis spectroscopy indicated that BP has been successfully substituted into LDH interlamination, and BP intercalated LDH (BP-LDH) exhibited better UV absorptive capacity than LDH. Then, the physical and rheological properties, chemical structure of BP-LDH and LDH modified SMB before and after ageing were comprehensively studied. Compared with LDH, BP-LDH possessed the smaller difference in solubility parameters (δ) and the stronger interaction energy (Einter) with SMB, resulting in the better compatibility of BP-LDH modified SMB. The high-temperature stability of SMB was promoted with the addition of BP-LDH or LDH, especially BP-LDH. After ageing, the temperature susceptibility, low-temperature anti-cracking and anti-fatigue cracking of SMB were deteriorated, the oxygen-containing groups (C = O and S = O) in SMB noticeably increased and carbon–carbon double bond (C = C) concurrently decreased. LDH could mitigate the ruin of ageing on the performance and chemical structures of SMB, and strengthen the anti-ageing performance. Furthermore, BP intercalated modification could further significantly heighten the performance of LDH.